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Search for "air stability" in Full Text gives 14 result(s) in Beilstein Journal of Organic Chemistry.
Organic electron transport materials
- Joseph Cameron and
- Peter J. Skabara
Beilstein J. Org. Chem. 2024, 20, 672–674, doi:10.3762/bjoc.20.60
- orthogonal processing. One of the biggest challenges with n-type materials is air stability. This is explained by the redox potentials of water (−0.66 V vs standard calomel electrode (SCE)) and oxygen (+0.024 V vs SCE, +0.57 V vs SCE) [2][3]. Therefore, it has been observed that once the overpotential
Benzoimidazolium-derived dimeric and hydride n-dopants for organic electron-transport materials: impact of substitution on structures, electrochemistry, and reactivity
- Swagat K. Mohapatra,
- Khaled Al Kurdi,
- Samik Jhulki,
- Georgii Bogdanov,
- John Bacsa,
- Maxwell Conte,
- Tatiana V. Timofeeva,
- Seth R. Marder and
- Stephen Barlow
Beilstein J. Org. Chem. 2023, 19, 1651–1663, doi:10.3762/bjoc.19.121
- only introduced in n-dopants in 2010, when Bao and co-workers reported the use of N-DMBI-H (1bH, Figure 1) to n-dope fullerenes [7]. Although widely used, due to their facile synthesis, structural tunability, and good air stability in the solid state, 1H derivatives are relatively limited in dopant
- in 1984 [12]. More recently, dimers 1b2–1f2 (Figure 1) have been used as n-dopants [13][14][15][16][17][18][19][20]. They behave similarly to the closed-shell dimers formed by certain 19-electron transition-metal sandwich compounds [21][22][23], exhibiting moderate air stability and acting as quite
- •+/1H and 12•+/12 potentials are relevant to the air stability of the hydrides and dimers, respectively, as well as to other processes in which 1H or 12 acts as an electron donor, such as the initation step proposed for the radical-chain dehalogenation of α-dihaloketones by a 1H derivative [58] and
Graphical Abstract
Figure 1: DMBI+, DMBI-H, and (DMBI)2 derivatives discussed in this work (new compounds in red).
Scheme 1: Synthesis of DMBI-H and (DMBI)2 derivatives and structures of side products.
Figure 2: Crystallographically characterized molecules related to DMBI dimers.
Figure 3: Molecular structures from the single crystal structures of 1b2 (two crystallographically inequivale...
Figure 4: Molecular structures from the single crystal structures of 1bH (upper left), 1gH (upper right), 1hH...
Figure 5: Structures of the cations from the single crystal structures of 1g+I− (left), 1h+PF6− (center), and ...
Figure 6: Cyclic voltammograms (50 mV s−1, THF, 0.1 M Bu4NPF6) of 1g+PF6–, 1gH, and 1g2, in each case contain...
Figure 7: Acceptors used to examine reactivity of DMBI-H and (DMBI)2 derivatives.
Figure 8: a) Temporal evolution of the absorbance at 1030 nm, corresponding to an absorption maximum of VI•–,...
Electron-rich triarylphosphines as nucleophilic catalysts for oxa-Michael reactions
- Susanne M. Fischer,
- Simon Renner,
- A. Daniel Boese and
- Christian Slugovc
Beilstein J. Org. Chem. 2021, 17, 1689–1697, doi:10.3762/bjoc.17.117
- radical cations of the phosphines under investigation were calculated by density functional theory (DFT), namely B3LYP-def2-TZVPPD. According to criterion introduced by Stewart et al. postulating air stability of phosphines when the SOMO energy is higher than −10 eV, the three derivatives should be air
Graphical Abstract
Scheme 1: Mechanism for the phosphine-initiated oxa-Michael addition.
Figure 1: Above: Michael acceptors, Michael donors and catalysts used in this study; pKa (respectively pKa of...
Figure 2: Left: double-bond conversion of the polymerization of 4 initiated by 5 mol % TPP, MMTPP or TMTPP af...
Figure 3: Left: Oxidation stability of the phosphines. Phosphine oxide content in % as determined by 31P NMR ...
Recent advances on the transition-metal-catalyzed synthesis of imidazopyridines: an updated coverage
- Gagandeep Kour Reen,
- Ashok Kumar and
- Pratibha Sharma
Beilstein J. Org. Chem. 2019, 15, 1612–1704, doi:10.3762/bjoc.15.165
- medium was its environmentally benign nature, air stability and significantly its compatibility with various organic compounds. This reaction was first of its kind in using pyridine-2(1H)-ones (precursor of 2-AP) directly for the synthesis of IPs. The generality of the present protocol lied in tolerance
Graphical Abstract
Figure 1: Various drugs having IP nucleus.
