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Search for "hydrogen peroxide" in Full Text gives 119 result(s) in Beilstein Journal of Organic Chemistry.
An uracil-linked hydroxyflavone probe for the recognition of ATP
- Márton Bojtár,
- Péter Zoltán Janzsó-Berend,
- Dávid Mester,
- Dóra Hessz,
- Mihály Kállay,
- Miklós Kubinyi and
- István Bitter
Beilstein J. Org. Chem. 2018, 14, 747–755, doi:10.3762/bjoc.14.63
- alkaline hydrogen peroxide to obtain the clickable fluorophore. All new compounds were characterized by NMR and high-resolution mass spectrometry. Optical spectroscopy The solubility of the UHF probe was very poor in water which resulted in the decrease of fluorescence over time upon dilution from the
- -hydroxy-7-propargyloxy-4H-chromen-4-one (3): Chalcone 2 (500 mg, 1.56 mmol) was dissolved in ethanol (25 mL) and sodium hydroxide (700 mg, 17.6 mmol, 11 equiv), dissolved in water (12.5 mL), was added. To the deep red solution was added 0.75 mL 30% hydrogen peroxide and the mixture was stirred at room
- analytes were added in 0.3 mM concentration. Ratio of the fluorescence intensities at 540 nm, the samples were excited at 470 and 400 nm. The red curve represents the result of a non-linear fitting. Synthesis of UHF. (i) 4-Dimethylaminobenzaldehyde, DMF, NaOMe, rt, 17 h, (ii) hydrogen peroxide, NaOH
Graphical Abstract
Figure 1: Structures of the studied hydroxyflavone derivatives.
Figure 2: Optimized geometries for (a) DEHF∙ATP, (b) UHF∙ATP with the adenine of ATP “sandwiched” between the...
Scheme 1: Synthesis of UHF. (i) 4-Dimethylaminobenzaldehyde, DMF, NaOMe, rt, 17 h, (ii) hydrogen peroxide, Na...
Figure 3: Variation of fluorescence spectra of UHF (1.0 μM) upon addition of increasing amounts of ATP in 0.0...
Figure 4: Excitation spectra of UHF (dark green line, 1 μM) and UHF + 300 equiv ATP (red line), measured at d...
Figure 5: Fluorescence enhancement (F/F0) values of UHF (1.0 μM) upon addition of different nucleotides at 54...
Figure 6: Ratio of the fluorescence intensities at 540 nm, the samples were excited at 470 and 400 nm. The re...
Nanoreactors for green catalysis
- M. Teresa De Martino,
- Loai K. E. A. Abdelmohsen,
- Floris P. J. T. Rutjes and
- Jan C. M. van Hest
Beilstein J. Org. Chem. 2018, 14, 716–733, doi:10.3762/bjoc.14.61
- of glucose oxidase (GOx) to convert glucose into D-glucono-δ-lactone and hydrogen peroxide was the first step of the reaction (Scheme 3A); subsequently, myoglobin (Myo) employed the hydrogen peroxide produced to oxidize guaiacol to quinone and water (Scheme 3B). When the pH was below 7, the
Graphical Abstract
Figure 1: Assembly of catalyst-functionalized amphiphilic block copolymers into polymer micelles and vesicles...
Scheme 1: C–N bond formation under micellar catalyst conditions, no organic solvent involved. Adapted from re...
Scheme 2: Suzuki−Miyaura couplings with, or without, ppm Pd. Conditions: ArI 0.5 mmol 3a, Ar’B(OH)2 (0.75–1.0...
Figure 2: PQS (4a), PQS attached proline catalyst 4b. Adapted from reference [26]. Copyright 2012 American Chemic...
Figure 3: 3a) Schematic representation of a Pickering emulsion with the enzyme in the water phase (i), or wit...
Scheme 3: Cascade reaction with GOx and Myo. Adapted from reference [82].
Figure 4: Cross-linked polymersomes with Cu(OTf)2 catalyst. Reprinted with permission from [15].
Figure 5: Schematic representation of enzymatic polymerization in polymersomes. (A) CALB in the aqueous compa...
Figure 6: Representation of DSN-G0. Reprinted with permission from [100].
Figure 7: The multivalent esterase dendrimer 5 catalyzes the hydrolysis of 8-acyloxypyrene 1,3,6-trisulfonate...
Figure 8: Conversion of 4-NP in five successive cycles of reduction, catalyzed by Au@citrate, Au@PEG and Au@P...
Biocatalytic synthesis of the Green Note trans-2-hexenal in a continuous-flow microreactor
- Morten M. C. H. van Schie,
- Tiago Pedroso de Almeida,
- Gabriele Laudadio,
- Florian Tieves,
- Elena Fernández-Fueyo,
- Timothy Noël,
- Isabel W. C. E. Arends and
- Frank Hollmann
Beilstein J. Org. Chem. 2018, 14, 697–703, doi:10.3762/bjoc.14.58
- spectrophotometer, following the oxidation of ABTS (ε405 = 36,800 M−1 cm−1) by horseradish peroxidase (POD) at the expense of hydrogen peroxide. In general, 0.044 µM PeAAOx was used to convert 3 mM of trans-2-hex-2-enol. The hydrogen peroxide formed in this reaction was subsequently used to convert 2 mM of ABTS to
Graphical Abstract
Scheme 1: Enzymatic reaction schemes for the selective oxidation of trans-hex-2-enol. A: Alcohol dehydrogenas...
Figure 1: Michaelis–Menten kinetics of the PeAAOx-catalysed oxidation of trans-hex-2-enol. Conditions: 50 mM ...
Figure 2: The influence of the residence time on the conversion of trans-hex-2-enol (red squares) to trans-2-...
Figure 3: Increasing the PeAAOx turnover numbers (TN) by increasing the residence time. Conditions: 6 mL flow...
One-pot preparation of 4-aryl-3-bromocoumarins from 4-aryl-2-propynoic acids with diaryliodonium salts, TBAB, and Na2S2O8
- Teppei Sasaki,
- Katsuhiko Moriyama and
- Hideo Togo
Beilstein J. Org. Chem. 2018, 14, 345–353, doi:10.3762/bjoc.14.22
- [27], with R-CH=O/(n-Bu)4NBr (TBAB, cat.)/K2S2O8 at 90 °C [28], with ArSO2H/Eosin Y(cat.)/tert-butyl hydrogen peroxide (TBHP) at rt [29], and with ArSO2NHNH2/n-Bu4NI(cat.)/TBHP at 80 °C [30]. In addition, the formation of coumarins via the bromine-radical-mediated reaction of aryl 2-alkynoates with
Graphical Abstract
Scheme 1: One-pot preparation of 4-aryl-3-bromocoumarins 3 from 3-aryl-2-propynoic acids 1 with diphenyliodon...
Scheme 2: One-pot preparation of 3-bromo-4-phenylcoumarins 3a from 3-phenyl-2-propynoic acid (1a) with daryli...
Scheme 3: Derivatization of 3-bromo-4-phenylcoumarin.
Figure 1: ORTEP of 3-bromo-7-chloro-4-phenylcoumarin (3Da).
Scheme 4: Possible reaction pathway.
5-Aminopyrazole as precursor in design and synthesis of fused pyrazoloazines
- Ranjana Aggarwal and
- Suresh Kumar
Beilstein J. Org. Chem. 2018, 14, 203–242, doi:10.3762/bjoc.14.15
- pyrazolo[3,4-d]pyrimidine derivatives starting from 5-amino-4-cyanopyrazoles 208 (Scheme 57). 5-Amino-4-cyanopyrazole 208 was benzoylated with p-nitrobenzoyl chloride (209) and subsequently cyclized to pyrazolo[3,4-d]pyrimidine derivative 211 by refluxing in sodium hydroxide and hydrogen peroxide
Graphical Abstract
Figure 1: Selected examples of drugs with fused pyrazole rings.
Figure 2: Typical structures of some fused pyrazoloazines from 5-aminopyrazoles.
Scheme 1: Regiospecific synthesis of 4 and 6-trifluoromethyl-1H-pyrazolo[3,4-b]pyridines.
Scheme 2: Synthesis of pyrazolo[3,4-b]pyridine-6-carboxylates.
Scheme 3: Synthesis of 1,4,6-triaryl-1H-pyrazolo[3,4-b]pyridines with ionic liquid .
Scheme 4: Synthesis of coumarin-based isomeric tetracyclic pyrazolo[3,4-b]pyridines.
Scheme 5: Synthesis of 6-substituted pyrazolo[3,4-b]pyridines under Heck conditions.
Scheme 6: Microwave-assisted palladium-catalyzed synthesis of pyrazolo[3,4-b]pyridines.
Scheme 7: Acid-catalyzed synthesis of pyrazolo[3,4-b]pyridines via enaminones.
Scheme 8: Synthesis of pyrazolo[3,4-b]pyridines via aza-Diels–Alder reaction.
Scheme 9: Synthesis of macrocyclane fused pyrazolo[3,4-b]pyridine derivatives.
Scheme 10: Three-component synthesis of 4,7-dihydro-1H-pyrazolo[3,4-b]pyridine derivatives.
Scheme 11: Ultrasonicated synthesis of spiro[indoline-3,4'-pyrazolo[3,4-b]pyridine]-2,6'(1'H)-diones.
Scheme 12: Synthesis of spiro[indoline-3,4'-pyrazolo[3,4-b]pyridine] derivatives under conventional heating co...
Scheme 13: Nanoparticle-catalyzed synthesis of pyrazolo[3,4-b]pyridine-spiroindolinones.
Scheme 14: Microwave-assisted multicomponent synthesis of spiropyrazolo[3,4-b]pyridines.
Scheme 15: Unexpected synthesis of naphthoic acid-substituted pyrazolo[3,4-b]pyridines.
Scheme 16: Multicomponent synthesis of variously substituted pyrazolo[3,4-b]pyridine derivatives.
Scheme 17: Three-component synthesis of 4,7-dihydropyrazolo[3,4-b]pyridines and pyrazolo[3,4-b]pyridines.
Scheme 18: Synthesis of pyrazolo[3,4-b]pyridine-5-spirocycloalkanediones.
Scheme 19: Ultrasound-mediated three-component synthesis of pyrazolo[3,4-b]pyridines.
Scheme 20: Multicomponent synthesis of 4-aryl-3-methyl-1-phenyl-4,6,8,9-tetrahydropyrazolo [3,4-b]thiopyrano[4...
Scheme 21: Synthesis of 2,3-dihydrochromeno[4,3-d]pyrazolo[3,4-b]pyridine-1,6-diones.
Scheme 22: FeCl3-catalyzed synthesis of o-hydroxyphenylpyrazolo[3,4-b]pyridine derivatives.
Scheme 23: Ionic liquid-mediated synthesis of pyrazolo[3,4-b]pyridines.
Scheme 24: Microwave-assisted synthesis of pyrazolo[3,4-b]pyridines.
Scheme 25: Multicomponent synthesis of pyrazolo[3,4-b]pyridine-5-carbonitriles.
Scheme 26: Unusual domino synthesis of 4,7-dihydropyrazolo[3,4-b]pyridine-5-nitriles.
Scheme 27: Synthesis of 4,5,6,7-tetrahydro-4H-pyrazolo[3,4-b]pyridines under conventional heating and ultrasou...
Scheme 28: L-Proline-catalyzed synthesis of of pyrazolo[3,4-b]pyridine.
Scheme 29: Microwave-assisted synthesis of 5-aminoarylpyrazolo[3,4-b]pyridines.
Scheme 30: Microwave-assisted multi-component synthesis of pyrazolo[3,4-e]indolizines.
Scheme 31: Synthesis of fluoropropynyl and fluoroalkyl substituted pyrazolo[1,5-a]pyrimidine.
Scheme 32: Acid-catalyzed synthesis of pyrazolo[1,5-a]pyrimidine derivatives.
Scheme 33: Chemoselective and regiospecific synthesis of 2-(3-methylpyrazol-1’-yl)-5-methylpyrazolo[1,5-a]pyri...
Scheme 34: Regioselective synthesis of 7-trifluoromethylpyrazolo[1,5-a]pyrimidines.
Scheme 35: Microwave-assisted synthesis of 7-trifluoromethylpyrazolo[1,5-a]pyrimidine carboxylates.
Scheme 36: Microwave and ultrasound-assisted synthesis of 7-trifluoromethylpyrazolo[1,5-a]pyrimidines.
Scheme 37: Base-catalyzed unprecedented synthesis of pyrazolo[1,5-a]pyrimidines via C–C bond cleavage.
Scheme 38: Synthesis of aminobenzothiazole/piperazine linked pyrazolo[1,5-a]pyrimidines.
Scheme 39: Synthesis of aminoalkylpyrazolo[1,5-a]pyrimidine-7-amines.
Scheme 40: Synthesis of pyrazolo[1,5-a]pyrimidines from condensation of 5-aminopyrazole 126 and ethyl acetoace...
Scheme 41: Synthesis of 7-aminopyrazolo[1,5-a]pyrimidines.
Scheme 42: Unexpected synthesis of 7-aminopyrazolo[1,5-a]pyrimidines under solvent free and solvent-mediated c...
Scheme 43: Synthesis of N-(4-aminophenyl)-7-aryloxypyrazolo[1,5-a]pyrimidin-5-amines.
Scheme 44: Base-catalyzed synthesis of 5,7-diarylpyrazolo[1,5-a]pyrimidines.
Scheme 45: Synthesis of 6,7-dihydropyrazolo[1,5-a]pyrimidines in PEG-400.
Scheme 46: Synthesis of 7-heteroarylpyrazolo[1,5-a]pyrimidine-3-carboxamides.
