Recommendations for performing measurements of apparent equilibrium constants of enzyme-catalyzed reactions and for reporting the results of these measurements
- Robert N. Goldberg,
- Robert T. Giessmann,
- Peter J. Halling,
- Carsten Kettner and
- Hans V. Westerhoff
Beilstein J. Org. Chem. 2023, 19, 303–316, doi:10.3762/bjoc.19.26
Synthesis and reactivity of azole-based iodazinium salts
- Thomas J. Kuczmera,
- Annalena Dietz,
- Andreas Boelke and
- Boris J. Nachtsheim
Beilstein J. Org. Chem. 2023, 19, 317–324, doi:10.3762/bjoc.19.27
Graphical Abstract
Figure 1: Nitrogen-containing iodolium and iodonium salts.
Figure 2: Synthesis of a set of azoiodazinium salts 5. Method A: Iodoarene 4 (200 µmol) and mCPBA (1.1 equiv)...
Figure 3: Single crystal structures (ORTEP drawing with 50% probability) of the pyrazole-coordinated salt 5bb...
Scheme 1: Derivatizations of the iodonium salt 5aa. a) Ac2O, CuSO4·5H2O, NaOAc, AcOH, 120 °C, 5 h; b) S8/Se/T...
Scheme 2: Post-functionalization of mono- and dicationic iodonium salts under preservation of the hypervalent...
Group 13 exchange and transborylation in catalysis
- Dominic R. Willcox and
- Stephen P. Thomas
Beilstein J. Org. Chem. 2023, 19, 325–348, doi:10.3762/bjoc.19.28
Graphical Abstract
Scheme 1: Group 13 exchange.
Scheme 2: Borane-catalysed hydroboration of alkynes and the proposed mechanism.
Scheme 3: a) Borane-catalysed hydroboration of alkenes and the proposed mechanism. b) H-B-9-BBN-catalysed dou...
Scheme 4: a) Amine-borane-catalysed C‒H borylation of heterocycles and the proposed mechanism. b) Benzoic aci...
Scheme 5: Bis(pentafluorophenyl)borane-catalysed dimerisation of allenes and the proposed mechanism.
Scheme 6: Alkoxide-promoted hydroboration of heterocycles and the proposed mechanism.
Scheme 7: Borane-catalysed reduction of indoles and the proposed mechanism.
Scheme 8: H-B-9-BBN-catalysed hydrocyanation of enones and the proposed mechanism.
Scheme 9: Borane-catalysed hydroboration of nitriles and the proposed mechanism.
Scheme 10: Myrtanylborane-catalysed asymmetric reduction of propargylic ketones and the proposed mechanism.
Scheme 11: H-B-9-BBN-catalysed C–F esterification of alkyl fluorides and the proposed mechanism.
Scheme 12: H-B-9-BBN-catalysed 1,4-hydroboration of enones and the proposed mechanism.
Scheme 13: Boric acid-promoted reduction of esters, lactones, and carbonates and the proposed mechanism.
Scheme 14: H-B-9-BBN-catalysed reductive aldol-type reaction and the proposed mechanism.
Scheme 15: H-B-9-BBN-catalysed diastereoselective allylation of ketones and the Ph-BBD-catalysed enantioselect...
Scheme 16: H-B-9-BBN-catalysed C–F arylation of benzyl fluorides and the proposed mechanism.
Scheme 17: Borane-catalysed S‒H borylation of thiols and the proposed mechanism.
Scheme 18: Borane-catalysed hydroalumination of alkenes and allenes.
Scheme 19: a) Aluminium-catalysed hydroboration of alkynes and example catalysts. b) Deprotonation mechanistic...
Scheme 20: Aluminium-catalysed hydroboration of alkenes and the proposed mechanism.
Scheme 21: Aluminium-catalysed C–H borylation of terminal alkynes and the proposed mechanism.
Scheme 22: Aluminium-catalysed dehydrocoupling of amines, alcohols, and thiols with H-B-9-BBN or HBpin and the...
Scheme 23: Aluminium-catalysed hydroboration of unsaturated compounds and the general reaction mechanism.
Scheme 24: a) Gallium-catalysed asymmetric hydroboration of ketones and the proposed mechanism. b) Gallium-cat...
Scheme 25: Gallium(I)-catalysed allylation/propargylation of acetals and aminals and the proposed mechanism.
Scheme 26: Indium(I)-catalysed allylation/propargylation of acetals, aminals, and alkyl ethers.
Scheme 27: Iron–indium cocatalysed double hydroboration of nitriles and the proposed mechanism.
Figure 1: a) The number of reports for a given group 13 exchange in catalysis. b) Average free energy barrier...
CuAAC-inspired synthesis of 1,2,3-triazole-bridged porphyrin conjugates: an overview
- Dileep Kumar Singh
Beilstein J. Org. Chem. 2023, 19, 349–379, doi:10.3762/bjoc.19.29
Graphical Abstract
Figure 1: Alkyne–azide "click reaction".
Figure 2: β- and meso-triazole-linked porphyrin.
Scheme 1: Synthesis of β-triazole-linked porphyrins 3a–c.
Scheme 2: Synthesis of β-triazole-bridged porphyrin-coumarin conjugates 11–20.
Scheme 3: Synthesis of β-triazole-bridged porphyrin-xanthone conjugates 23–27 and xanthone-bridged β-triazolo...
Scheme 4: Synthesis of meso-triazoloporphyrins 32a–c and triazole-bridged diporphyrins 34.
Scheme 5: Synthesis of meso-triazole-linked porphyrin-ferrocene conjugates 37a–d.
Scheme 6: Synthesis of meso-triazole-linked porphyrin conjugates 40a,b and 41a,b.
Scheme 7: Synthesis of meso-triazole-linked glycoporphyrins 43a–c.