Figure 2: Participation percentage of various TMs for the syntheses of IPs.
Scheme 1: CuI–NaHSO4·SiO2-catalyzed synthesis of imidazo[1,2-a]pyridines.
Scheme 2: Experimental examination of reaction conditions.
Scheme 3: One-pot tandem reaction for the synthesis of 2-haloimidazopyridines.
Scheme 4: Mechanistic scheme for the synthesis of 2-haloimidazopyridine.
Scheme 5: Copper-MOF-catalyzed three-component reaction (3-CR) for imidazo[1,2-a]pyridines.
Scheme 6: Mechanism for copper-MOF-driven synthesis.
Scheme 7: Heterogeneous synthesis via titania-supported CuCl2.
Scheme 8: Mechanism involving oxidative C–H functionalization.
Scheme 9: Heterogeneous synthesis of IPs.
Scheme 10: One-pot regiospecific synthesis of imidazo[1,2-a]pyridines.
Scheme 11: Vinyl azide as an unprecedented substrate for imidazo[1,2-a]pyridines.
Scheme 12: Radical pathway.
Scheme 13: Cu(I)-catalyzed transannulation approach for imidazo[1,5-a]pyridines.
Scheme 14: Plausible radical pathway for the synthesis of imidazo[1,5-a]pyridines.
Scheme 15: A solvent-free domino reaction for imidazo[1,2-a]pyridines.
Scheme 16: Cu-NPs-mediated synthesis of imidazo[1,2-a]pyridines.
Scheme 17: CuI-catalyzed synthesis of isoxazolylimidazo[1,2-a]pyridines.
Scheme 18: Functionalization of 4-bromo derivative via Sonogashira coupling reaction.
Scheme 19: A plausible reaction pathway.
Scheme 20: Cu(I)-catalyzed intramolecular oxidative C–H amidation reaction.
Scheme 21: One-pot synthetic reaction for imidazo[1,2-a]pyridine.
Scheme 22: Plausible reaction mechanism.
Scheme 23: Cu(OAc)2-promoted synthesis of imidazo[1,2-a]pyridines.
Scheme 24: Mechanism for aminomethylation/cycloisomerization of propiolates with imines.
Scheme 25: Three-component synthesis of imidazo[1,2-a]pyridines.
Figure 3: Scope of pyridin-2(1H)-ones and acetophenones.
Scheme 26: CuO NPS-promoted A3 coupling reaction.
Scheme 27: Cu(II)-catalyzed C–N bond formation reaction.
Scheme 28: Mechanism involving Chan–Lam/Ullmann coupling.
Scheme 29: Synthesis of formyl-substituted imidazo[1,2-a]pyridines.
Scheme 30: A tandem sp3 C–H amination reaction.
Scheme 31: Probable mechanistic approach.
Scheme 32: Dual catalytic system for imidazo[1,2-a]pyridines.
Scheme 33: Tentative mechanism.
Scheme 34: CuO/CuAl2O4/ᴅ-glucose-promoted 3-CCR.
Scheme 35: A tandem CuOx/OMS-2-based synthetic strategy.
Figure 4: Biomimetic catalytic oxidation in the presence of electron-transfer mediators (ETMs).
Scheme 36: Control experiment.
Scheme 37: Copper-catalyzed C(sp3)–H aminatin reaction.
Scheme 38: Reaction of secondary amines.
Scheme 39: Probable mechanistic pathway.
Scheme 40: Coupling reaction of α-azidoketones.
Scheme 41: Probable pathway.
Scheme 42: Probable mechanism with free energy calculations.
Scheme 43: MCR for cyanated IP synthesis.
Scheme 44: Substrate scope for the reaction.
Scheme 45: Reaction mechanism.
Scheme 46: Probable mechanistic pathway for Cu/ZnAl2O4-catalyzed reaction.
Scheme 47: Copper-catalyzed double oxidative C–H amination reaction.
Scheme 48: Application towards different coupling reactions.
Scheme 49: Reaction mechanism.
Scheme 50: Condensation–cyclization approach for the synthesis of 1,3-diarylated imidazo[1,5-a]pyridines.
Scheme 51: Optimized reaction conditions.
Scheme 52: One-pot 2-CR.
Scheme 53: One-pot 3-CR without the isolation of chalcone.
Scheme 54: Copper–Pybox-catalyzed cyclization reaction.
Scheme 55: Mechanistic pathway catalyzed by Cu–Pybox complex.
Scheme 56: Cu(II)-promoted C(sp3)-H amination reaction.