Scheme 47: Synthesis of 7-heteroarylpyrazolo[1,5-a]pyrimidine derivatives under conventional heating and micro...
Scheme 48: Synthesis of N-aroylpyrazolo[1,5-a]pyrimidine-5-amines.
Scheme 49: Regioselective synthesis of ethyl pyrazolo[1,5-a]pyrimidine-7-carboxylate.
Scheme 50: Sodium methoxide-catalyzed synthesis of 3-cyano-6,7-diarylpyrazolo[1,5-a]pyrimidines.
Scheme 51: Synthesis of various pyrazolo[3,4-d]pyrimidine derivatives.
Scheme 52: Synthesis of hydrazinopyrazolo[3,4-d]pyrimidine derivatives.
Scheme 53: Synthesis of N-arylidinepyrazolo[3,4-d]pyrimidin-5-amines.
Scheme 54: Synthesis of pyrazolo[3,4-d]pyrimidinyl-4-amines.
Scheme 55: Iodine-catalyzed synthesis of pyrazolo[3,4-d]pyrimidinones.
Scheme 56: Synthesis of ethyl 6-amino-2H-pyrazolo[3,4-d]pyrimidine-4-carboxylate.
Scheme 57: Synthesis of 4-substituted-(3,6-dihydropyran-4-yl)-1H-pyrazolo[3,4-d]pyrimidines.
Scheme 58: Synthesis of 1-(2,4-dichlorophenyl)pyrazolo[3,4-d]pyrimidin-4-yl carboxamides.
Scheme 59: Synthesis of 5-(1,3,4-thidiazol-2-yl)pyrazolo[3,4-d]pyrimidine.
Scheme 60: One pot POCl3-catalyzed synthesis of 1-arylpyrazolo[3,4-d]pyrimidin-4-ones.
Scheme 61: Synthesis of 4-amino-N1,C3-dialkylpyrazolo[3,4-d]pyrimidines under Suzuki conditions.
Scheme 62: Microwave-assisted synthesis of pyrazolo[3,4-b]pyrazines.
Scheme 63: Synthesis and derivatization of pyrazolo[3,4-b]pyrazine-5-carbonitriles.
Scheme 64: Synthesis of 2-thioxo-pyrazolo[1,5-a][1,3,5]triazin-4-ones.
Scheme 65: Synthesis of 2,3-dihydropyrazolo[1,5-a][1,3,5]triazin-4(1H)-one.
Scheme 66: Synthesis of pyrazolo[1,5-a][1,3,5]triazine-8-carboxylic acid ethyl ester.
Scheme 67: Microwave-assisted synthesis of 4,7-dihetarylpyrazolo[1,5-a][1,3,5]triazines.
Scheme 68: Alternative synthetic route to 4,7-diheteroarylpyrazolo[1,5-a][1,3,5]triazines.
Scheme 69: Synthesis of 4-aryl-2-ethylthio-7-methylpyrazolo[1,5-a][1,3,5]triazines.
Scheme 70: Microwave-assisted synthesis of 4-aminopyrazolo[1,5-a][1,3,5]triazine.
Scheme 71: Synthesis of pyrazolo[3,4-d][1,2,3]triazines from pyrazol-5-yl diazonium salts.
Scheme 72: Synthesis of 2,5-dihydropyrazolo[3,4-e][1,2,4]triazines.
Scheme 73: Synthesis of pyrazolo[5,1-c][1,2,4]triazines via diazopyrazolylenaminones.
Scheme 74: Synthesis of pyrazolo[5,1-c][1,2,4]triazines in presence of sodium acetate.
Scheme 75: Synthesis of various 7-diazopyrazolo[5,1-c][1,2,4]triazine derivatives.
Scheme 76: One pot synthesis of pyrazolo[5,1-c][1,2,4]triazines.
Scheme 77: Synthesis of 4-amino-3,7,8-trinitropyrazolo-[5,1-c][1,2,4]triazines.
Scheme 78: Synthesis of tricyclic pyrazolo[5,1-c][1,2,4]triazines by azocoupling reaction.
Photocatalytic formation of carbon–sulfur bonds
- Alexander Wimmer and
- Burkhard König
Beilstein J. Org. Chem. 2018, 14, 54–83, doi:10.3762/bjoc.14.4
- radical anion then deprotonates the thiyl radical cation. Subsequent addition to the alkene yields the anti-Markovnikov radical intermediate. Radical addition to dioxygen leads finally to the β-ketosulfide, which subsequently is oxidized by the in situ generated hydrogen peroxide radical to the respective
- β-ketosulfoxide. No additional sacrificial substrates are needed in order to regenerate the photocatalyst or for the oxidation of the sulfenyl intermediate to the respective sulfoxide moiety. Hydrogen peroxide, which is generated as a byproduct, directly is consumed by oxidizing the sulfide to the
Graphical Abstract
Scheme 1: General overview over the sulfur-based substrates and reactive intermediates that are discussed in ...
Scheme 2: Photoredox-catalyzed radical thiol–ene reaction, applying [Ru(bpz)3](PF6)2 as photocatalyst.
Scheme 3: Photoredox-catalyzed thiol–ene reaction of aliphatic thiols with alkenes enabled by aniline derivat...
Scheme 4: Photoredox-catalyzed radical thiol–ene reaction for the postfunctionalization of polymers (a) and n...
Scheme 5: Photoredox-catalyzed thiol–ene reaction enabled by bromotrichloromethane as redox additive.
Scheme 6: Photoredox-catalyzed preparation of β-ketosulfoxides with Eosin Y as organic dye as photoredox cata...
Scheme 7: Greaney’s photocatalytic radical thiol–ene reaction, applying TiO2 nanoparticles as photocatalyst.
Scheme 8: Fadeyi’s photocatalytic radical thiol–ene reaction, applying Bi2O3 as photocatalyst.
Scheme 9: Ananikov’s photocatalytic radical thiol-yne reaction, applying Eosin Y as photocatalyst.
Scheme 10: Organocatalytic visible-light photoinitiated thiol–ene coupling, applying phenylglyoxylic acid as o...
Scheme 11: Xia’s photoredox-catalyzed synthesis of 2,3-disubstituted benzothiophenes, applying 9-mesityl-10-me...
Scheme 12: Wang’s metal-free photoredox-catalyzed radical thiol–ene reaction, applying 9-mesityl-10-methylacri...
Scheme 13: Visible-light benzophenone-catalyzed metal- and oxidant-free radical thiol–ene reaction.
Scheme 14: Visible-light catalyzed C-3 sulfenylation of indole derivatives using Rose Bengal as organic dye.
Scheme 15: Photocatalyzed radical thiol–ene reaction and subsequent aerobic sulfide-oxidation with Rose Bengal...
Scheme 16: Photoredox-catalyzed synthesis of diaryl sulfides.
Scheme 17: Photocatalytic cross-coupling of aryl thiols with aryl diazonium salts, using Eosin Y as photoredox...
Scheme 18: Photocatalyzed cross-coupling of aryl diazonium salts with cysteines in batch and in a microphotore...
Scheme 19: Fu’s [Ir]-catalyzed photoredox arylation of aryl thiols with aryl halides.
Scheme 20: Fu’s photoredox-catalyzed difluoromethylation of aryl thiols.
Scheme 21: C–S cross-coupling of thiols with aryl iodides via [Ir]-photoredox and [Ni]-dual-catalysis.
Scheme 22: C–S cross-coupling of thiols with aryl bromides, applying 3,7-bis-(biphenyl-4-yl)-10-(1-naphthyl)ph...
Scheme 23: Collin’s photochemical dual-catalytic cross-coupling of thiols with bromoalkynes.
Scheme 24: Visible-light-promoted C–S cross-coupling via intermolecular electron donor–acceptor complex format...
Scheme 25: Li’s visible-light photoredox-catalyzed thiocyanation of indole derivatives with Rose Bengal as pho...
Scheme 26: Hajra’s visible-light photoredox-catalyzed thiocyanation of imidazoheterocycles with Eosin Y as pho...
Scheme 27: Wang’s photoredox-catalyzed thiocyanation reaction of indoles, applying heterogeneous TiO2/MoS2 nan...
Scheme 28: Yadav’s photoredox-catalyzed α-C(sp3)–H thiocyanation reaction for tertiary amines, applying Eosin ...
Scheme 29: Yadav’s photoredox-catalyzed synthesis of 5-aryl-2-imino-1,3-oxathiolanes.
Scheme 30: Yadav’s photoredox-catalyzed synthesis of 1,3-oxathiolane-2-thiones.
Scheme 31: Li’s photoredox catalysis for the preparation of 2-substituted benzothiazoles, applying [Ru(bpy)3](...
Scheme 32: Lei’s external oxidant-free synthesis of 2-substituted benzothiazoles by merging photoredox and tra...
Scheme 33: Metal-free photocatalyzed synthesis of 2-aminobenzothiazoles, applying Eosin Y as photocatalyst.
Scheme 34: Metal-free photocatalyzed synthesis of 1,3,4-thiadiazoles, using Eosin Y as photocatalyst.
Scheme 35: Visible-light photoredox-catalyzed preparation of benzothiophenes with Eosin Y.
Scheme 36: Visible-light-induced KOH/DMSO superbase-promoted preparation of benzothiophenes.
Scheme 37: Jacobi von Wangelin’s photocatalytic approach for the synthesis of aryl sulfides, applying Eosin Y ...
Scheme 38: Visible-light photosensitized α-C(sp3)–H thiolation of aliphatic ethers.
Scheme 39: Visible-light photocatalyzed cross-coupling of alkyl and aryl thiosulfates with aryl diazonium salt...
Scheme 40: Visible-light photocatalyzed, controllable sulfenylation and sulfoxidation with organic thiosulfate...
Scheme 41: Rastogi’s photoredox-catalyzed methylsulfoxidation of aryl diazonium salts, using [Ru(bpy)3]Cl2 as ...
Scheme 42: a) Visible-light metal-free Eosin Y-catalyzed procedure for the preparation of vinyl sulfones from ...
Scheme 43: Visible-light photocatalyzed cross-coupling of sodium sulfinates with secondary enamides.
Scheme 44: Wang’s photocatalyzed oxidative cyclization of phenyl propiolates with sulfinic acids, applying Eos...
Scheme 45: Lei’s sacrificial oxidant-free synthesis of allyl sulfones by merging photoredox and transition met...
Scheme 46: Photocatalyzed Markovnikov-selective radical/radical cross-coupling of aryl sulfinic acids and term...
Scheme 47: Visible-light Eosin Y induced cross-coupling of aryl sulfinic acids and styrene derivatives, afford...
Scheme 48: Photoredox-catalyzed bicyclization of 1,7-enynes with sulfinic acids, applying Eosin Y as photocata...
Scheme 49: Visible-light-accelerated C–H-sulfinylation of arenes and heteroarenes.
Scheme 50: Visible-light photoredox-catalyzed β-selenosulfonylation of electron-rich olefins, applying [Ru(bpy)...
Scheme 51: Photocatalyzed preparation of β-chlorosulfones from the respective olefins and p-toluenesulfonyl ch...
Scheme 52: a) Photocatalyzed preparation of β-amidovinyl sulfones from sulfonyl chlorides. b) Preparation of β...
Scheme 53: Visible-light photocatalyzed sulfonylation of aliphatic tertiary amines, applying [Ru(bpy)3](PF6)2 ...
Scheme 54: Reiser’s visible-light photoredox-catalyzed preparation of β-hydroxysulfones from sulfonyl chloride...
Scheme 55: a) Sun’s visible-light-catalyzed approach for the preparation of isoquinolinonediones, applying [fac...
Scheme 56: Visible-light photocatalyzed sulfonylation/cyclization of vinyl azides, applying [Ru(bpy)3]Cl2 as p...
Scheme 57: Visible-light photocatalyzed procedure for the formation of β-ketosulfones from aryl sulfonyl chlor...
Scheme 58: Zheng’s method for the sulfenylation of indole derivatives, applying sulfonyl chlorides via visible...
Scheme 59: Cai’s visible-light induced synthesis of β-ketosulfones from sulfonyl hydrazines and alkynes.
Scheme 60: Photoredox-catalyzed approach for the preparation of vinyl sulfones from sulfonyl hydrazines and ci...
Scheme 61: Jacobi von Wangelin’s visible-light photocatalyzed chlorosulfonylation of anilines.
Scheme 62: Three-component photoredox-catalyzed synthesis of N-amino sulfonamides, applying PDI as organic dye....
Scheme 63: Visible-light induced preparation of complex sulfones from oximes, silyl enol ethers and SO2.
Synthesis and photophysical properties of novel benzophospholo[3,2-b]indole derivatives
- Mio Matsumura,
- Mizuki Yamada,
- Atsuya Muranaka,
- Misae Kanai,
- Naoki Kakusawa,
- Daisuke Hashizume,
- Masanobu Uchiyama and
- Shuji Yasuike
Beilstein J. Org. Chem. 2017, 13, 2304–2309, doi:10.3762/bjoc.13.226
- ]indole 3 in 66% yield. Then, the chemical modification of the phosphorus atom of 3 was carried out and the results are shown in Scheme 2. The treatment of 3 with hydrogen peroxide, elemental sulfur, and elemental selenium afforded the corresponding phosphine oxide 4, sulfide 5, and selenide 6
Graphical Abstract
Figure 1: Phosphole-based tetracyclic heteroacenes.
Scheme 1: Synthesis of benzophospholo[3,2-b]indole 3.
Scheme 2: Chemical modifications of the phosphorus atom of 3.
Figure 2: ORTEP drawing of compound 3 (left) and 4 (right) with 50% probability. All hydrogen atoms are omitt...