Scheme 8: Synthesis of meso-triazole-linked porphyrin-coumarin conjugates 44–48.
Scheme 9: Synthesis of meso-triazole-bridged porphyrin-DNA conjugate 50.
Scheme 10: Synthesis of meso-linked porphyrin-triazole conjugates 53 and 57.
Scheme 11: Synthesis of meso-triazole-linked porphyrin-corrole conjugate 60.
Scheme 12: Synthesis of porphyrin conjugates 64a,b and 67a,b. Reaction conditions: (i) CuSO4, sodium ascorbate...
Scheme 13: Synthesis of meso-triazole-bridged porphyrin-quinolone conjugates 70a–e.
Scheme 14: Synthesis of meso-triazole-linked porphyrin-fluorescein dyad 73.
Scheme 15: Synthesis of meso-triazole-linked porphyrin-carborane conjugates 76a,b.
Scheme 16: Synthesis of meso-triazole-bridged porphyrin-BODIPY conjugates 78 and 80.
Scheme 17: Synthesis of meso-triazole-linked cationic porphyrin conjugates 85 and 87. Reaction conditions: (i)...
Scheme 18: Synthesis of meso-triazole-cobalt-porphyrin diimine-dioxime conjugate 91. Reactions conditions: (i)...
Scheme 19: Synthesis of triazole-linked porphyrin-bearing N-doped graphene hybrid 96.
Scheme 20: Synthesis of meso-triazole-linked porphyrin-fullerene dyads 100a–d and 104a,b.
Scheme 21: Synthesis of meso-triazole-bridged diporphyrin conjugates 107 and 108.
Scheme 22: Synthesis of porphyrin-ruthenium (II) conjugates 112a,b and 116a,b. Reaction conditions: (i) Zn(OAc)...
Scheme 23: Synthesis of meso-triazole-linked porphyrin dyad 119 and triad 121.
Scheme 24: Synthesis of di-triazole-bridged porphyrin-β-CD conjugate 126.
Scheme 25: Synthesis of meso-triazole-bridged porphyrin star trimer 129.
Scheme 26: Synthesis of 1,2,3-triazole-linked porphyrin-β-CD conjugates 131a,b.
Scheme 27: Synthesis of tritriazole-bridged porphyrin-lantern-DNA sequence 134.
Scheme 28: Synthesis of meso-triazole-linked porphyrin-polymer conjugates 137 and 139.
Scheme 29: Synthesis of triazole-linked capped porphyrin 142; Reaction conditions: method A: 10% H2O in THF, C...
Scheme 30: Synthesis of meso-tetratriazole-linked porphyrin-maleimine conjugates 145a–c.
Scheme 31: Synthesis of meso-tetratriazole-linked porphyrin-cholic acid complex 148a,b.
Scheme 32: Synthesis of meso-tetratriazole-linked porphyrin conjugates 151–153.
Scheme 33: Synthesis of meso-tetratrizole-porphyrin-carborane conjugates 155, 156 and 158a–c.
Scheme 34: Synthesis of meso-tetratriazole-porphyrin-cardanol conjugates 160 and 162.
Scheme 35: Synthesis of meso-tetratriazole-linked porphyrin-BODIPY conjugate 164.
Scheme 36: Synthesis of meso-tetratriazole-linked porphyrin-β-CD conjugates 166a,b.
Scheme 37: Synthesis of tetratriazole-bridged meso-arylporphyrins 171a–c and 172a–c.
Scheme 38: Synthesis of octatriazole-bridged porphyrin-β-CD conjugate 174 and porphyrin-adamantane conjugates ...
Discrimination of β-cyclodextrin/hazelnut (Corylus avellana L.) oil/flavonoid glycoside and flavonolignan ternary complexes by Fourier-transform infrared spectroscopy coupled with principal component analysis
- Nicoleta G. Hădărugă,
- Gabriela Popescu,
- Dina Gligor (Pane),
- Cristina L. Mitroi,
- Sorin M. Stanciu and
- Daniel Ioan Hădărugă
Beilstein J. Org. Chem. 2023, 19, 380–398, doi:10.3762/bjoc.19.30
Graphical Abstract
Figure 1: Hypothetical interactions between the β-cyclodextrin host and guest molecules (flavonoid glycoside/...
Figure 2: Superposition of the FTIR spectra for the β-cyclodextrin/Corylus avellana oil/hesperidin ternary co...
Figure 3: Superposition of the FTIR spectra for the β-cyclodextrin/Corylus avellana oil/hesperidin ternary co...
Figure 4: PC2 versus PC1 scores plot from the FTIR–PCA analysis of the flavonoid glycoside and flavonolignan ...
Figure 5: PC2 versus PC1 scores plot from the FTIR–PCA analysis of the β-CD/hazelnut oil/flavonoid ternary co...
Figure 6: PC2 versus PC1 scores plot from the FTIR–PCA analysis of the β-CD/hazelnut oil/flavonoid ternary co...
Figure 7: PC2 versus PC1 scores plot from the FTIR–PCA analysis of the β-CD/hazelnut oil/flavonoid ternary co...
Figure 8: PC3 versus PC1 scores plot from the FTIR-PCA analysis of the β-CD/hazelnut oil/flavonoid ternary co...
Figure 9: PC3 versus PC2 scores plot from the FTIR–PCA analysis of the β-CD/hazelnut oil/flavonoid ternary co...
Figure 10: PC2 versus PC1 loadings plot from the FTIR–PCA analysis of the β-CD/hazelnut oil/flavonoid ternary ...
Figure 11: PC3 versus PC1 loadings plot from the FTIR–PCA analysis of the β-CD/hazelnut oil/flavonoid ternary ...
Figure 12: Eigenvalues of the correlation matrix from the FTIR–PCA analysis of the β-CD/hazelnut oil/flavonoid...