Scheme 57: Wider substrate applicability for the reaction.
Scheme 58: Plausible reaction mechanism.
Scheme 59: CuI assisted C–N cross-coupling reaction.
Scheme 60: Probable reaction mechanism involving sp3 C–H amination.
Scheme 61: One-pot MCR-catalyzed by CoFe2O4/CNT-Cu.
Scheme 62: Mechanistic pathway.
Scheme 63: Synthetic scheme for 3-nitroimidazo[1,2-a]pyridines.
Scheme 64: Plausible mechanism for CuBr-catalyzed reaction.
Scheme 65: Regioselective synthesis of halo-substituted imidazo[1,2-a]pyridines.
Scheme 66: Synthesis of 2-phenylimidazo[1,2-a]pyridines.
Scheme 67: Synthesis of diarylated compounds.
Scheme 68: CuBr2-mediated one-pot two-component oxidative coupling reaction.
Scheme 69: Decarboxylative cyclization route to synthesize 1,3-diarylimidazo[1,5-a]pyridines.
Scheme 70: Mechanistic pathway.
Scheme 71: C–H functionalization reaction of enamines to produce diversified heterocycles.
Scheme 72: A plausible mechanism.
Scheme 73: CuI-promoted aerobic oxidative cyclization reaction of ketoxime acetates and pyridines.
Scheme 74: CuI-catalyzed pathway for the formation of imidazo[1,2-a]pyridine.
Scheme 75: Mechanistic pathway.
Scheme 76: Mechanistic rationale for the synthesis of products.
Scheme 77: Copper-catalyzed synthesis of vinyloxy-IP.
Scheme 78: Regioselective product formation with propiolates.
Scheme 79: Proposed mechanism for vinyloxy-IP formation.
Scheme 80: Regioselective synthesis of 3-hetero-substituted imidazo[1,2-a]pyridines with different reaction su...
Scheme 81: Mechanistic pathway.
Scheme 82: CuI-mediated synthesis of 3-formylimidazo[1,2-a]pyridines.
Scheme 83: Radical pathway for 3-formylated IP synthesis.
Scheme 84: Pd-catalyzed urea-cyclization reaction for IPs.
Scheme 85: Pd-catalyzed one-pot-tandem amination and intramolecular amidation reaction.
Figure 5: Scope of aniline nucleophiles.
Scheme 86: Pd–Cu-catalyzed Sonogashira coupling reaction.
Scheme 87: One-pot amide coupling reaction for the synthesis of imidazo[4,5-b]pyridines.
Scheme 88: Urea cyclization reaction for the synthesis of two series of pyridines.
Scheme 89: Amidation reaction for the synthesis of imidazo[4,5-b]pyridines.
Figure 6: Amide scope.
Scheme 90: Pd NPs-catalyzed 3-component reaction for the synthesis of 2,3-diarylated IPs.
Scheme 91: Plausible mechanistic pathway for Pd NPs-catalyzed MCR.
Scheme 92: Synthesis of chromenoannulated imidazo[1,2-a]pyridines.
Scheme 93: Mechanism for the synthesis of chromeno-annulated IPs.
Scheme 94: Zinc oxide NRs-catalyzed synthesis of imidazo[1,2-a]azines/diazines.
Scheme 95: Zinc oxide-catalyzed isocyanide based GBB reaction.
Scheme 96: Reaction pathway for ZnO-catalyzed GBB reaction.
Scheme 97: Mechanistic pathway.
Scheme 98: ZnO NRs-catalyzed MCR for the synthesis of imidazo[1,2-a]azines.
Scheme 99: Ugi type GBB three-component reaction.
Scheme 100: Magnetic NPs-catalyzed synthesis of imidazo[1,2-a]pyridines.
Scheme 101: Regioselective synthesis of 2-alkoxyimidazo[1,2-a]pyridines catalyzed by Fe-SBA-15.
Scheme 102: Plausible mechanistic pathway for the synthesis of 2-alkoxyimidazopyridine.
Scheme 103: Iron-catalyzed synthetic approach.
Scheme 104: Iron-catalyzed aminooxygenation reaction.
Scheme 105: Mechanistic pathway.
Scheme 106: Rh(III)-catalyzed double C–H activation of 2-substituted imidazoles and alkynes.
Scheme 107: Plausible reaction mechanism.
Scheme 108: Rh(III)-catalyzed non-aromatic C(sp2)–H bond activation–functionalization for the synthesis of imid...
Scheme 109: Reactivity and selectivity of different substrates.
Scheme 110: Rh-catalyzed direct C–H alkynylation by Li et al.