Figure 3: UV–vis absorption (left) and normalized fluorescence emission (right, excitation at 335 nm) spectra...
Figure 4: The spatial plots of the HOMO and LUMO of compounds 3, 4, 7 and 9. The calculations were performed ...
Figure 5: The spatial plots of the selected molecular orbitals of compounds 5 and 6. The calculations were pe...
New bio-nanocomposites based on iron oxides and polysaccharides applied to oxidation and alkylation reactions
- Daily Rodríguez-Padrón,
- Alina M. Balu,
- Antonio A. Romero and
- Rafael Luque
Beilstein J. Org. Chem. 2017, 13, 1982–1993, doi:10.3762/bjoc.13.194
- supported iron oxide based catalytic systems [46] have been extensity reported to be active, stable and selective catalysts for the oxidation of alcohols with hydrogen peroxide. Specifically, the oxidation of benzyl alcohol to benzaldehyde has generated great interest in order to study the oxidation of
- was measured at room temperature at low frequency (470 Hz) using a Bartington MS-2 instrument. Catalytic experiments The oxidation of benzyl alcohol to benzaldehyde was performed using 25 mg of catalyst, 0.2 mL of benzyl alcohol, 0.3 mL of hydrogen peroxide, and 2 mL of acetonitrile as the solvent
Graphical Abstract
Figure 1: Overview of the preparation of the nanocomposites based on iron oxide and polysaccharide.
Figure 2: XPS spectra of A: Fe2O3-PS4, B: Fe2O3-PS4-MNP and C: TiO2-Fe2O3-PS4 nanohybrids.
Figure 3: A and B: SEM and TEM images of TiO2-Fe2O3-PS4; C and D: SEM and TEM images of Fe2O3-PS4. E and F: S...
Figure 4: DRIFT spectra of A: TiO2-Fe2O3-PS4 and B: Fe2O3-PS4-MNP nanohybrids.
Scheme 1: Oxidation of benzyl alcohol to benzaldehyde.
Figure 5: Conversion and selectivity of the oxidation of benzyl alcohol for the three catalytic systems.
Scheme 2: Microwave-assisted alkylation of toluene with benzyl chloride.
Figure 6: Conversion and selectivity of the microwave-assisted alkylation of toluene for the three catalytic ...
Scheme 3: Alkylation of toluene with benzyl chloride with conventional heating.
Figure 7: Conversion and selectivity of the alkylation of toluene with conventional heating for the three cat...
Figure 8: Reusability of the iron oxide/polysaccharide nanohybrids.
Chiral phase-transfer catalysis in the asymmetric α-heterofunctionalization of prochiral nucleophiles
- Johannes Schörgenhumer,
- Maximilian Tiffner and
- Mario Waser
Beilstein J. Org. Chem. 2017, 13, 1753–1769, doi:10.3762/bjoc.13.170
- -transfer reactions is hydrogen peroxide (H2O2). Unfortunately, the direct use of this base-chemical under asymmetric organocatalysis turned out to be rather tricky for α-hydroxylation reactions. One recent report by the Ooi group overcame some of the limitations by using H2O2 in combination with
Graphical Abstract
Scheme 1: Generally accepted ion-pairing mechanism between the chiral cation Q+ of a PTC and an enolate and s...
Scheme 2: Reported asymmetric α-fluorination of β-ketoesters 1 using different chiral PTCs.
Scheme 3: Asymmetric α-fluorination of benzofuranones 4 with phosphonium salt PTC F1.
Scheme 4: Asymmetric α-fluorination of 1 with chiral phosphate-based catalysts.
Scheme 5: Anionic PTC-catalysed α-fluorination of enamines 7 and ketones 10.
Scheme 6: PTC-catalysed α-chlorination reactions of β-ketoesters 1.
Scheme 7: Shioiri’s seminal report of the asymmetric α-hydroxylation of 15 with chiral ammonium salt PTCs.
Scheme 8: Asymmetric ammonium salt-catalysed α-hydroxylation using oxygen together with a P(III)-based reduct...
Scheme 9: Asymmetric ammonium salt-catalysed α-photooxygenations.
Scheme 10: Asymmetric ammonium salt-catalysed α-hydroxylations using organic oxygen-transfer reagents.
Scheme 11: Asymmetric triazolium salt-catalysed α-hydroxylation with in situ generated peroxy imidic acid 24.
Scheme 12: Phase-transfer-catalysed dearomatization of phenols and naphthols.
Scheme 13: Ishihara’s ammonium salt-catalysed oxidative cycloetherification.
Scheme 14: Chiral phase-transfer-catalysed α-sulfanylation reactions.
Scheme 15: Chiral phase-transfer-catalysed α-trifluoromethylthiolation of β-ketoesters 1.
Scheme 16: Chiral phase-transfer-catalysed α-amination of β-ketoesters 1 using diazocarboxylates 38.
Scheme 17: Asymmetric α-fluorination of benzofuranones 4 using diazocarboxylates 38 in the presence of phospho...
Scheme 18: Anionic phase-transfer-catalysed α-amination of β-ketoesters 1 with aryldiazonium salts 41.
Scheme 19: Triazolium salt L-catalysed α-amination of different prochiral nucleophiles with in situ activated ...
Scheme 20: Phase-transfer-catalysed Neber rearrangement.
The chemistry and biology of mycolactones
- Matthias Gehringer and
- Karl-Heinz Altmann
Beilstein J. Org. Chem. 2017, 13, 1596–1660, doi:10.3762/bjoc.13.159
Graphical Abstract
Figure 1: Initial proposal for the core macrolactone structure (left) and the established complete structure ...
Figure 2: Mycolactone congeners and their origins.
Figure 3: Misassigned mycolactone E structure according to Small et al. [50] (11) and the correct structure (6) f...
Figure 4: Schematic illustration of Kishi’s improved mycolactone TLC detection method exploiting derivatizati...
Figure 5: Fluorescent probes derived from natural mycolactone A/B (1a,b) or its synthetic 8-desmethyl analogs...
Figure 6: Tool compounds used by Pluschke and co-workers for elucidating the molecular targets of mycolactone...
Figure 7: Synthetic strategies towards the extended mycolactone core. A) General strategies. B) Kishi’s appro...
Scheme 1: Kishi’s 1st generation approach towards the extended core structure of mycolactones. Reagents and c...
Scheme 2: Kishi’s 2nd generation approach towards the extended core structure of mycolactones. Reagents and c...
Scheme 3: Kishi’s 3rd generation approach towards the extended core structure of mycolactones. Reagents and c...
Scheme 4: Negishi’s synthesis of the extended core structure of mycolactones. Reagents and conditions: a) (i) ...
Scheme 5: Burkart’s (incomplete) 1st generation approach towards the extended core structure of mycolactones....
Scheme 6: Burkart’s (incomplete) 1st, 2nd and 3rd generation approach towards the extended mycolactone core s...
Scheme 7: Altmann’s synthesis of alkyl iodide 91. Reagents and conditions: a) (i) PMB-trichloroacetimidate, T...
Scheme 8: Final steps of Altmann’s synthesis of the extended core structure of mycolactones. Reagents and con...
Scheme 9: Basic principles of the Aggarwal lithiation–borylation homologation process [185,186].
Scheme 10: Aggarwal’s synthesis of the C1–C11 fragment of the mycolactone core. Reagents and conditions: a) Cl...
Scheme 11: Aggarwal’s synthesis of the linear C1–C20 fragment of the mycolactone core. Reagents and conditions...
Figure 8: Synthetic strategies towards the mycolactone A/B lower side chain.
Scheme 12: Gurjar and Cherian’s synthesis of the C1’–C8’ fragment of the mycolactone A/B pentaenoate side chai...
Scheme 13: Gurjar and Cherian’s synthesis of the benzyl-protected mycolactone A/B pentaenoate side chain. Reag...
Scheme 14: Kishi’s synthesis of model compounds for elucidating the stereochemistry of the C7’–C16’ fragment o...
Scheme 15: Kishi’s synthesis of the mycolactone A/B pentaenoate side chain. (a) (i) NaH, (EtO)2P(O)CH2CO2Et, T...
Scheme 16: Feringa and Minnaard's incomplete synthesis of mycolactone A/B pentaenoate side chain. Reagents and...
Scheme 17: Altmann’s approach towards the mycolactone A/B pentaenoate side chain. Reagents and conditions: a) ...
Scheme 18: Negishi’s access to the C1’–C7’ fragment of mycolactone A. Reagents and conditions: a) (i) n-BuLi, ...
Scheme 19: Negishi’s approach to the C1’–C7’ fragment of mycolactone B. Reagents and conditions: a) (i) DIBAL-...
Scheme 20: Negishi’s synthesis of the C8’–C16’ fragment of mycolactone A/B. Reagents and conditions: a) 142, BF...
Scheme 21: Negishi’s assembly of the mycolactone A and B pentaenoate side chains. Reagents and conditions: a) ...
Scheme 22: Blanchard’s approach to the mycolactone A/B pentaenoate side chain. a) (i) Ph3P=C(Me)COOEt, CH2Cl2,...
Scheme 23: Kishi’s approach to the mycolactone C pentaenoate side chain exemplified for the 13’R,15’S-isomer 1...
Scheme 24: Altmann’s (unpublished) synthesis of the mycolactone C pentaenoate side chain. Reagents and conditi...
Scheme 25: Blanchard’s synthesis of the mycolactone C pentaenoate side chain. Reagents and conditions: a) (i) ...
Scheme 26: Kishi’s synthesis of the tetraenoate side chain of mycolactone F exemplified by enantiomer 165. Rea...
Scheme 27: Kishi’s synthesis of the mycolactone E tetraenoate side chain. Reagents and conditions: a) (i) CH2=...
Scheme 28: Wang and Dai’s synthesis of the mycolactone E tetraenoate side chain. Reagents and conditions: a) (...
Scheme 29: Kishi’s synthesis of the dithiane-protected tetraenoate side chain of the minor oxo-metabolite of m...
Scheme 30: Kishi’s synthesis of the mycolactone S1 and S2 pentaenoate side chains. Reagents and conditions: a)...
Scheme 31: Kishi’s 1st generation and Altmann’s total synthesis of mycolactone A/B (1a,b) and Negishi’s select...
Scheme 32: Kishi’s 2nd generation total synthesis of mycolactone A/B (1a,b). Reagents and conditions: a) 2,4,6...
Scheme 33: Blanchard’s synthesis of the 8-desmethylmycolactone core. Reagents and conditions: a) (i) TsCl, TEA...
Scheme 34: Altmann’s (partially unpublished) synthesis of the C20-hydroxylated mycolactone core. Reagents and ...
Scheme 35: Altmann’s and Blanchard’s approaches towards the 11-isopropyl-8-desmethylmycolactone core. Reagents...
Scheme 36: Blanchard’s synthesis of the saturated variant of the C11-isopropyl-8-desmethylmycolactone core. Re...
Scheme 37: Structure elucidation of photo-mycolactones generated from tetraenoate 224.
Scheme 38: Kishi’s synthesis of the linear precursor of the photo-mycolactone B1 lower side chain. Reagents an...
Scheme 39: Kishi’s synthesis of the photo-mycolactone B1 lower side chain. Reagents and conditions: a) LiTMP, ...
Scheme 40: Kishi’s synthesis of a stabilized lower mycolactone side chain. Reagents and conditions: a) (i) TBD...
Scheme 41: Blanchard’s variation of the C12’,C13’,C15’ stereocluster. Reagents and conditions: a) (i) DIBAL-H,...
Scheme 42: Blanchard’s synthesis of aromatic mycolactone polyenoate side chain analogs. Reagents and condition...
Scheme 43: Small’s partial synthesis of a BODIPY-labeled mycolactone derivative and Demangel’s partial synthes...
Scheme 44: Blanchard’s synthesis of the BODIPY-labeled 8-desmethylmycolactones. Reagents and conditions: a) (i...
Scheme 45: Altmann’s synthesis of biotinylated mycolactones. Reagents and conditions: a) (i) CDI, THF, rt, 2 d...
Figure 9: Kishi’s elongated n-butyl carbamoyl mycolactone A/B analog.
New electroactive asymmetrical chalcones and therefrom derived 2-amino- / 2-(1H-pyrrol-1-yl)pyrimidines, containing an N-[ω-(4-methoxyphenoxy)alkyl]carbazole fragment: synthesis, optical and electrochemical properties
- Daria G. Selivanova,
- Alexei A. Gorbunov,
- Olga A. Mayorova,
- Alexander N. Vasyanin,
- Igor V. Lunegov,
- Elena V. Shklyaeva and
- Georgii G. Abashev
Beilstein J. Org. Chem. 2017, 13, 1583–1595, doi:10.3762/bjoc.13.158
- ethanolic media resulted in the formation of 1,3-diarylsubstituted prop-2-en-1-ones 6a,b [23]. Cyclization of chalcones 6a,b with guanidine sulfate followed by oxidation with hydrogen peroxide gave rise to 2-amino-4,6-disubstituted pyrimidines 7a,b [24]. 2-(1H-Pyrrol-1-yl)pyrimidines 8a,b were synthesized
Graphical Abstract
Scheme 1: Synthesis of 9-[ω-(methoxyphenoxy)alkyl]-9H-carbazoles 1a,b.
Scheme 2: Synthesis of 9-[ω-(4-methoxyphenoxy)alkyl]-9H-carbazole-3-carbaldehydes 2a,b and 1-(5-arylthiophen-...
Scheme 3: Synthesis of quadrupolar chromophores 6a,b−8a,b.