Combretastatins D series and analogues: from isolation, synthetic challenges and biological activities
- Jorge de Lima Neto and
- Paulo Henrique Menezes
Beilstein J. Org. Chem. 2023, 19, 399–427, doi:10.3762/bjoc.19.31
Graphical Abstract
Figure 1: Structures of some members of the combretastatin D series, corniculatolides, and isocorniculatolide...
Scheme 1: Biosynthetic pathway proposed by Pettit and co-workers.
Scheme 2: Biosynthetic pathway towards corniculatolides or isocorniculatolides proposed by Ponnapalli and co-...
Scheme 3: Retrosynthetic approaches.
Scheme 4: Attempt of total synthesis of 2 by Boger and co-workers employing the Mitsunobu approach [27].
Scheme 5: Total synthesis of combretastatin D-2 (2) reported by Boger and co-workers employing an intramolecu...
Scheme 6: Formal synthesis of combretastatin D-2 (2) by Deshpande and co-workers using the Mitsunobu conditio...
Scheme 7: Total synthesis of combretastatin D-2 (2) by Rychnovsky and Hwang [36].
Scheme 8: Divergent synthesis of (±)-1 form combretastatin D-2 (2) by Rychnovsky and Hwang [36].
Scheme 9: Enantioselective synthesis of 1 by Rychnovsky and Hwang employing Jacobsen catalyst [41].
Scheme 10: Synthesis of fragment 57 by Couladouros and co-workers [43,45].
Scheme 11: Formal synthesis of compound 2 by Couladouros and co-workers [43,45].
Scheme 12: Synthesis of fragment 66 by Couladouros and co-workers [44,45].
Scheme 13: Synthesis of fragment 70 by Couladouros and co-workers [44,45].
Scheme 14: Synthesis of fragment 77 by Couladouros and co-workers [44,45].
Scheme 15: Synthesis of combretastatins 1 and 2 by Couladouros and co-workers [44,45].
Scheme 16: Formal synthesis of compound 2 by Gangakhedkar and co-workers [48].
Scheme 17: Synthesis of fragment 14 by Cousin and co-workers [50].
Scheme 18: Synthesis of fragment 91 by Cousin and co-workers [50].
Scheme 19: Formal synthesis of compound 2 by Cousin and co-workers [50].
Scheme 20: Synthesis of 2 diolide by Cousin and co-workers [50].
Scheme 21: Synthesis of combretastatin D-4 (4) by Nishiyama and co-workers [54].
Scheme 22: Synthesis of fragment 112 by Pettit and co-workers [55].
Scheme 23: Synthesis of fragment 114 by Pettit and co-workers [55].
Scheme 24: Attempt to the synthesis of compound 2 by Pettit and co-workers [55].
Scheme 25: Synthesis of combretastatin-D2 (2) starting from isovanilin (80) by Pettit and co-workers [55].
Scheme 26: Attempted synthesis of combretastatin-D2 (2) derivatives through an SNAr approach [55].
Scheme 27: Synthesis of combretastatin D-4 (4) by Pettit and co-workers [55].
Scheme 28: Synthesis of combretastatin D-2 (2) by Harras and co-workers [57].
Scheme 29: Synthesis of combretastatin D-4 (4) by Harras and co-workers [57].
Scheme 30: Formal synthesis of combretastatin D-1 (1) by Harras and co-workers [57].
Scheme 31: Synthesis of 11-O-methylcorniculatolide A (5) by Raut and co-workers [69].
Scheme 32: Synthesis of isocorniculatolide A (7) and O-methylated isocorniculatolide A 8 by Raut and co-worker...
Scheme 33: Synthesis of isocorniculatolide B (10) and hydroxyisocorniculatolide B 175 by Kim and co-workers [71].
Scheme 34: Synthesis of compound 9, 178, and 11 by Kim and co-workers [71].
Scheme 35: Synthesis of combretastatin D-2 prodrug salts [55].
Figure 2: ED50 values of the combretastatin D family against murine P388 lymphocytic leukemia cell line (appr...
Figure 3: IC50 of compounds against α-glucosidase [19].
Asymmetric synthesis of a stereopentade fragment toward latrunculins
- Benjamin Joyeux,
- Antoine Gamet,
- Nicolas Casaretto and
- Bastien Nay
Beilstein J. Org. Chem. 2023, 19, 428–433, doi:10.3762/bjoc.19.32
Graphical Abstract
Figure 1: Structure of latrunculins (the red dots show the natural product stereopentade).
Figure 2: General strategy for latrunculin cycle disconnections (left), previous works towards linear precurs...
Scheme 1: Synthesis of fragment 15 from (+)-β-citronellene (10).
Scheme 2: Synthesis of fragment 8 from ʟ-cysteine ethyl ester hydrochloride (16).
Scheme 3: Synthesis of fragment 21 through a stereoselective aldol reaction.
Scheme 4: 1,3-Anti-diastereoselective reduction of 21 with PNBz transposition, and final determination of the...
Dipeptide analogues of fluorinated aminophosphonic acid sodium salts as moderate competitive inhibitors of cathepsin C
- Karolina Wątroba,
- Małgorzata Pawełczak and
- Marcin Kaźmierczak
Beilstein J. Org. Chem. 2023, 19, 434–439, doi:10.3762/bjoc.19.33
Graphical Abstract
Scheme 1: Synthetic strategy towards 5 and 7.
Scheme 2: Synthesis of 9 and 11. (a) R = -CH3; (b) R = -CH(CH3)2; (c) R = -CH2CH(CH3)2; (d) R = -CH(CH3)CH2CH3...
Figure 1: Dixon plot for the hydrolysis of Gly-Phe-pNA substrate catalyzed by bovine cathepsin C in the prese...