Figure 1: Comparison of UV–vis absorption and fluorescence spectra of compounds 2a–5a (a) and 2b–5b (b) in CH...
Figure 2: Comparison of UV–vis absorption and fluorescence spectra of compounds 6a (a, b), 6b (c, d) in vario...
Figure 3: Comparison of UV–vis absorption and fluorescence spectra of compounds 7a (a, b) and 7b (c, d) in va...
Figure 4: Correlation between Kamlet–Taft π* parameters [29] and the absorption and emission maxima wavelength of...
Figure 5: Comparison of UV–vis absorption spectra of 2-amino-4,6-di(4-bromophenyl)pyrimidine and 2-amino-4-[4...
Figure 6: UV–vis absorption and fluorescence spectra of compounds 8a (a), 8b ( b) in CHCl3 (c = 10−4 mol L−1)....
Figure 7: Cyclic voltammograms of compounds 2b (a), 5b (b); WE – carbon-pyroceramic electrode, 10 cycles, Et4...
Figure 8: Cyclic voltammograms of compounds 6b (a), 7b (b), 8b (с); WE – carbon-pyroceramic electrode, 10 cyc...
Urea–hydrogen peroxide prompted the selective and controlled oxidation of thioglycosides into sulfoxides and sulfones
- Adesh Kumar Singh,
- Varsha Tiwari,
- Kunj Bihari Mishra,
- Surabhi Gupta and
- Jeyakumar Kandasamy
Beilstein J. Org. Chem. 2017, 13, 1139–1144, doi:10.3762/bjoc.13.113
- thioglycosides to corresponding glycosyl sulfoxides and sulfones is reported using urea–hydrogen peroxide (UHP). A wide range of glycosyl sulfoxides are selectively achieved using 1.5 equiv of UHP at 60 °C while corresponding sulfones are achieved using 2.5 equiv of UHP at 80 °C in acetic acid. Remarkably
- , oxidation susceptible olefin functional groups were found to be stable during the oxidation of sulfide. Keywords: monosaccharides; oxidation; sulfones; sulfoxides; thioglycosides; urea–hydrogen peroxide; Introduction Organosulfur compounds such as sulfides, sulfoxides and sulfones are useful intermediates
- , intolerance of other oxidation susceptible functional groups, etc. Thus, developing a mild and efficient method for the controlled oxidation of sulfides to corresponding glycosyl sulfoxides and sulfones, is of great interest. The utility of hydrogen peroxide–solid adducts in organic synthesis is well explored
Adsorption of RNA on mineral surfaces and mineral precipitates
- Elisa Biondi,
- Yoshihiro Furukawa,
- Jun Kawai and
- Steven A. Benner
Beilstein J. Org. Chem. 2017, 13, 393–404, doi:10.3762/bjoc.13.42
- thousand other variables that might influence these results [32]. Mitigating this concern is the fact that the patterns of adsorbance were unchanged in these experiments whether or not the mineral was cleaned by treating with hydrogen peroxide or diluted acid. However, as a cautionary note, we point to the
- , strontianite, and witherite, respectively). The magnesite specimen was from Minas Gerias, Brazil; the calcite was a specimen of "Iceland spar". The strontianite was obtained from the Minerva Mine in Illinois , and the witherite was obtained from Cave in Rock, Illinois. The specimens were washed with hydrogen
- peroxide (30%) followed by water and then ethanol to remove potential organic surface contaminants. The samples were then dried in air while covered. To flat surfaces of the cleaned mineral were added droplets of an aqueous (unbuffered) solution of 5’-32P labeled 83-mer RNA (2 µL, 50 nM). This length was
Graphical Abstract
Figure 1: Adsorption of RNA on natural carbonate mineral samples.
Figure 2: Co-precipitation experiments on carbonate minerals for RNA-binding competition. The precipitated co...
Figure 3: RNA-induced calcium carbonate polymorphism. A: Feigl’s stain of CaCO3 precipitate formed by double ...
Figure 4: RNA adsorbed on aragonite is resistant to thermal degradation in aqueous solution. 18% denaturing P...
Total synthesis of a Streptococcus pneumoniae serotype 12F CPS repeating unit hexasaccharide
- Peter H. Seeberger,
- Claney L. Pereira and
- Subramanian Govindan
Beilstein J. Org. Chem. 2017, 13, 164–173, doi:10.3762/bjoc.13.19
- employing a more nucleophilic and less basic reagent such as a lithium hydroxide/hydrogen peroxide mixture did not provide relief from the problem, but instead also produced a mixture of undesired products. Adjustments in the sequence of deprotection steps by first carrying out hydrogenolysis using Pd/C in
Graphical Abstract
Figure 1: Structure of the S. pneumoniae serotype 12F capsular polysaccharide repeating unit [15].
Scheme 1: Retrosynthetic analyses of the S. pneumoniae hexasaccharide 1.
Scheme 2: Attempted synthesis of mannosazide building block 15. Reagents and conditions: (a) levulinic acid, ...
Scheme 3: Synthesis of mannosazide building block 18. Reagents and conditions: (a) TBSCl, imidazole, DCM, 0 °...
Scheme 4: Synthesis of the reducing-end trisaccharide 3. Reagents and conditions: (a) TMSOTf, (CH3CH2)2O/CH2Cl...
Scheme 5: Synthesis of monosaccharide building blocks 8, 9 and 26. Reagents and conditions: (a) acetic anhydr...
Scheme 6: Synthesis of the non-reducing end trisaccharide 2. Reagents and conditions: (a) TMSOTf, CH2Cl2, −30...
Scheme 7: Attempted synthesis of hexasaccharide repeating unit 36 via a convergent [3 + 3] glycosylation stra...
Scheme 8: Linear assembly of fully protected hexasaccharide 51. Reagents and conditions: (a) DDQ, CH2Cl2/MeOH...
Scheme 9: Global deprotection to furnish S. pneumonia serotype 12F repeating unit hexasaccharide 1. Reagents ...
Stereo- and regioselectivity of the hetero-Diels–Alder reaction of nitroso derivatives with conjugated dienes
- Lucie Brulíková,
- Aidan Harrison,
- Marvin J. Miller and
- Jan Hlaváč
Beilstein J. Org. Chem. 2016, 12, 1949–1980, doi:10.3762/bjoc.12.184
- transformation, hydrogen peroxide and m-CPBA are the most popular (see examples in Scheme 4). In the literature, the oxidation of hydroxylamines is described most frequently using Fe(III) salts, m-CPBA or TBAPI and the reaction is performed exclusively using a solid-phase synthetic approach (see examples in
- chiral alkyl N-dienylpyroglutamates 190 with acylnitroso intermediates 191 generated through a Ru(II) or Ir(I)-catalyzed hydrogen peroxide oxidation of hydroxamic acids (Scheme 38) [143]. The Ru(II) complexes A–D have previously been reported [144] as efficient catalysts for the oxidation of hydroxamic
Graphical Abstract
Scheme 1: Nitroso hetero-Diels–Alder reaction.
Scheme 2: The hetero-Diels–Alder reaction between thebaine (4) and an acylnitroso dienophile 5.
Figure 1: Examples of nitroso dienophiles frequently used in hetero-Diels–Alder reaction studies.
Scheme 3: Synthesis of arylnitroso species by substitution of a trifluoroborate group [36].
Scheme 4: Synthesis of arylnitroso compounds by amine oxidation.
Scheme 5: Synthesis of arylnitroso compounds by hydroxylamine oxidation.
Scheme 6: Synthesis of chloronitroso compounds by the treatment of a nitronate anion with oxalyl chloride.
Scheme 7: Non-oxidative routes to acylnitroso species.
Figure 2: RB3LYP/6-31G* computed energies (in kcal·mol−1) and bond lengths for exo and endo-transition states...
Scheme 8: Hetero-Diels–Alder cycloadditions of diene 28 and nitroso dienophiles 29.
Figure 3: Relative reactivity (ΔE#) and regioselectivity (Δ) for hetero-Diels–Alder of 28 and nitroso dienoph...
Scheme 9: Reaction of chiral 1-phosphono-1,3-butadiene 31 with nitroso dienophiles 32.
Scheme 10: Hetero-Diels–Alder reactions of hydroxamic acids 35 with various dienes 37.
Scheme 11: General regioselectivity of the nitroso hetero-Diels–Alder reaction observed with unsymmetrical die...
Scheme 12: Effect of the nitroso species on the regioselectivity for weakly directing 2-substituted dienes.
Scheme 13: Regioselectivity of 1,4-disubstituted dienes 51.
Scheme 14: Nitroso hetero-Diels–Alder reaction between Boc-nitroso compound 54 and dienes 55.
Scheme 15: Nitroso hetero-Diels–Alder reaction between Wightman reagent 58 and dienes 59.
Scheme 16: Regioselective reaction of 3-dienyl-2-azetidinones 62 with nitrosobenzene (47).
Scheme 17: The regioselective reaction of 1,3-butadienes 65 with various nitroso heterodienophiles 66.
Scheme 18: Catalysis of the nitroso hetero-Diels–Alder reaction by vanadium in the presence of the oxidant CHP...
Figure 4: 1,2-Oxazines synthesized in solution with moderate to high regioselectivity, showing the favored re...
Figure 5: 1,2-Oxazines synthesized in the solid phase with moderate to high regioselectivity, showing the fav...
Scheme 19: Regioselectivity of solution-phase nitroso hetero-Diels–Alder reaction with acyl and aryl nitroso d...
Scheme 20: Favored regioisomeric outcome for the solution and solid-phase reactions, giving hetero-Diels–Alder...
Figure 6: Favored regioisomers and regioisomeric ratios for 1,2-oxazines synthesized in solid phase (91, 93, ...
Scheme 21: Regiocontrol of the reaction between 3-dienyl-2-azetidinones and nitrosobenzene due to change in a ...
Scheme 22: Regiocontrol of the reaction between diene 111 and 2-methyl-6-nitrosopyridine (112) due to metal co...
Scheme 23: Asymmetric hetero-Diels–Alder reactions reported by Vasella [56].
Scheme 24: Asymmetric hetero-Diels–Alder reaction of cyclohexa-1,3-diene (120) with acylnitroso dienophile 119....
Scheme 25: Asymmetric induction with L-proline derivatives 124–126.
Scheme 26: Asymmetric cycloaddition of the acylnitroso compound 136 to diene 135.
Scheme 27: Asymmetric induction with arylmenthol-based nitroso dienophiles 142.
Scheme 28: Cycloaddition of silyloxycyclohexadiene 145 to the acylnitroso dienophile derived from (+)-camphors...
Scheme 29: Asymmetric reaction of O-isopropylidene-protected cis-cyclohexa-3,5-diene-1,2-diol 147 with mannofu...
Scheme 30: Synthesis of synthon 152 from 2-methoxyphenol 150 and chiral auxiliary 151.
Scheme 31: Asymmetric nitroso hetero-Diels–Alder reaction with Wightman chloronitroso reagent 58.
Scheme 32: Asymmetric 1,2-oxazine synthesis using chiral cyclic diene 157 and the application of this reaction...
Scheme 33: Asymmetric 1,2-oxazine synthesis using a chiral diene reported by Jones et al. [75]. aRegioisomeric rat...
Scheme 34: The nitroso hetero-Diels–Alder reaction of acyclic oxazolidine-substituted diene 170 and chiral 1-s...
Scheme 35: The nitroso hetero-Diels–Alder reaction of acyclic lactam-substituted diene 176 with various acylni...
Scheme 36: The hetero-Diels–Alder reaction of acylnitroso dienophile.
Scheme 37: The hetero-Diels–Alder reaction of arylnitroso dienophiles using Lewis acids.
Scheme 38: Asymmetric hetero-Diels–Alder reactions of chiral alkyl N-dienylpyroglutamates.
Scheme 39: Catalytic asymmetric arylnitroso reaction between mono-substituted 1,3-cyclohexadiene 196 and disub...
Figure 7: Plausible chelate intermediate complexes formed during the hetero-Diels–Alder reaction to give 1,2-...
Scheme 40: Catalytic asymmetric nitroso hetero-Diels–Alder between cyclic dienes and 2-nitrosopyridine.
Scheme 41: The reason for the increased enantioselectivity of stereoisomer 212 compared with stereoisomer 213.
Scheme 42: The copper-catalyzed nitroso hetero-Diels–Alder reaction of 6-methyl-2-nitrosopyridine (199) with p...
Scheme 43: Asymmetric nitroso hetero-Diels–Alder reaction of nitrosoarenes with dienylcarbamates catalyzed by ...
Scheme 44: The enantioselective hetero-Diels–Alder reaction between nitrosobenzene and (E)-2,4-pentadien-1-ol (...
Scheme 45: Asymmetric nitroso hetero-Diels–Alder reaction using tartaric acid ester chelation of the diene and...
Rearrangements of organic peroxides and related processes
- Ivan A. Yaremenko,
- Vera A. Vil’,
- Dmitry V. Demchuk and
- Alexander O. Terent’ev
Beilstein J. Org. Chem. 2016, 12, 1647–1748, doi:10.3762/bjoc.12.162
- search for new synthetic methods for peroxides starting from carbonyl compounds, hydrogen peroxide, and hydroperoxides [121][122][123][124][125][126][127][128][129][130][131][132][133][134][135][136][137][138][139][140][141][142][143][144][145][146][147][148][149][150][151][152][153][154][155][156][157
- Smith rearrangements are of interest in allyl hydroperoxide transformations. 1.1 Baeyer–Villiger oxidation The BV reaction is the oxidation of ketones or aldehydes A under the action of hydrogen peroxide, hydroperoxides, Caro’s acid (H2SO5), or organic peracids to yield esters, lactones, or carboxylic
- . The BV oxidation is one of the most important reactions in organic chemistry because it produces lactones, which are useful synthetic products in polymer, agrochemical, and pharmaceutical industry. m-Chloroperbenzoic, peracetic, and perfluoroacetic acids, as well as hydrogen peroxide/protic acid
Graphical Abstract
Figure 1: The named transformations considered in this review.
Scheme 1: The Baeyer–Villiger oxidation.
Scheme 2: The general mechanism of the peracid-promoted Baeyer–Villiger oxidation.
Scheme 3: General mechanism of the Lewis acid-catalyzed Baeyer–Villiger rearrangement.
Scheme 4: The theoretically studied mechanism of the BV oxidation reaction promoted by H2O2 and the Lewis aci...
Scheme 5: Proton movements in the transition states of the Baeyer–Villiger oxidation.
Scheme 6: The dependence of the course of the Baeyer–Villiger oxidation on the type of O–O-bond cleavage in t...
Scheme 7: The acid-catalyzed Baeyer–Villiger oxidation of cyclic epoxy ketones 22.
Scheme 8: Oxidation of isophorone oxide 29.
Scheme 9: Synthesis of acyl phosphate 32 from acyl phosphonate 31.
Scheme 10: Synthesis of aflatoxin B2 (36).
Scheme 11: The Baeyer–Villiger rearrangement of ketones 37 to lactones 38.
Scheme 12: Synthesis of 3,4-dimethoxybenzoic acid (40) via Baeyer–Villiger oxidation.
Scheme 13: Oxone transforms α,β-unsaturated ketones 43 into vinyl acetates 44.
Scheme 14: The Baeyer–Villiger oxidation of ketones 45 using diaryl diselenide and hydrogen peroxide.
Scheme 15: Baeyer–Villiger oxidation of (E)-2-methylenecyclobutanones.
Scheme 16: Oxidation of β-ionone (56) by H2O2/(BnSe)2 with formation of (E)-2-(2,6,6-trimethylcyclohex-1-en-1-...
Scheme 17: The mechanism of oxidation of ketones 58a–f by hydrogen peroxide in the presence of arsonated polys...
Scheme 18: Oxidation of ketone (58b) by H2O2 to 6-methylcaprolactone (59b) catalyzed by Pt complex 66·BF4.
Scheme 19: Oxidation of ketones 67 with H2O2 in the presence of [(dppb}Pt(µ-OH)]22+.
Scheme 20: The mechanism of oxidation of ketones 67 in the presence of [(dppb}Pt(µ-OH)]22+ and H2O2.
Scheme 21: Oxidation of benzaldehydes 69 in the presence of the H2O2/MeReO3 system.
Scheme 22: Oxidation of acetophenones 72 in the presence of the H2O2/MeReO3 system.
Scheme 23: Baeyer–Villiger oxidation of 2-adamantanone (45c) in the presence of Sn-containing mesoporous silic...
Scheme 24: Aerobic Baeyer–Villiger oxidation of ketones 76 using metal-free carbon.
Scheme 25: A regioselective Baeyer-Villiger oxidation of functionalized cyclohexenones 78 into a dihydrooxepin...
Scheme 26: The oxidation of aldehydes and ketones 80 by H2O2 catalyzed by Co4HP2Mo15V3O62.
Scheme 27: The cleavage of ketones 82 with hydrogen peroxide in alkaline solution.
Scheme 28: Oxidation of ketones 85 to esters 86 with H2O2–urea in the presence of KHCO3.
Scheme 29: Mechanism of the asymmetric oxidation of cyclopentane-1,2-dione 87a with the Ti(OiPr)4/(+)DET/t-BuO...
Scheme 30: The oxidation of cis-4-tert-butyl-2-fluorocyclohexanone (93) with m-chloroperbenzoic acid.
Scheme 31: The mechanism of the asymmetric oxidation of 3-substituted cyclobutanone 96a in the presence of chi...
Scheme 32: Enantioselective Baeyer–Villiger oxidation of cyclic ketones 98.
Scheme 33: Regio- and enantioselective Baeyer–Villiger oxidation of cyclic ketones 101.
Scheme 34: The proposed mechanism of the Baeyer–Villiger oxidation of acetal 105f.
Scheme 35: Synthesis of hydroxy-10H-acridin-9-one 117 from tetramethoxyanthracene 114.
Scheme 36: The Baeyer–Villiger oxidation of the fully substituted pyrrole 120.
Scheme 37: The Criegee rearrangement.
Scheme 38: The mechanism of the Criegee reaction of a peracid with a tertiary alcohol 122.
Scheme 39: Criegee rearrangement of decaline ethylperoxoate 127 into ketal 128.
Scheme 40: The ionic cleavage of 2-methoxy-2-propyl perester 129.
Scheme 41: The Criegee rearrangement of α-methoxy hydroperoxide 136.
Scheme 42: Synthesis of enol esters and acetals via the Criegee rearrangement.
Scheme 43: Proposed mechanism of the transformation of 1-hydroperoxy-2-oxabicycloalkanones 147a–d.
Scheme 44: Transformation of 3-hydroxy-1,2-dioxolanes 151 into diketone derivatives 152.
Scheme 45: Criegee rearrangement of peroxide 153 with the mono-, di-, and tri-O-insertion.
Scheme 46: The sequential Criegee rearrangements of adamantanes 157a,b.
Scheme 47: Synthesis of diaryl carbonates 160a–d from triarylmethanols 159a–d through successive oxygen insert...
Scheme 48: The synthesis of sesquiterpenes 162 from ketone 161 with a Criegee rearrangement as one key step.
Scheme 49: Synthesis of trans-hydrindan derivatives 164, 165.
Scheme 50: The Hock rearrangement.
Scheme 51: The general scheme of the cumene process.
Scheme 52: The Hock rearrangement of aliphatic hydroperoxides.
Scheme 53: The mechanism of solvolysis of brosylates 174a–c and spiro cyclopropyl carbinols 175a–c in THF/H2O2....
Scheme 54: The fragmentation mechanism of hydroperoxy acetals 178 to esters 179.
Scheme 55: The acid-catalyzed rearrangement of phenylcyclopentyl hydroperoxide 181.
Scheme 56: The peroxidation of tertiary alcohols in the presence of a catalytic amount of acid.
Scheme 57: The acid-catalyzed reaction of bicyclic secondary alcohols 192 with hydrogen peroxide.
Scheme 58: The photooxidation of 5,6-disubstituted 3,4-dihydro-2H-pyrans 196.
Scheme 59: The oxidation of tertiary alcohols 200a–g, 203a,b, and 206.
Scheme 60: Transformation of functional peroxide 209 leading to 2,3-disubstitued furans 210 in one step.
Scheme 61: The synthesis of carbazoles 213 via peroxide rearrangement.
Scheme 62: The construction of C–N bonds using the Hock rearrangement.
Scheme 63: The synthesis of moiety 218 from 217 which is a structural motif in the antitumor–antibiotic of CC-...
Scheme 64: The in vivo oxidation steps of cholesterol (219) by singlet oxygen.
Scheme 65: The proposed mechanism of the rearrangement of cholesterol-5α-OOH 220.
Scheme 66: Photochemical route to artemisinin via Hock rearrangement of 223.
Scheme 67: The Kornblum–DeLaMare rearrangement.
Scheme 68: Kornblum–DeLaMare transformation of 1-phenylethyl tert-butyl peroxide (225).
Scheme 69: The synthesis 4-hydroxyenones 230 from peroxide 229.
Scheme 70: The Kornblum–DeLaMare rearrangement of peroxide 232.
Scheme 71: The reduction of peroxide 234.
Scheme 72: The Kornblum–DeLaMare rearrangement of endoperoxide 236.
Scheme 73: The rearrangement of peroxide 238 under Kornblum–DeLaMare conditions.
Scheme 74: The proposed mechanism of rearrangement of peroxide 238.
Scheme 75: The Kornblum–DeLaMare rearrangement of peroxides 242a,b.
Scheme 76: The base-catalyzed rearrangements of bicyclic endoperoxides having electron-withdrawing substituent...
Scheme 77: The base-catalyzed rearrangements of bicyclic endoperoxides 249a,b having electron-donating substit...
Scheme 78: The base-catalyzed rearrangements of bridge-head substituted bicyclic endoperoxides 251a,b.
Scheme 79: The Kornblum–DeLaMare rearrangement of hydroperoxide 253.
Scheme 80: Synthesis of β-hydroxy hydroperoxide 254 from endoperoxide 253.
Scheme 81: The amine-catalyzed rearrangement of bicyclic endoperoxide 263.
Scheme 82: The base-catalyzed rearrangement of meso-endoperoxide 268 into 269.
Scheme 83: The photooxidation of 271 and subsequent Kornblum–DeLaMare reaction.
Scheme 84: The Kornblum–DeLaMare rearrangement as one step in the oxidation reaction of enamines.
Scheme 85: The Kornblum–DeLaMare rearrangement of 3,5-dihydro-1,2-dioxenes 284, 1,2-dioxanes 286, and tert-but...
Scheme 86: The Kornblum–DeLaMare rearrangement of epoxy dioxanes 290a–d.
Scheme 87: Rearrangement of prostaglandin H2 292.
Scheme 88: The synthesis of epicoccin G (297).
Scheme 89: The Kornblum–DeLaMare rearrangement used in the synthesis of phomactin A.
Scheme 90: The Kornblum–DeLaMare rearrangement in the synthesis of 3H-quinazolin-4-one 303.
Scheme 91: The Kornblum–DeLaMare rearrangement in the synthesis of dolabriferol (308).
Scheme 92: Sequential transformation of 3-substituted 2-pyridones 309 into 3-hydroxypyridine-2,6-diones 311 in...
Scheme 93: The Kornblum–DeLaMare rearrangement of peroxide 312 into hydroxy enone 313.
Scheme 94: The Kornblum–DeLaMare rearrangement in the synthesis of polyfunctionalized carbonyl compounds 317.
Scheme 95: The Kornblum–DeLaMare rearrangement in the synthesis of (Z)-β-perfluoroalkylenaminones 320.
Scheme 96: The Kornblum–DeLaMare rearrangement in the synthesis of γ-ketoester 322.
Scheme 97: The Kornblum–DeLaMare rearrangement in the synthesis of diterpenoids 326 and 328.
Scheme 98: The synthesis of natural products hainanolidol (331) and harringtonolide (332) from peroxide 329.
Scheme 99: The synthesis of trans-fused butyrolactones 339 and 340.
Scheme 100: The synthesis of leucosceptroid C (343) and leucosceptroid P (344) via the Kornblum–DeLaMare rearra...
Scheme 101: The Dakin oxidation of arylaldehydes or acetophenones.
Scheme 102: The mechanism of the Dakin oxidation.
Scheme 103: A solvent-free Dakin reaction of aromatic aldehydes 356.
Scheme 104: The organocatalytic Dakin oxidation of electron-rich arylaldehydes 358.
Scheme 105: The Dakin oxidation of electron-rich arylaldehydes 361.
Scheme 106: The Dakin oxidation of arylaldehydes 358 in water extract of banana (WEB).
Scheme 107: A one-pot approach towards indolo[2,1-b]quinazolines 364 from indole-3-carbaldehydes 363 through th...
Scheme 108: The synthesis of phenols 367a–c from benzaldehydes 366a-c via acid-catalyzed Dakin oxidation.
Scheme 109: Possible transformation paths of the highly polarized boric acid coordinated H2O2–aldehyde adduct 3...
Scheme 110: The Elbs oxidation of phenols 375 to hydroquinones.
Scheme 111: The mechanism of the Elbs persulfate oxidation of phenols 375 affording p-hydroquinones 376.
Scheme 112: Oxidation of 2-pyridones 380 under Elbs persulfate oxidation conditions.
Scheme 113: Synthesis of 3-hydroxy-4-pyridone (384) via an Elbs oxidation of 4-pyridone (382).
Scheme 114: The Schenck rearrangement.
Scheme 115: The Smith rearrangement.
Scheme 116: Three main pathways of the Schenck rearrangement.
Scheme 117: The isomerization of hydroperoxides 388 and 389.
Scheme 118: Trapping of dioxacyclopentyl radical 392 by oxygen.
Scheme 119: The hypothetical mechanism of the Schenck rearrangement of peroxide 394.
Scheme 120: The autoxidation of oleic acid (397) with the use of labeled isotope 18O2.
Scheme 121: The rearrangement of 18O-labeled hydroperoxide 400 under an atmosphere of 16O2.
Scheme 122: The rearrangement of the oleate-derived allylic hydroperoxides (S)-421 and (R)-425.
Scheme 123: Mechanisms of Schenck and Smith rearrangements.
Scheme 124: The rearrangement and cyclization of 433.
Scheme 125: The Wieland rearrangement.
Scheme 126: The rearrangement of bis(triphenylsilyl) 439 or bis(triphenylgermyl) 441 peroxides.
Scheme 127: The oxidative transformation of cyclic ketones.
Scheme 128: The hydroxylation of cyclohexene (447) in the presence of tungstic acid.
Scheme 129: The oxidation of cyclohexene (447) under the action of hydrogen peroxide.
Scheme 130: The reaction of butenylacetylacetone 455 with hydrogen peroxide.
Scheme 131: The oxidation of bridged 1,2,4,5-tetraoxanes.
Scheme 132: The proposed mechanism for the oxidation of bridged 1,2,4,5-tetraoxanes.
Scheme 133: The rearrangement of ozonides.
Scheme 134: The acid-catalyzed oxidative rearrangement of malondialdehydes 462 under the action of H2O2.