Mechanochemical solid state synthesis of copper(I)/NHC complexes with K3PO4
- Ina Remy-Speckmann,
- Birte M. Zimmermann,
- Mahadeb Gorai,
- Martin Lerch and
- Johannes F. Teichert
Beilstein J. Org. Chem. 2023, 19, 440–447, doi:10.3762/bjoc.19.34
Graphical Abstract
Scheme 1: General synthetic routes to copper(I)/NHC complexes (X = Cl, Br).
Scheme 2: Preparation of sophisticated Cu(I)/NHC complexes: Synthesis of bifunctional catalyst 5 via transmet...
Scheme 3: Application of bifunctional catalyst 5 in copper(I)-catalyzed hydrogenations: comparison of 5 prepa...
Transition-metal-catalyzed C–H bond activation as a sustainable strategy for the synthesis of fluorinated molecules: an overview
- Louis Monsigny,
- Floriane Doche and
- Tatiana Besset
Beilstein J. Org. Chem. 2023, 19, 448–473, doi:10.3762/bjoc.19.35
Graphical Abstract
Scheme 1: Transition-metal-catalyzed C–XRF bond formation by C–H bond activation: an overview.
Scheme 2: Cu(OAc)2-promoted mono- and ditrifluoromethylthiolation of benzamide derivatives derived from 8-ami...
Scheme 3: Trifluoromethylthiolation of azacalix[1]arene[3]pyridines using copper salts and a nucleophilic SCF3...
Scheme 4: Working hypothesis for the palladium-catalyzed C–H trifluoromethylthiolation reaction.
Scheme 5: Trifluoromethylthiolation of 2-arylpyridine derivatives and analogs by means of palladium-catalyzed...
Scheme 6: C(sp2)–SCF3 bond formation by Pd-catalyzed C–H bond activation using AgSCF3 and Selectfluor® as rep...
Scheme 7: Palladium-catalyzed ortho-trifluoromethylthiolation of 2-arylpyridine derivatives reported by the g...
Scheme 8: Palladium-catalyzed ortho-trifluoromethylthiolation of 2-arylpyridine and analogs reported by Anbar...
Scheme 9: Mono- and ditrifluoromethylthiolation of benzamide derivatives derived from 8-aminoquinoline using ...
Scheme 10: Regioselective Cp*Rh(III)-catalyzed directed trifluoromethylthiolation reported by the group of Li [123]...
Scheme 11: Cp*Co(III)-catalyzed ortho-trifluoromethylthiolation of 2-phenylpyridine and 2-phenylpyrimidine der...
Scheme 12: Cp*Co(III)-catalyzed ortho-trifluoromethylthiolation of 2-phenylpyridine and 6-phenylpurine derivat...
Scheme 13: Diastereoselective trifluoromethylthiolation of acrylamide derivatives derived from 8-aminoquinolin...
Scheme 14: C(sp3)–SCF3 bond formation on aliphatic amide derivatives derived from 8-aminoquinoline by palladiu...
Scheme 15: Regio- and diastereoselective difluoromethylthiolation of acrylamides under palladium catalysis rep...
Scheme 16: Palladium-catalyzed (ethoxycarbonyl)difluoromethylthiolation reaction of 2-(hetero)aryl and 2-(α-ar...
Scheme 17: Pd(II)-catalyzed trifluoromethylselenolation of benzamides derived from 5-methoxy-8-aminoquinoline ...
Scheme 18: Pd(II)-catalyzed trifluoromethylselenolation of acrylamide derivatives derived from 5-methoxy-8-ami...
Scheme 19: Transition-metal-catalyzed dehydrogenative 2,2,2-trifluoroethoxylation of (hetero)aromatic derivati...
Scheme 20: Pd(II)-catalyzed ortho-2,2,2-trifluoroethoxylation of N-sulfonylbenzamides reported by the group of...
Scheme 21: Pd(II)-catalyzed selective 2,2,2-trifluoroethoxylation and other fluoroalkoxylations of naphthalene...
Scheme 22: Pd(II)-catalyzed selective ortho-2,2,2-trifluoroethoxylation of benzaldehyde derivatives by means o...
Scheme 23: Pd(II)-catalyzed selective ortho-2,2,2-trifluoroethoxylation (and other fluoroalkoxylations) of ben...
Scheme 24: Pd(II)-catalyzed selective 2,2,2-trifluoroethoxylation of aliphatic amides using a bidentate direct...
Total synthesis: an enabling science
- Bastien Nay
Beilstein J. Org. Chem. 2023, 19, 474–476, doi:10.3762/bjoc.19.36
Graphical Abstract
Figure 1: A summary of compounds targeted in this thematic issue.
Computational studies of Brønsted acid-catalyzed transannular cycloadditions of cycloalkenone hydrazones
- Manuel Pedrón,
- Jana Sendra,
- Irene Ginés,
- Tomás Tejero,
- Jose L. Vicario and
- Pedro Merino
Beilstein J. Org. Chem. 2023, 19, 477–486, doi:10.3762/bjoc.19.37
Graphical Abstract
Scheme 1: Experimental data (series a–d, k) and non-studied examples (series e–j) for transannular cycloaddit...
Figure 1: Optimized (m062x/6-31G(d)) geometries for the transition structures of series a–f.
Figure 2: Top: Cycloaddition of protonated hydrazones as inverse-demand reaction of cycloaddition of azomethi...
Figure 3: Global electron density transfer (GEDT). Dashed black line indicates both TS.
Figure 4: ELF analysis for the reaction of series b leading to a system 6-6. Black trace corresponds to IRC. ...
Figure 5: Quantitative NCI analysis [36] for the reaction of series a–f leading to fused cyclohexanes. The result...
Figure 6: (a) Transannular cycloadditons of compounds 1a–k. (b) Houk’s distortion model applied to the reacti...