Scheme 135: Pathways of the Lewis acid-catalyzed cleavage of dialkyl peroxides 465 and ozonides 466.
Scheme 136: The mechanism of the transformation of (tert-butyldioxy)cyclohexanedienones 472.
Scheme 137: The synthesis of Vitamin K3 from 472a.
Scheme 138: Proposed mechanism for the transformation of 478d into silylated endoperoxide 479d.
Scheme 139: The rearrangement of hydroperoxide 485 to form diketone 486.
Scheme 140: The base-catalyzed rearrangement of cyclic peroxides 488a–g.
Scheme 141: Synthesis of chiral epoxides and aldols from peroxy hemiketals 491.
Scheme 142: The multistep transformation of (R)-carvone (494) to endoperoxides 496a–e.
Scheme 143: The decomposition of anthracene endoperoxide 499.
Scheme 144: Synthesis of esters 503 from aldehydes 501 via rearrangement of peroxides 502.
Scheme 145: Two possible paths for the base-promoted decomposition of α-azidoperoxides 502.
Scheme 146: The Story decomposition of cyclic diperoxide 506a.
Scheme 147: The Story decomposition of cyclic triperoxide 506b.
Scheme 148: The thermal rearrangement of endoperoxides A into diepoxides B.
Scheme 149: The transformation of peroxide 510 in the synthesis of stemolide (511).
Scheme 150: The possible mechanism of the rearrangement of endoperoxide 261g.
Scheme 151: The photooxidation of indene 517.
Scheme 152: The isomerization of ascaridole (523).
Scheme 153: The isomerization of peroxide 525.
Scheme 154: The thermal transformation of endoperoxide 355.
Scheme 155: The photooxidation of cyclopentadiene (529) at a temperature higher than 0 °C.
Scheme 156: The thermal rearrangement of endoperoxides 538a,b.
Scheme 157: The transformation of peroxides 541.
Scheme 158: The thermal rearrangements of strained cyclic peroxides.
Scheme 159: The thermal rearrangement of diacyl peroxide 551 in the synthesis of C4-epi-lomaiviticin B core 553....
Scheme 160: The 1O2 oxidation of tryptophan (554) and rearrangement of dioxetane intermediate 555.
Scheme 161: The Fe(II)-promoted cleavage of aryl-substituted bicyclic peroxides.
Scheme 162: The proposed mechanism of the Fe(II)-promoted rearrangement of 557a–c.
Scheme 163: The reaction of dioxolane 563 with Fe(II) sulfate.
Scheme 164: Fe(II)-promoted rearrangement of 1,2-dioxane 565.
Scheme 165: Fe(II) cysteinate-promoted rearrangement of 1,2-dioxolane 568.
Scheme 166: The transformation of 1,2-dioxanes 572a–c under the action of FeCl2.
Scheme 167: Fe(II) cysteinate-promoted transformation of tetraoxane 574.
Scheme 168: The CoTPP-catalyzed transformation of bicyclic endoperoxides 600a–d.
Scheme 169: The CoTPP-catalyzed transformation of epoxy-1,2-dioxanes.
Scheme 170: The Ru(II)-catalyzed reactions of 1,4-endoperoxide 261g.
Scheme 171: The Ru(II)-catalyzed transformation as a key step in the synthesis of elyiapyrone A (610) from 1,4-...
Scheme 172: Peroxides with antimalarial activity.
Scheme 173: The interaction of iron ions with artemisinin (616).
Scheme 174: The interaction of FeCl2 with 1,2-dioxanes 623, 624.
Scheme 175: The mechanism of reaction 623 and 624 with Fe(II)Cl2.
Scheme 176: The reaction of bicyclic natural endoperoxides G3-factors 631–633 with FeSO4.
Scheme 177: The transformation of terpene cardamom peroxide 639.
Scheme 178: The different ways of the cleavage of tetraoxane 643.
Scheme 179: The LC–MS analysis of interaction of tetraoxane 646 with iron(II)heme 647.
Scheme 180: The rearrangement of 3,6-epidioxy-1,10-bisaboladiene (EDBD, 649).
Scheme 181: Easily oxidized substrates.
Scheme 182: Biopathway of synthesis of prostaglandins.
Scheme 183: The reduction and rearrangements of isoprostanes.
Scheme 184: The partial mechanism for linoleate 658 oxidation.
Scheme 185: The transformation of lipid hydroperoxide.
Scheme 186: The acid-catalyzed cleavage of the product from free-radical oxidation of cholesterol (667).
Scheme 187: Two pathways of catechols oxidation.
Scheme 188: Criegee-like or Hock-like rearrangement of the intermediate hydroperoxide 675 in dioxygenase enzyme...
Scheme 189: Carotinoides 679 cleavage by carotenoid cleavage dioxygenases.
Biosynthesis of oxygen and nitrogen-containing heterocycles in polyketides
- Franziska Hemmerling and
- Frank Hahn
Beilstein J. Org. Chem. 2016, 12, 1512–1550, doi:10.3762/bjoc.12.148
- consumption of hydrogen peroxide. It has been shown that the AS is substrate tolerant and accepts different hydroxylation patterns as well as glycosylations on the chalcone A and B rings [154]. However, the oxidative half-reaction only occurs with chalcones and not with other aryl substrates like L-tyrosine
Graphical Abstract
Scheme 1: Schematic description of the cyclisation reaction catalysed by TE domains. In most cases, the nucle...
Scheme 2: Mechanisms for the formation of oxygen heterocycles. The degree of substitution can differ from tha...
Scheme 3: Pyran-ring formation in pederin (24) biosynthesis. Incubation of recombinant PedPS7 with substrate ...
Scheme 4: The domain AmbDH3 from ambruticin biosynthesis catalyses the dehydration of 25 and subsequent cycli...
Scheme 5: SalBIII catalyses dehydration of 29 and subsequent cyclisation to tetrahydropyran 30 [18].
Figure 1: All pyranonaphtoquinones contain either the naphtha[2,3-c]pyran-5,10-dione (32) or the regioisomeri...
Scheme 6: Pyran-ring formation in actinorhodin (34) biosynthesis. DNPA: 4-dihydro-9-hydroxy-1-methyl-10-oxo-3H...
Scheme 7: Pyran formation in granaticin (36) biosynthesis. DNPA: 4-dihydro-9-hydroxy-1-methyl-10-oxo-3H-napht...
Scheme 8: Pyran formation in alnumycin (37) biosynthesis. Adapted from [21].
Scheme 9: Biosynthesis of pseudomonic acid A (61). The pyran ring is initially formed in 57 after dehydrogena...
Scheme 10: Epoxidation–cyclisation leads to the formation of the tetrahydropyran ring in the western part of t...
Scheme 11: a) Nonactin (70) is formed from heterodimers of (−)(+)-dimeric nonactic acid and (+)(−)-dimeric non...
Figure 2: Pamamycins (73) are macrodiolide antibiotics containing three tetrahydrofuran moieties, which are a...
Scheme 12: A PS domain homolog in oocydin A (76) biosynthesis is proposed to catalyse furan formation via an o...
Scheme 13: Mechanism of oxidation–furan cyclisation by AurH, which converts (+)-deoxyaureothin (77) into (+)-a...
Scheme 14: Leupyrrin A2 (80) and the proposed biosynthesis of its furylidene moiety [69,70].
Scheme 15: Asperfuranone (93) biosynthesis, adapted from [75].
Figure 3: The four major aflatoxins produced by Aspergilli are the types B1, B2, G1 and G2 (94–97). In the di...
Scheme 16: Overview on aflatoxin B1 (94) biosynthesis. HOMST = 11-hydroxy-O-methylsterigmatocystin [78,79,82-106].
Scheme 17: A zipper mechanism leads to the formation of oxygen heterocycles in monensin biosynthesis [109-111].
Scheme 18: Formation of the 2,6-dioxabicyclo[3.2.1]octane (DBO) ring system in aurovertin B (118) biosynthesis ...
Figure 4: Structures of the epoxide-containing polyketides epothilone A (119) and oleandomycin (120) [123-125].
Scheme 19: Structures of phoslactomycin B (121) (a) and jerangolid A (122) (b). The heterocycle-forming steps ...
Scheme 20: a) Structures of rhizoxin (130) and cycloheximide (131). Model for the formation of δ-lactones (b) ...
Scheme 21: EncM catalyses a dual oxidation sequence and following processing of the highly reactive intermedia...
Figure 5: Mesomeric structures of tetronates [138,139].
Figure 6: Structures of tetronates for which gene clusters have been sequenced. The tetronate moiety is shown...
Scheme 22: Conserved steps for formation and processing in several 3-acyl-tetronate biosynthetic pathways were...
Scheme 23: In versipelostatin A (153) biosynthesis, VstJ is a candidate enzyme for catalysing the [4 + 2] cycl...
Scheme 24: a) Structures of some thiotetronate antibiotics. b) Biosynthesis of thiolactomycin (165) as propose...
Scheme 25: Aureusidine synthase (AS) catalyses phenolic oxidation and conjugate addition of chalcones leading ...
Scheme 26: a) Oxidative cyclisation is a key step in the biosynthesis of spirobenzofuranes 189, 192 and 193. b...
Scheme 27: A bicyclisation mechanism forms a β-lactone and a pyrrolidinone and removes the precursor from the ...
Scheme 28: Spontaneous cyclisation leads to off-loading of ebelactone A (201) from the PKS machinery [163].
Scheme 29: Mechanisms for the formation of nitrogen heterocycles.
Scheme 30: Biosynthesis of highly substituted α-pyridinones. a) Feeding experiments confirmed the polyketide o...
Scheme 31: Acridone synthase (ACS) catalyses the formation of 1,3-dihydroxy-N-methylacridone (224) by condensa...
Scheme 32: A Dieckmann condensation leads to the formation of a 3-acyl-4-hydroxypyridin-2-one 227 and removes ...
Scheme 33: a) Biosynthesis of the pyridinone tenellin (234). b) A radical mechanism was proposed for the ring-...
Scheme 34: a) Oxazole-containing PKS–NRPS-derived natural products oxazolomycin (244) and conglobatin (245). b...
Scheme 35: Structure of tetramic acids 251 (a) and major tautomers of 3-acyltetramic acids 252a–d (b). Adapted...
Scheme 36: Equisetin biosynthesis. R*: terminal reductive domain. Adapted from [202].
Scheme 37: a) Polyketides for which a similar biosynthetic logic was suggested. b) Pseurotin A (256) biosynthe...
Figure 7: Representative examples of PTMs with varying ring sizes and oxidation patterns [205,206].
Scheme 38: Ikarugamycin biosynthesis. Adapted from [209-211].
Scheme 39: Tetramate formation in pyrroindomycin aglycone (279) biosynthesis [213-215].
Scheme 40: Dieckmann cyclases catalyse tetramate or 2-pyridone formation in the biosynthesis of, for example, ...
Automated glycan assembly of a S. pneumoniae serotype 3 CPS antigen
- Markus W. Weishaupt,
- Stefan Matthies,
- Mattan Hurevich,
- Claney L. Pereira,
- Heung Sik Hahm and
- Peter H. Seeberger
Beilstein J. Org. Chem. 2016, 12, 1440–1446, doi:10.3762/bjoc.12.139
- using a mixture of lithium hydroxide and hydrogen peroxide to avoid elimination reactions which are common for uronic acid methyl esters under strongly basic conditions [30][32]. In the next step, the remaining esters were removed employing sodium hydroxide in methanol. Finally, catalytic hydrogenation
Graphical Abstract
Figure 1: Disaccharide repeating unit of the S. pneumoniae serotype 3 CPS.
Figure 2: Building blocks and solid support for the automated solid-phase synthesis of S. pneumoniae serotype...
Scheme 1: Attempted assembly of SP3 trisaccharide 5 using glycosyl phosphate building blocks 1 and 2. Reagent...
Figure 3: HPLC chromatogram of the crude products of the attempted AGA of SP3 trisaccharide 5; conditions: YM...
Scheme 2: Attempted AGA of SP3 trisaccharide 9 using glycosyl phosphate building blocks 1 and 3. Reagents and...
Figure 4: HPLC chromatogram of the crude products of the attempted AGA of SP3 trisaccharide 9; conditions: YM...
Scheme 3: Automated synthesis of linker-bound glucuronic acid 10 using glycosyl phosphate building block 1. R...
Scheme 4: Automated synthesis of SP3 trisaccharide 5 using glycosyl phosphate building blocks 1 and 2. Reagen...
Figure 5: HPLC chromatogram of the crude products of the automated solid-phase SP3 trisaccharide 5 synthesis;...
Scheme 5: Global deprotection of SP3 trisaccharide 5. Reagents and conditions: a) LiOH, H2O2, THF, −5 °C to r...
Interactions between 4-thiothymidine and water-soluble cyclodextrins: Evidence for supramolecular structures in aqueous solutions
- Vito Rizzi,
- Sergio Matera,
- Paola Semeraro,
- Paola Fini and
- Pinalysa Cosma
Beilstein J. Org. Chem. 2016, 12, 549–563, doi:10.3762/bjoc.12.54
- , ROS (namely singlet oxygen, superoxide ions and hydrogen peroxide), generated via the excited state of the PS, destroy the PS itself. Because of this, the effort to preserve the PS is one of main issues. Regarding S4TdR, as a result of its photodynamic activity, the thiobase can be destroyed by a
Graphical Abstract
Figure 1: Molecular structure of S4TdR. H atoms are also labeled in the Figure.
Figure 2: Comparison between UV–vis absorption spectra (detailed view: 280–380 nm) obtained for 1 × 10−5 M aq...