Scheme 2: Reaction with simple models.
Transition-metal-catalyzed domino reactions of strained bicyclic alkenes
- Austin Pounder,
- Eric Neufeld,
- Peter Myler and
- William Tam
Beilstein J. Org. Chem. 2023, 19, 487–540, doi:10.3762/bjoc.19.38
Graphical Abstract
Figure 1: Ring-strain energies of homobicyclic and heterobicyclic alkenes in kcal mol−1. a) [2.2.1]-Bicyclic ...
Figure 2: a) Exo and endo face descriptions of bicyclic alkenes. b) Reactivity comparisons for different β-at...
Scheme 1: Ni-catalyzed ring-opening/cyclization cascade of heterobicyclic alkenes 1 with alkyl propiolates 2 ...
Scheme 2: Ni-catalyzed ring-opening/cyclization cascade of heterobicyclic alkenes 8 with β-iodo-(Z)-propenoat...
Scheme 3: Ni-catalyzed two- and three-component difunctionalizations of norbornene derivatives 15 with alkyne...
Scheme 4: Ni-catalyzed intermolecular three-component difunctionalization of oxabicyclic alkenes 1 with alkyn...
Scheme 5: Ni-catalyzed intermolecular three-component carboacylation of norbornene derivatives 15.
Scheme 6: Photoredox/Ni dual-catalyzed coupling of 4-alkyl-1,4-dihydropyridines 31 with heterobicyclic alkene...
Scheme 7: Photoredox/Ni dual-catalyzed coupling of α-amino radicals with heterobicyclic alkenes 30.
Scheme 8: Cu-catalyzed rearrangement/allylic alkylation of 2,3-diazabicyclo[2.2.1]heptenes 47 with Grignard r...
Scheme 9: Cu-catalyzed aminoboration of bicyclic alkenes 1 with bis(pinacolato)diboron (B2pin2) (53) and O-be...
Scheme 10: Cu-catalyzed borylalkynylation of oxabenzonorbornadiene (30b) with B2pin2 (53) and bromoalkynes 62.
Scheme 11: Cu-catalyzed borylacylation of bicyclic alkenes 1.
Scheme 12: Cu-catalyzed diastereoselective 1,2-difunctionalization of oxabenzonorbornadienes 30 for the synthe...
Scheme 13: Fe-catalyzed carbozincation of heterobicyclic alkenes 1 with arylzinc reagents 74.
Scheme 14: Co-catalyzed addition of arylzinc reagents of norbornene derivatives 15.
Scheme 15: Co-catalyzed ring-opening/dehydration of oxabicyclic alkenes 30 via C–H activation of arenes.
Scheme 16: Co-catalyzed [3 + 2] annulation/ring-opening/dehydration domino reaction of oxabicyclic alkenes 1 w...
Scheme 17: Co-catalyzed enantioselective carboamination of bicyclic alkenes 1 via C–H functionalization.
Scheme 18: Ru-catalyzed cyclization of oxabenzonorbornene derivatives with propargylic alcohols for the synthe...
Scheme 19: Ru-catalyzed coupling of oxabenzonorbornene derivatives 30 with propargylic alcohols and ethers 106...
Scheme 20: Ru-catalyzed ring-opening/dehydration of oxabicyclic alkenes via the C–H activation of anilides.
Scheme 21: Ru-catalyzed of azabenzonorbornadiene derivatives with arylamides.
Scheme 22: Rh-catalyzed cyclization of bicyclic alkenes with arylboronate esters 118.
Scheme 23: Rh-catalyzed cyclization of bicyclic alkenes with dienyl- and heteroaromatic boronate esters.
Scheme 24: Rh-catalyzed domino lactonization of doubly bridgehead-substituted oxabicyclic alkenes with seconda...
Scheme 25: Rh-catalyzed domino carboannulation of diazabicyclic alkenes with 2-cyanophenylboronic acid and 2-f...
Scheme 26: Rh-catalyzed synthesis of oxazolidinone scaffolds 147 through a domino ARO/cyclization of oxabicycl...
Scheme 27: Rh-catalyzed oxidative coupling of salicylaldehyde derivatives 151 with diazabicyclic alkenes 130a.
Scheme 28: Rh-catalyzed reaction of O-acetyl ketoximes with bicyclic alkenes for the synthesis of isoquinoline...
Scheme 29: Rh-catalyzed domino coupling reaction of 2-phenylpyridines 165 with oxa- and azabicyclic alkenes 30....
Scheme 30: Rh-catalyzed domino dehydrative naphthylation of oxabenzonorbornadienes 30 with N-sulfonyl 2-aminob...
Scheme 31: Rh-catalyzed domino dehydrative naphthylation of oxabenzonorbornadienes 30 with arylphosphine deriv...
Scheme 32: Rh-catalyzed domino ring-opening coupling reaction of azaspirotricyclic alkenes using arylboronic a...
Scheme 33: Tandem Rh(III)/Sc(III)-catalyzed domino reaction of oxabenzonorbornadienes 30 with alkynols 184 dir...
Scheme 34: Rh-catalyzed asymmetric domino cyclization and addition reaction of 1,6-enynes 194 and oxa/azabenzo...
Scheme 35: Rh/Zn-catalyzed domino ARO/cyclization of oxabenzonorbornadienes 30 with phosphorus ylides 201.
Scheme 36: Rh-catalyzed domino ring opening/lactonization of oxabenzonorbornadienes 30 with 2-nitrobenzenesulf...
Scheme 37: Rh-catalyzed domino C–C/C–N bond formation of azabenzonorbornadienes 30 with aryl-2H-indazoles 210.
Scheme 38: Rh/Pd-catalyzed domino synthesis of indole derivatives with 2-(phenylethynyl)anilines 212 and oxabe...