Figure 3: Cyclic voltammetry of aqueous solutions containing S4TdR (black solid line) in presence of increasi...
Figure 4: (A) Plot of cathodic potential values and (B) of the corresponding current intensity, obtained for S...
Figure 5: Comparison between detailed views (frequency range: 4000–600 cm−1) of the FTIR–ATR spectra obtained...
Figure 6: Modified Benesi–Hildebrand plot of [H]/[G]/Δδ versus [H]/[G] in the presence of S4TdR at an initial...
Aluminacyclopentanes in the synthesis of 3-substituted phospholanes and α,ω-bisphospholanes
- Vladimir A. D’yakonov,
- Alevtina L. Makhamatkhanova,
- Rina A. Agliullina,
- Leisan K. Dilmukhametova,
- Tat’yana V. Tyumkina and
- Usein M. Dzhemilev
Beilstein J. Org. Chem. 2016, 12, 406–412, doi:10.3762/bjoc.12.43
- dichlorophosphines (R′PCl2). Hydrogen peroxide oxidation and treatment with S8 of the synthesized phospholanes and α,ω-bisphospholanes afforded the corresponding 3-alkyl(aryl)-1-alkyl(phenyl)phospholane 1-oxides, 3-alkyl(aryl)-1-alkyl(phenyl)phospholane 1-sulfides, bisphospholane 1,1'-dioxides, and bisphospholane
- regioisomers react in situ with phosphorus dihalides and hydrogen peroxide to afford 1-phenyl(alkyl)-2-arylphospholane oxides 7a–f and 1-phenyl(alkyl)-3-arylphospholane oxides 8a–f in 2:1 ratio in a 69–87% total yield (Table 2). The regioisomers were isolated by column chromatography (hexane/ethyl acetate
- ]+): 277.4046; found: 277.4. Preparation of 3-alkyl(aryl)phospholane-1-oxides (general procedure) A 30% solution of hydrogen peroxide (0.7 mL, 6 mmol) was slowly added dropwise with vigorous stirring to a solution of 3-alkyl(benzyl)-1-alkyl(phenyl)phospholane (5 mmol), synthesized as described above, in
Graphical Abstract
Scheme 1: Synthesis of 3-substituted phospholanes according to earlier data [14-17].
Scheme 2: Synthesis of 3-substituted phospholanes.
Scheme 3: Synthesis of 3-substituted phospholane oxides and sulfides.
Scheme 4: Synthesis of 3-substituted 7a–f and 2-substituted 8a–f phospholanes.
Scheme 5: Synthesis of bisphospholanes.
Scheme 6: Synthesis of bisphospholane-1,1'-oxides and bisphospholane-1,1'-sulfides.
Scheme 7: Synthesis of the molybdenum complex (3-hexyl(benzyl)-1-phenyl(methyl)phospholane)Mo(CO)5.
Scheme 8: Synthesis of molybdenum complexes (1,2(1,6)-bis(1-phenylphospholan-3-yl)ethane(hexane))Mo(CO)5.
Synthesis and reactivity of aliphatic sulfur pentafluorides from substituted (pentafluorosulfanyl)benzenes
- Norbert Vida,
- Jiří Václavík and
- Petr Beier
Beilstein J. Org. Chem. 2016, 12, 110–116, doi:10.3762/bjoc.12.12
- the Czech Republic, Vídeňská 1083, 142 20 Prague, Czech Republic 10.3762/bjoc.12.12 Abstract Oxidation of 3- and 4-pentafluorosulfanyl-substituted anisoles and phenols with hydrogen peroxide and sulfuric acid provided a mixture of SF5-substituted muconolactone, maleic, and succinic acids. A plausible
- -(pentafluorosulfanyl)anisole (1) or 4-(pentafluorosulfanyl)phenol (2) by a mixture of aqueous hydrogen peroxide and concentrated sulfuric acid (Scheme 1). The major product was muconolactone 3 while maleic acid 4 and succinic acid 5 were formed in small amounts. Herein we report a full account of this oxidation
- )anisole and 4-(pentafluorosulfanyl)phenol the meta-derivatives 10 and 11 underwent oxidation with aqueous hydrogen peroxide in sulfuric acid to provide SF5-muconolactone and SF5-maleic acid as main products. Improved conversion of SF5-maleic acid was rationalized by preferential formation of SF5
Graphical Abstract
Scheme 1: Oxidation of SF5-anisole and phenol. 19F NMR yields are shown (isolated yields in parentheses).
Scheme 2: Proposed mechanism for the formation of 3 and 4 from SF5 aromatics 1 and 2.
Scheme 3: Oxidation of anisole 10 and phenol 11. 19F NMR yields are given.
Scheme 4: Synthesis of para-benzoquinone 12 and oxidation to maleic acid 4. 19F NMR yields are shown, in pare...
Scheme 5: Catalytic hydrogenation and Diels–Alder reaction of benzoquinone 12.
Figure 1: Optimized geometries of transition states of Diels–Alder reaction of cyclopentadiene with 12. Selec...
Scheme 6: Decomposition of 3 in water.
Scheme 7: Formation of acids 5, 18 and 19 from lactone 3.
Scheme 8: Synthesis of maleic anhydride 20 and Diels–Alder adducts 21.
Scheme 9: Reaction of maleic acid 4 with diazomethane.
Scheme 10: Decarboxylation of maleic acid 4 to acrylic acid 23 in DMSO and the preparation of deuterium labell...
Supramolecular polymer assembly in aqueous solution arising from cyclodextrin host–guest complexation
- Jie Wang,
- Zhiqiang Qiu,
- Yiming Wang,
- Li Li,
- Xuhong Guo,
- Duc-Truc Pham,
- Stephen F. Lincoln and
- Robert K. Prud’homme
Beilstein J. Org. Chem. 2016, 12, 50–72, doi:10.3762/bjoc.12.7
- greatly deceased upon the addition of β-CD because host–guest complexation of ferrocene masks its hydrophobicity and the hydrophilic exterior of the complexing β-CD much decreases association between the polymer chains. The same effect occurs when hydrogen peroxide is added to aqueous BPEI-FC and the
Graphical Abstract
Figure 1: Structures of α-, β- and γ-CD. Individual carbon atom numbering is shown for one D-glucopyranose su...
Figure 2: Associations of hydrophobic substituents (circled) (a) and their disruption through host–guest comp...
Figure 3: Decrease of aqueous solution viscosity at a shear rate of 50 s−1 due to α-CD (circles), β-CD (recta...
Figure 4: The effect of (a) α-CD, (b) β-CD and (c) γ-CD on the hydrophobic interactions between n-C18H37 subs...
Figure 5: The effect of SDS addition on viscosity shear rate dependence for 2 wt % aqueous PAAodn solutions c...
Figure 6: Host–guest complexation between polymers with cyclodextrin and hydrophobic substituents.
Figure 7: Variation of viscosity with mole ratio of CD substituents to hydrophobic substituents on poly(acryl...
Figure 8: Illustration of the competitive intermolecular host–guest complexation of either the adamantyl subs...
Figure 9: Competitive host–guest complexations in which either the adamantyl substituent (red) or the n-hexyl...
Figure 10: (a) Substituted chitosan in which acyl- and adamantyl-substitution is 5% and 12 %, respectively. (b...
Figure 11: The formation of a AD-PEG micelle followed by the formation of a AD-PEG/α-CD supramolecular hydroge...
Figure 12: Interaction of PEG-b-PAA block copolymer with cis-diamminedichloroplatinum(II), cisplatin, to form ...
Figure 13: Solution to hydrogel transitions (a)–(d) for a PAAddn segment in the presence of competitive photo-...
Figure 14: Structures of the poly(acrylate)-based polymers PAAAzo (trans), PAAAzo (cis), PAA3α-CD and PAA6α-CD...
Figure 15: Variation of viscosity of a PAA6α-CD/PAAAzo solution (circles) and a PAA3α-CD/PAAAzo solution (tria...
Figure 16: The structures proposed for the poly(ethylene glycol)-b-poly(ethylamine)-g-dextran·γ-CD, PEG-PEI-de...
Figure 17: Structure of poly(ethylene glycol) polyrotaxane with adamantyl end substituents, and its temperatur...
Figure 18: Copolymers of either (a) N,N-dimethylacrylamide (DMAA) or (b) N-isopropylacrylamine (NIPAAM) with 1...
Figure 19: The copolymer of isopropylacrylamine and methacrylated β-CD (a) and its complexation of the anions ...
Figure 20: Solution to hydrogel transitions for two segments of PAAddn in the presence of β-CD and change in t...
Figure 21: Preparation of a β-CD and adamantyl substituted acrylamide polymer hydrogel involving host–guest co...
Figure 22: Aqueous solutions of the polymers poly-β-CD and poly-α-BrNP form the poly-β-CD/poly-α-BrNP hydrogel ...
Figure 23: (a) Randomly β-CD substituted poly(acrylate), PAA-6β-CD. (b) Randomly ferrocenyl substituted poly(a...
Figure 24: (a) The β-CD, adamantyl and ferrocenyl substituted pAAm and pNiPAAM polymers. (b) The β-CD, adamant...
Iron complexes of tetramine ligands catalyse allylic hydroxyamination via a nitroso–ene mechanism
- David Porter,
- Belinda M.-L. Poon and
- Peter J. Rutledge
Beilstein J. Org. Chem. 2015, 11, 2549–2556, doi:10.3762/bjoc.11.275
- 5. Nicholas and Kalita have reported that the addition of hydrogen peroxide can improve yields in their copper-catalysed allylic amination reactions using BocNHOH [41]. Thus the addition of hydrogen peroxide (1:1 relative to BocNHOH) to reactions with 4 or 5 was investigated. Using a 1:1:1 ratio of
- cyclohexene:BocNHOH:H2O2 with FeTPA (4) at 1 mol %, allylic hydroxylamine 9 was formed in only 4% yield, with the allylic oxidation products 9 and 10 predominant. This is not unexpected given the propensity of hydrogen peroxide to react directly with iron complexes to produce 10 and 11 via Fenton-type pathways [47][53
Graphical Abstract
Figure 1: TPA (1), BPMEN (2) and (R,R′)-PDP (3) ligands.
Scheme 1: Allylic hydroxyamination of cyclohexene (7) using iron catalysts 4 and 5; i. 4 or 5 (10 mol %), Boc...
Scheme 2: Proposed mechanism for hydroxyamination of cyclohexene (7) by FeTPA (4) and FeBPMEN (5): (a) iron-m...
Scheme 3: Reaction of isoprene (14) under (a) Kirby’s conditions [54,55] and (b) FeTPA- or FeBPMEN-mediated hydoxyam...
Preparative semiconductor photoredox catalysis: An emerging theme in organic synthesis
- David W. Manley and
- John C. Walton
Beilstein J. Org. Chem. 2015, 11, 1570–1582, doi:10.3762/bjoc.11.173
- donor and ‘picks up’ holes thereby releasing a cascade of extremely reactive hydroxyl radicals (see Figure 2). Oxygen acts as the acceptor, picks up electrons from the semiconductor surface, so yielding superoxide anions that are converted to hydroperoxyl radicals and to hydrogen peroxide on successive
Graphical Abstract
Figure 1: Production and utilization of h+ and e– by photoactivation of a semiconductor.
Figure 2: Photoredox activity of TiO2 with moist air.
Scheme 1: TiO2 promoted oxidation of phenanthrene [29].
Scheme 2: SCPC assisted additions of allylic compounds to diazines and imines [40-42].
Scheme 3: TiO2 promoted addition and addition–cyclization reactions of tert-amines with electron-deficient al...
Scheme 4: Reactions of amines promoted by Pt-TiO2 [48,49].
Scheme 5: P25 Promoted alkylations of N-phenylmaleimide with diverse carboxylic acids [53,54]. aAccompanied by R–R d...
Scheme 6: SCPC cyclizations of aryloxyacetic acids with suitably sited alkene acceptors [54]. aYields in brackets...
Scheme 7: TiO2 promoted reactions of aryloxyacetic acids with maleic anhydride and maleimides [53,54].
Scheme 8: Photoredox addition–cyclization reactions of aryloxyacetic and related acids promoted by maleimide [63]....
Scheme 9: SCPC promoted homo-couplings and macrocyclizations with carboxylic acids [64].
Scheme 10: TiO2 promoted alkylations of alkenes with silanes [66] and thiols [67].
Scheme 11: TiO2 reduction of a nitrochromenone derivative [70].
Scheme 12: TiO2 mediated hydrodehalogenations and cyclizations of organic iodides [71].
Scheme 13: TiO2 promoted hydrogenations of maleimides, maleic anhydride and aromatic aldehydes [79].
Scheme 14: Mechanistic sketch of SCPC hydrogenation of aryl aldehydes.
Selected synthetic strategies to cyclophanes
- Sambasivarao Kotha,
- Mukesh E. Shirbhate and
- Gopalkrushna T. Waghule
Beilstein J. Org. Chem. 2015, 11, 1274–1331, doi:10.3762/bjoc.11.142
Graphical Abstract
Figure 1: General representation of cyclophanes.
Figure 2: cyclophanes one or more with heteroatom.
Figure 3: Metathesis catalysts 12–17 and C–C coupling catalyst 18.
Figure 4: Natural products containing the cyclophane skeleton.
Figure 5: Turriane family of natural products.
Scheme 1: Synthesis of [3]ferrocenophanes through Mannich reaction. Reagents and conditions: (i) excess HNMe2...
Scheme 2: Synthesis of cyclophanes through Michael addition. Reagents and conditions: (i) xylylene dibromide,...
Scheme 3: Synthesis of normuscopyridine analogue 37 through an oxymercuration–oxidation strategy. Reagents an...
Scheme 4: Synthesis of tribenzocyclotriyne 39 through Castro–Stephens coupling reaction. Reagents and conditi...
Scheme 5: Synthesis of cyclophane 43 through Glaser–Eglinton coupling. Reagents and conditions: (i) 9,10-bis(...
Scheme 6: Synthesis of the macrocyclic C-glycosyl cyclophane through Glaser coupling. Reagents and conditions...
Scheme 7: Synthesis of cyclophane-containing complex 49 through Glaser–Eglinton coupling reaction. Reagents a...
Scheme 8: Synthesis of cyclophane 53 through Glaser–Eglinton coupling. Reagents and conditions: (i) K2CO3, ac...
Figure 6: Cyclophanes 54–56 that have been synthesized through Glaser–Eglinton coupling.
Figure 7: Synthesis of tetrasubstituted [2.2]paracyclophane 57 and chiral cyclophyne 58 through Eglinton coup...
Scheme 9: Synthesis of cyclophane through Glaser–Hay coupling reaction. Reagents and conditions: (i) CuCl2 (1...
Scheme 10: Synthesis of seco-C/D ring analogs of ergot alkaloids through intramolecular Heck reaction. Reagent...
Scheme 11: Synthesis of muscopyridine 73 via Kumada coupling. Reagents and conditions: (i) 72, THF, ether, 20 ...
Scheme 12: Synthesis of the cyclophane 79 via McMurry coupling. Reagents and conditions: (i) 75, decaline, ref...
Scheme 13: Synthesis of stilbenophane 81 via McMurry coupling. Reagents and conditions: (i) TiCl4, Zn, pyridin...
Scheme 14: Synthesis of stilbenophane 85 via McMurry coupling. Reagents and conditions: (i) NBS (2 equiv), ben...
Figure 8: List of cyclophanes prepared via McMurry coupling reaction as a key step.
Scheme 15: Synthesis of paracyclophane by cross coupling involving Pd(0) catalyst. Reagents and conditions: (i...
Scheme 16: Synthesis of the cyclophane 112 via the pinacol coupling and 113 by RCM. Reagents and conditions: (...
Scheme 17: Synthesis of cyclophane derivatives 122a–c via Sonogoshira coupling. Reagents and conditions: (i) C...
Scheme 18: Synthesis of cyclophane 130 via Suzuki–Miyaura reaction as a key step. Reagents and conditions: (i)...
Scheme 19: Synthesis of the mycocyclosin via Suzuki–Miyaura cross coupling. Reagents and conditions: (i) benzy...
Scheme 20: Synthesis of cyclophanes via Wurtz coupling reaction Reagents and conditions: (i) PhLi, Et2O, C6H6,...
Scheme 21: Synthesis of non-natural glycophanes using alkyne metathesis. Reagents and conditions: (i) G-I (12)...
Figure 9: Synthesis of cyclophanes via ring-closing alkyne metathesis.
Scheme 22: Synthesis of crownophanes by cross-enyne metathesis. Reagents and conditions: (i) G-II (13), 5 mol ...
Scheme 23: Synthesis of (−)-cylindrocyclophanes A (156) and (−)-cylindrocyclophanes F (155). Reagents and cond...
Scheme 24: Synthesis of cyclophane 159 derivatives via SM cross-coupling and RCM. Reagents and conditions: (i)...
Scheme 25: Sexithiophene synthesis via cross metathesis. Reagents and conditions: (i) 161, Pd(PPh3)4, K2CO3, T...
Scheme 26: Synthesis of pyrrole-based cyclophane using enyne metathesis. Reagents and conditions: (i) Se, chlo...
Scheme 27: Synthesis of macrocyclic derivatives by RCM. Reagents and conditions: (i) G-I/G-II, CH2Cl2, 0.005 M...
Scheme 28: Synthesis of enantiopure β-lactam-based dienyl bis(dihydrofuran) 179. Reagents and conditions: (i) ...
Scheme 29: Synthesis of a [1.1.6]metaparacyclophane derivative 183 via SM cross coupling. Reagents and conditi...
Scheme 30: Synthesis of a [1.1.6]metaparacyclophane derivative 190 via SM cross coupling. Reagents and conditi...
Scheme 31: Template-promoted synthesis of cyclophanes involving RCM. Reagents and conditions: (i) acenaphthene...
Scheme 32: Synthesis of [3.4]cyclophane derivatives 200 via SM cross coupling and RCM. Reagents and conditions...
Figure 10: Examples for cyclophanes synthesized by RCM.
Scheme 33: Synthesis of the longithorone C framework assisted by fluorinated auxiliaries. Reagents and conditi...
Scheme 34: Synthesis of the longithorone framework via RCM. Reagents and conditions: (i) 213, NaH, THF, rt, 10...
Scheme 35: Synthesis of floresolide B via RCM as a key step. Reagents and conditions: (i) G-II (13, 0.1 equiv)...
Scheme 36: Synthesis of normuscopyridine (223) by the RCM strategy. Reagents and condition: (i) Mg, THF, hexen...
Scheme 37: Synthesis of muscopyridine (73) via RCM. Reagents and conditions: (i) 225, NaH, THF, 0 °C to rt, 1....
Scheme 38: Synthesis of muscopyridine (73) via RCM strategy. Reagents and conditions: (i) NaH, n-BuLi, 5-bromo...
Scheme 39: Synthesis of pyridinophane derivatives 223 and 245. Reagents and conditions: (i) PhSO2Na, TBAB, CH3...
Scheme 40: Synthesis of metacyclophane derivatives 251 and 253. Reagents and conditions: (i) 240, NaH, THF, rt...
Scheme 41: Synthesis of normuscopyridine and its higher analogues. Reagents and conditions: (i) alkenyl bromid...
Scheme 42: Synthesis of fluorinated ferrocenophane 263 via a [2 + 2] cycloaddition. Reagents and conditions: (...
Scheme 43: Synthesis of [2.n]metacyclophanes 270 via a [2 + 2] cycloaddition. Reagents and conditions: (i) Ac2...
Scheme 44: Synthesis of metacyclophane 273 by a [2 + 2 + 2] co-trimerization. Reagents and conditions: (i) [Rh...
Scheme 45: Synthesis of paracyclophane 276 via a [2 + 2 + 2] cycloaddition reaction. Reagents and conditions: ...
Scheme 46: Synthesis of cyclophane 278 via a [2 + 2 + 2] cycloaddition reaction. Reagents and conditions: (i) ...
Scheme 47: Synthesis of cyclophane 280 via a [2 + 2 + 2] cycloaddition. Reagents and conditions: (i) [(Rh(cod)(...
Scheme 48: Synthesis of taxane framework by a [2 + 2 + 2] cycloaddition. Reagents and conditions: (i) Cp(CO)2 ...
Scheme 49: Synthesis of cyclophane 284 and 285 via a [2 + 2 + 2] cycloaddition reaction. Reagents and conditio...
Scheme 50: Synthesis of pyridinophanes 293a,b and 294a,b via a [2 + 2 + 2] cycloaddition. Reagents and conditi...
Scheme 51: Synthesis of pyridinophanes 296 and 297 via a [2 + 2 + 2] cycloaddition. Reagents and conditions: (...
Scheme 52: Synthesis of triazolophane by a 1,3-dipolar cycloaddition. Reagents and conditions: (i) propargyl b...
Scheme 53: Synthesis of glycotriazolophane 309 by a click reaction. Reagents and conditions: (i) LiOH, H2O, Me...
Figure 11: Cyclophanes 310 and 311 prepared via click chemistry.
Scheme 54: Synthesis of cyclophane via the Dötz benzannulation. Reagents and conditions: (i) THF, 100 °C, 12 h...
Scheme 55: Synthesis of [6,6]metacyclophane by a Dötz benzannulation. Reagents and conditions: (i) THF, 100 °C...
Scheme 56: Synthesis of cyclophanes by a Dötz benzannulation. Reagents and conditions: (i) THF, 65 °C, 3 h; (i...
Scheme 57: Synthesis of muscopyridine (73) via an intramolecular DA reaction of ketene. Reagents and condition...
Scheme 58: Synthesis of bis[10]paracyclophane 336 via Diels–Alder reaction. Reagents and conditions: (i) DMAD,...
Scheme 59: Synthesis of [8]paracyclophane via DA reaction. Reagents and conditions: (i) maleic anhydride, 3–5 ...
Scheme 60: Biomimetic synthesis of (−)-longithorone A. Reagents and conditions: (i) Me2AlCl, CH2Cl2, −20 °C, 7...
Scheme 61: Synthesis of sporolide B (349) via a [4 + 2] cycloaddition reaction. Reagents and conditions: (i) P...
Scheme 62: Synthesis of the framework of (+)-cavicularin (352) via a [4 + 2] cycloaddition. Reagents and condi...
Scheme 63: Synthesis of oxazole-containing cyclophane 354 via Beckmann rearrangement. Reagents and conditions:...
Scheme 64: Synthesis of cyclophanes 360a–c via benzidine rearrangement. Reagents and conditions: (i) 356a–d, K2...
Scheme 65: Synthesis of cyclophanes 365a–c via benzidine rearrangement. Reagents and conditions: (i) BocNHNH2,...
Scheme 66: Synthesis of metacyclophane 367 via Ciamician–Dennstedt rearrangement. Reagents and conditions: (i)...
Scheme 67: Synthesis of cyclophane by tandem Claisen rearrangement and RCM as key steps. Reagents and conditio...
Scheme 68: Synthesis of cyclophane derivative 380. Reagents and conditions: (i) K2CO3, CH3CN, allyl bromide, r...
Scheme 69: Synthesis of metacyclophane via Cope rearrangement. Reagents and conditions: (i) MeOH, NaBH4, rt, 1...
Scheme 70: Synthesis of cyclopropanophane via Favorskii rearrangement. Reagents and conditions: (i) Br2, CH2Cl2...
Scheme 71: Cyclophane 389 synthesis via photo-Fries rearrangement. Reagents and conditions: (i) DMAP, EDCl/CHCl...
Scheme 72: Synthesis of normuscopyridine (223) via Schmidt rearrangement. Reagents and conditions: (i) ethyl s...
Scheme 73: Synthesis of crownophanes by tandem Claisen rearrangement. Reagents and conditions: (i) diamine, Et3...
Scheme 74: Attempted synthesis of cyclophanes via tandem Claisen rearrangement and RCM. Reagents and condition...
Scheme 75: Synthesis of muscopyridine via alkylation with 2,6-dimethylpyridine anion. Reagents and conditions:...
Scheme 76: Synthesis of cyclophane via Friedel–Craft acylation. Reagents and conditions: (i) CS2, AlCl3, 7 d, ...
Scheme 77: Pyridinophane 418 synthesis via Friedel–Craft acylation. Reagents and conditions: (i) 416, AlCl3, CH...
Scheme 78: Cyclophane synthesis involving the Kotha–Schölkopf reagent 421. Reagents and conditions: (i) NBS, A...
Scheme 79: Cyclophane synthesis involving the Kotha–Schölkopf reagent 421. Reagents and conditions: (i) BEMP, ...
Scheme 80: Cyclophane synthesis by coupling with TosMIC. Reagents and conditions: (i) (a) ClCH2OCH3, TiCl4, CS2...
Scheme 81: Synthesis of diaza[32]cyclophanes and triaza[33]cyclophanes. Reagents and conditions: (i) DMF, NaH,...
Scheme 82: Synthesis of cyclophane 439 via acyloin condensation. Reagents and conditions: (i) Na, xylene, 75%;...
Scheme 83: Synthesis of multibridged binuclear cyclophane 442 by aldol condensation. Reagents and conditions: ...
Scheme 84: Synthesis of various macrolactones. Reagents and conditions: (i) iPr2EtN, DMF, 77–83%; (ii) TBDMSCl...
Scheme 85: Synthesis of muscone and muscopyridine via Yamaguchi esterification. Reagents and conditions: (i) 4...
Scheme 86: Synthesis of [5]metacyclophane via a double elimination reaction. Reagents and conditions: (i) LiBr...
Figure 12: Cyclophanes 466–472 synthesized via Hofmann elimination.
Scheme 87: Synthesis of cryptophane via Baylis–Hillman reaction. Reagents and conditions: (i) methyl acrylate,...
Scheme 88: Synthesis of cyclophane 479 via double Chichibabin reaction. Reagents and conditions: (i) excess 478...
Scheme 89: Synthesis of cyclophane 483 via double Chichibabin reaction. Reagents and conditions: (i) 481, OH−;...
Scheme 90: Synthesis of cyclopeptide via an intramolecular SNAr reaction. Reagents and conditions: (i) TBAF, T...
Scheme 91: Synthesis of muscopyridine (73) via C-zip ring enlargement reaction. Reagents and conditions: (i) H...
Figure 13: Mechanism of the formation of compound 494.
Scheme 92: Synthesis of indolophanetetraynes 501a,b using the Nicholas reaction as a key step. Reagents and co...
Scheme 93: Synthesis of cyclophane via radical cyclization. Reagents and conditions: (i) cyclododecanone, phen...
Scheme 94: Synthesis of (−)-cylindrocyclophanes A (156) and (−)-cylindrocyclophanes F (155). Reagents and cond...
Scheme 95: Cyclophane synthesis via Wittig reaction. Reagents and conditions: (i) LiOEt (2.1 equiv), THF, −78 ...
Figure 14: Representative examples of cyclophanes synthesized via Wittig reaction.
Scheme 96: Synthesis of the [6]paracyclophane via isomerization of Dewar benzene. Reagents and conditions: (i)...