Scheme 39: Rh-catalyzed domino carborhodation of heterobicyclic alkenes 30 with B2pin2 (53).
Scheme 40: Rh-catalyzed three-component 1,2-carboamidation reaction of bicyclic alkenes 30 with aromatic and h...
Scheme 41: Pd-catalyzed diarylation and dialkenylation reactions of norbornene derivatives.
Scheme 42: Three-component Pd-catalyzed arylalkynylation reactions of bicyclic alkenes.
Scheme 43: Three-component Pd-catalyzed arylalkynylation reactions of norbornene and DFT mechanistic study.
Scheme 44: Pd-catalyzed three-component coupling N-tosylhydrazones 236, aryl halides 66, and norbornene (15a).
Scheme 45: Pd-catalyzed arylboration and allylboration of bicyclic alkenes.
Scheme 46: Pd-catalyzed, three-component annulation of aryl iodides 66, alkenyl bromides 241, and bicyclic alk...
Scheme 47: Pd-catalyzed double insertion/annulation reaction for synthesizing tetrasubstituted olefins.
Scheme 48: Pd-catalyzed aminocyclopropanation of bicyclic alkenes 1 with 5-iodopent-4-enylamine derivatives 249...
Scheme 49: Pd-catalyzed, three-component coupling of alkynyl bromides 62 and norbornene derivatives 15 with el...
Scheme 50: Pd-catalyzed intramolecular cyclization/ring-opening reaction of heterobicyclic alkenes 30 with 2-i...
Scheme 51: Pd-catalyzed dimer- and trimerization of oxabenzonorbornadiene derivatives 30 with anhydrides 268.
Scheme 52: Pd-catalyzed Catellani-type annulation and retro-Diels–Alder of norbornadiene 15b yielding fused xa...
Scheme 53: Pd-catalyzed hydroarylation and heteroannulation of urea-derived bicyclic alkenes 158 and aryl iodi...
Scheme 54: Access to fused 8-membered sulfoximine heterocycles 284/285 via Pd-catalyzed Catellani annulation c...
Scheme 55: Pd-catalyzed 2,2-bifunctionalization of bicyclic alkenes 1 generating spirobicyclic xanthone deriva...
Scheme 56: Pd-catalyzed Catellani-type annulation and retro-Diels–Alder of norbornadiene (15b) producing subst...
Scheme 57: Pd-catalyzed [2 + 2 + 1] annulation furnishing bicyclic-fused indanes 281 and 283.
Scheme 58: Pd-catalyzed ring-opening/ring-closing cascade of diazabicyclic alkenes 130a.
Scheme 59: Pd-NHC-catalyzed cyclopentannulation of diazabicyclic alkenes 130a.
Scheme 60: Pd-catalyzed annulation cascade generating diazabicyclic-fused indanones 292 and indanols 294.
Scheme 61: Pd-catalyzed skeletal rearrangement of spirotricyclic alkenes 176 towards large polycyclic benzofur...
Scheme 62: Pd-catalyzed oxidative annulation of aromatic enamides 298 and diazabicyclic alkenes 130a.
Scheme 63: Accessing 3,4,5-trisubstituted cyclopentenes 300, 301, 302 via the Pd-catalyzed domino reaction of ...
Scheme 64: Palladacycle-catalyzed ring-expansion/cyclization domino reactions of terminal alkynes and bicyclic...
Scheme 65: Pd-catalyzed carboesterification of norbornene (15a) with alkynes, furnishing α-methylene γ-lactone...
Access to cyclopropanes with geminal trifluoromethyl and difluoromethylphosphonate groups
- Ita Hajdin,
- Romana Pajkert,
- Mira Keßler,
- Jianlin Han,
- Haibo Mei and
- Gerd-Volker Röschenthaler
Beilstein J. Org. Chem. 2023, 19, 541–549, doi:10.3762/bjoc.19.39
Graphical Abstract
Scheme 1: Previous works (A–D) and the extension (this work).
Scheme 2: Synthesis of diethyl 2-diazo-1,1,3,3,3-pentafluoropropylphosphonate (5).
Scheme 3: Scope of the cyclopropanation. Reaction conditions: alkene (0.15 mmol), diazo compound 5 (0.1 mmol)...
Figure 1: 19F,1H-HOESY spectrum of compound 6c.
Scheme 4: Scope of the cyclopropanation. Reaction conditions: alkene (0.15 mmol), diazo compound 5 (0.1 mmol)...
Scheme 5: Addition of CuI to the diazo compound 5.
Scheme 6: Possible addition of styrene to Int2 yielding Int4_1 and Int4_2 through Int3_1 and Int3_2.
Scheme 7: Possible addition of styrene to Int2 yielding Int4_3 and Int4_4 without further intermediates.
Scheme 8: Formation of the products Pr1 to Pr4.
Phenanthridine–pyrene conjugates as fluorescent probes for DNA/RNA and an inactive mutant of dipeptidyl peptidase enzyme
- Josipa Matić,
- Tana Tandarić,
- Marijana Radić Stojković,
- Filip Šupljika,
- Zrinka Karačić,
- Ana Tomašić Paić,
- Lucija Horvat,
- Robert Vianello and
- Lidija-Marija Tumir
Beilstein J. Org. Chem. 2023, 19, 550–565, doi:10.3762/bjoc.19.40
Graphical Abstract
Scheme 1: Novel pyrene–phenanthridine conjugates Phen-Py-1 (longer, flexible linker) and Phen-Py-2 (shorter, ...
Scheme 2: Synthesis of Phen-Py-1 and Phen-Py-2 by amide formation; Reagents and conditions: 1. TFA–H2O mixtur...
Figure 1: 2D (left) and 3D (right) representation of fluorescence emission spectra of Phen-Py-1 (c = 2 × 10−6...
Figure 2: Most representative structures of the conjugates Phen-Py-1 and Phen-Py-2 at different pH conditions...
Figure 3: UV–vis titration of Phen-Py-1 with ct-DNA,; changes in the UV–vis spectra of Phen-Py-1 at λ = 350 n...
Figure 4: . Experimental (■) and calculated (–) (by Scatchard equation Table 2) fluorescence intensities of compound ...
Figure 5: Comparison of spectra of DNA-dye complex (r = 0.5, black) and sum of DNA and dye spectra (red) of a...
Figure 6: Fluorimetric titration of Phen-Py-1, λexc = 352 nm, c = 1 × 10−6 mol dm−3 with dipeptidyl peptidase...
Figure 7: A: ITC titration: raw titration data from the experimental injections of human DPP III enzyme mutan...
A new oxidatively stable ligand for the chiral functionalization of amino acids in Ni(II)–Schiff base complexes
- Alena V. Dmitrieva,
- Oleg A. Levitskiy,
- Yuri K. Grishin and
- Tatiana V. Magdesieva
Beilstein J. Org. Chem. 2023, 19, 566–574, doi:10.3762/bjoc.19.41
Graphical Abstract
Scheme 1: Selected examples of the chiral ligands used for synthesis of the Ni(II)–Schiff base complexes.
Scheme 2: Synthesis of the chiral ligand L7 and its Ni(II) complexes with glycine, serine, dehydroalanine, an...
Figure 1: Fragment of the NOESY spectrum of the ʟ-(oBrCysNi)L7 complex indicating the correlation between the...
Figure 2: Low-gradient isosurfaces with low densities (blue color of the isosurface corresponds to the hydrog...
Figure 3: Saturated solutions of (GlyNi)L1 (left) and (GlyNi)L7 (right) in diethyl ether.
Figure 4: The CV curves observed for (GlyNi)L7 and (ΔAlaNi)L7 in the anodic and cathodic regions (Pt, CH3CN, ...
Direct C2–H alkylation of indoles driven by the photochemical activity of halogen-bonded complexes
- Martina Mamone,
- Giuseppe Gentile,
- Jacopo Dosso,
- Maurizio Prato and
- Giacomo Filippini
Beilstein J. Org. Chem. 2023, 19, 575–581, doi:10.3762/bjoc.19.42
Graphical Abstract
Figure 1: (a) Exploitation of an EDA complex in organic synthesis. (b) This work: use of halogen-bonded compl...
Figure 2: Optical absorption spectra recorded in acetonitrile in 1 cm path quartz cuvettes. [DABCO]: 0.5 M; [...
Figure 3: 1H NMR titration of DABCO in a solution of 2a in ACN-d3 to detect their halogen-bonding association...
Figure 4: Proposed reaction mechanism for the photochemical alkylation of 1a with the α-iodosulfone 2a in the...
Scheme 1: Study of scope of the HAS reaction between indoles 1 and α-iodosulfones 2. Yields in parentheses we...
C3-Alkylation of furfural derivatives by continuous flow homogeneous catalysis
- Grédy Kiala Kinkutu,
- Catherine Louis,
- Myriam Roy,
- Juliette Blanchard and
- Julie Oble
Beilstein J. Org. Chem. 2023, 19, 582–592, doi:10.3762/bjoc.19.43
Graphical Abstract
Scheme 1: C3-Functionalization of furfural derivatives by C–H activation, a) in batch: previous works, and b)...
Scheme 2: C3-alkylation of bidentate imine 1 performed in batch.
Scheme 3: Optimization of the heating for the alkylation reaction on the homemade pulsed-flow setup.
Scheme 4: Proposed reaction mechanism for the alkylation reaction with formation of ruthenium aggregates and ...
Scheme 5: A) Isolation test of a reaction intermediate; B) XPS and TEM (in ethanol) of the recovered solid ph...
Scheme 6: Ruthenium aggregate-catalyzed alkylation reaction.
Scheme 7: Scope of continuous flow furfural derivative alkylation reaction.
Scheme 8: Scaling up comparison: batch and continuous flow conditions.
Enolates ambushed – asymmetric tandem conjugate addition and subsequent enolate trapping with conventional and less traditional electrophiles
- Péter Kisszékelyi and
- Radovan Šebesta
Beilstein J. Org. Chem. 2023, 19, 593–634, doi:10.3762/bjoc.19.44
Graphical Abstract
Scheme 1: General scheme depicting tandem reactions based on an asymmetric conjugate addition followed by an ...
Scheme 2: Cu-catalyzed tandem conjugate addition of R2Zn/aldol reaction with chiral acetals.
Scheme 3: Cu-catalyzed asymmetric desymmetrization of cyclopentene-1,3-diones using a tandem conjugate additi...
Scheme 4: Stereocontrolled assembly of dialkylzincs, cyclic enones, and sulfinylimines utilizing a Cu-catalyz...
Scheme 5: Cu-catalyzed tandem conjugate addition/Mannich reaction (A). Access to chiral isoindolinones and tr...
Scheme 6: Cu-catalyzed tandem conjugate addition/nitro-Mannich reaction (A) with syn–anti or syn–syn selectiv...
Figure 1: Various chiral ligands utilized for the tandem conjugate addition/Michael reaction sequences.
Scheme 7: Cu-catalyzed tandem conjugate addition/Michael reaction: side-product formation with chalcone (A) a...
Scheme 8: Zn enolate trapping using allyl iodides (A), Stork–Jung vinylsilane reagents (B), and allyl bromide...
Scheme 9: Cu-catalyzed tandem conjugate addition/acylation through Li R2Zn enolate (A). A four-component coup...
Scheme 10: Selected examples for the Cu-catalyzed tandem conjugate addition/trifluoromethylthiolation sequence....
Scheme 11: Zn enolates trapped by vinyloxiranes: synthesis of allylic alcohols.
Scheme 12: Stereoselective cyclopropanation of Mg enolates formed by ACA of Grignard reagents to chlorocrotona...
Scheme 13: Domino aldol reactions of Mg enolates formed from coumarin and chromone.
Scheme 14: Oxidative coupling of ACA-produced Mg enolates.
Scheme 15: Tandem ACA of Grignard reagents to enones and Mannich reaction.
Scheme 16: Diastereodivergent Mannich reaction of Mg enolates with differently N-protected imines.
Scheme 17: Tandem Grignard–ACA–Mannich using Taddol-based phosphine-phosphite ligands.
Scheme 18: Tandem reaction of Mg enolates with aminomethylating reagents.
Scheme 19: Tandem reaction composed of Grignard ACA to alkynyl enones.
Scheme 20: Rh/Cu-catalyzed tandem reaction of diazo enoates leading to cyclobutanes.
Scheme 21: Tandem Grignard-ACA of cyclopentenones and alkylation of enolates.
Scheme 22: Tandem ACA of Grignard reagents followed by enolate trapping reaction with onium compounds.
Scheme 23: Mg enolates generated from unsaturated lactones in reaction with activated alkenes.
Scheme 24: Lewis acid mediated ACA to amides and SN2 cyclization of a Br-appended enolate.
Scheme 25: Trapping reactions of aza-enolates with Michael acceptors.
Scheme 26: Si enolates generated by TMSOTf-mediated ACA of Grignard reagents and enolate trapping reaction wit...
Scheme 27: Trapping reactions of enolates generated from alkenyl heterocycles (A) and carboxylic acids (B) wit...
Scheme 28: Reactions of heterocyclic Mg enolates with onium compounds.
Scheme 29: Synthetic transformations of cycloheptatrienyl and benzodithiolyl substituents.
Scheme 30: Aminomethylation of Al enolates generated by ACA of trialkylaluminum reagents.
Scheme 31: Trapping reactions of enolates with activated alkenes.
Scheme 32: Alkynylation of racemic aluminum or magnesium enolates.
Scheme 33: Trapping reactions of Zr enolates generated by Cu-ACA of organozirconium reagents.
Scheme 34: Chloromethylation of Zr enolates using the Vilsmeier–Haack reagent.
Scheme 35: Tandem conjugate borylation with subsequent protonation or enolate trapping by an electrophile.
Scheme 36: Tandem conjugate borylation/aldol reaction of cyclohexenones.
Scheme 37: Selected examples for the tandem asymmetric borylation/intramolecular aldol reaction; synthesis of ...
Scheme 38: Cu-catalyzed tandem methylborylation of α,β-unsaturated phosphine oxide in the presence of (R,Sp)-J...
Scheme 39: Cu-catalyzed tandem transannular conjugated borylation/aldol cyclization of macrocycles containing ...
Scheme 40: Stereoselective tandem conjugate borylation/Mannich cyclization: selected examples (A) and a multi-...
Scheme 41: Some examples of Cu-catalyzed asymmetric tandem borylation/aldol cyclization (A). Application to di...
Scheme 42: Atropisomeric P,N-ligands used in tandem conjugate borylation/aldol cyclization sequence.
Scheme 43: Selected examples for the enantioselective Cu-catalyzed borylation/intramolecular Michael addition ...
Scheme 44: Selected examples for the preparation of enantioenriched spiroindanes using a Cu-catalyzed tandem c...
Scheme 45: Enantioselective conjugate borylation of cyclobutene-1-carboxylic acid diphenylmethyl ester 175 wit...
Scheme 46: Cu-catalyzed enantioselective tandem conjugate silylation of α,β-unsaturated ketones with subsequen...
Scheme 47: Cu-catalyzed enantioselective tandem conjugate silylation of α,β-unsaturated ketones with subsequen...
Scheme 48: Cu-catalyzed tandem conjugate silylation/aldol condensation. The diastereoselectivity is controlled...
Scheme 49: Chiral Ru-catalyzed three-component coupling reaction.
Scheme 50: Rh-Phebox complex-catalyzed reductive cyclization and subsequent reaction with Michael acceptors th...
Scheme 51: Rh-catalyzed tandem asymmetric conjugate alkynylation/aldol reaction (A) and subsequent spiro-cycli...
Scheme 52: Rh-bod complex-catalyzed tandem asymmetric conjugate arylation/intramolecular aldol addition (A). S...
Scheme 53: Co-catalyzed C–H-bond activation/asymmetric conjugate addition/aldol reaction.
Scheme 54: (Diisopinocampheyl)borane-promoted 1,4-hydroboration of α,β-unsaturated morpholine carboxamides and...
Figure 2: Some examples of total syntheses that have been recently reviewed.
Scheme 55: Stereoselective synthesis of antimalarial prodrug (+)-artemisinin utilizing a tandem conjugate addi...
Scheme 56: Amphilectane and serrulatane diterpenoids: preparation of chiral starting material via asymmetric t...
Scheme 57: Various asymmetric syntheses of pleuromutilin and related compounds based on a tandem conjugate add...
Scheme 58: Total synthesis of glaucocalyxin A utilizing a tandem conjugate addition/acylation reaction sequenc...
Scheme 59: Installation of the exocyclic double bond using a tandem conjugate addition/aminomethylation sequen...
Scheme 60: Synthesis of the taxol core using a tandem conjugate addition/enolate trapping sequence with Vilsme...
Scheme 61: Synthesis of the tricyclic core of 12-epi-JBIR-23/24 utilizing a Rh-catalyzed asymmetric conjugate ...
Scheme 62: Total synthesis of (−)-peyssonoside A utilizing a Cu-catalyzed enantioselective tandem conjugate ad...