Scheme 111: Suggested radical mechanism.
Scheme 112: Scandium(III)triflate-catalyzed one-pot reaction and its mechanism for the synthesis of benzimidazo...
Scheme 113: RuCl3-assisted Ugi-type Groebke–Blackburn condensation reaction.
Scheme 114: C-3 aroylation via Ru-catalyzed two-component reaction.
Scheme 115: Regioselective synthetic mechanism.
Scheme 116: La(III)-catalyzed one-pot GBB reaction.
Scheme 117: Mechanistic approach for the synthesis of imidazo[1,2-a]pyridines.
Scheme 118: Synthesis of imidazo[1,2-a]pyridine using LaMnO3 NPs under neat conditions.
Scheme 119: Mechanistic approach.
Scheme 120: One-pot 3-CR for regioselective synthesis of 2-alkoxy-3-arylimidazo[1,2-a]pyridines.
Scheme 121: Formation of two possible products under optimization of the catalysts.
Scheme 122: Mechanistic strategy for NiFe2O4-catalyzed reaction.
Scheme 123: Two-component reaction for synthesizing imidazodipyridiniums.
Scheme 124: Mechanistic scheme for the synthesis of imidazodipyridiniums.
Scheme 125: CuI-catalyzed arylation of imidazo[1,2-a]pyridines.
Scheme 126: Mechanism for arylation reaction.
Scheme 127: Cupric acetate-catalyzed double carbonylation approach.
Scheme 128: Radical mechanism for double carbonylation of IP.
Scheme 129: C–S bond formation reaction catalyzed by cupric acetate.
Scheme 130: Cupric acetate-catalyzed C-3 formylation approach.
Scheme 131: Control experiments for signifying the role of DMSO and oxygen.
Scheme 132: Mechanism pathway.
Scheme 133: Copper bromide-catalyzed CDC reaction.
Scheme 134: Extension of the substrate scope.
Scheme 135: Plausible radical pathway.
Scheme 136: Transannulation reaction for the synthesis of imidazo[1,5-a]pyridines.
Scheme 137: Plausible reaction pathway for denitrogenative transannulation.
Scheme 138: Cupric acetate-catalyzed C-3 carbonylation reaction.
Scheme 139: Plausible mechanism for regioselective C-3 carbonylation.
Scheme 140: Alkynylation reaction at C-2 of 3H-imidazo[4,5-b]pyridines.
Scheme 141: Two-way mechanism for C-2 alkynylation of 3H-imidazo[4,5-b]pyridines.
Scheme 142: Palladium-catalyzed SCCR approach.
Scheme 143: Palladium-catalyzed Suzuki coupling reaction.
Scheme 144: Reaction mechanism.
Scheme 145: A phosphine free palladium-catalyzed synthesis of C-3 arylated imidazopyridines.
Scheme 146: Palladium-mediated Buchwald–Hartwig cross-coupling reaction.
Figure 7: Structure of the ligands optimized.
Scheme 147: Palladium acetate-catalyzed direct arylation of imidazo[1,2-a]pyridines.
Scheme 148: Palladium acetate-catalyzed mechanistic pathway.
Scheme 149: Palladium acetate-catalyzed regioselective arylation reported by Liu and Zhan.
Scheme 150: Mechanism for selective C-3 arylation of IP.
Scheme 151: Pd(II)-catalyzed alkenylation reaction with styrenes.
Scheme 152: Pd(II)-catalyzed alkenylation reaction with acrylates.
Scheme 153: A two way mechanism.
Scheme 154: Double C–H activation reaction catalyzed by Pd(OAc)2.
Scheme 155: Probable mechanism.
Scheme 156: Palladium-catalyzed decarboxylative coupling.
Scheme 157: Mechanistic cycle for decarboxylative arylation reaction.
Scheme 158: Ligand-free approach for arylation of imidazo[1,2-a]pyridine-3-carboxylic acids.
Scheme 159: Mechanism for ligandless arylation reaction.
Scheme 160: NHC-Pd(II) complex assisted arylation reaction.
Scheme 161: C-3 arylation of imidazo[1,2-a]pyridines with aryl bromides catalyzed by Pd(OAc)2.
Scheme 162: Pd(II)-catalyzed C-3 arylations with aryl tosylates and mesylates.
Scheme 163: CDC reaction for the synthesis of imidazo[1,2-a]pyridines.
Scheme 164: Plausible reaction mechanism for Pd(OAc)2-catalyzed synthesis of imidazo[1,2-a]pyridines.
Scheme 165: Pd-catalyzed C–H amination reaction.
Scheme 166: Mechanism for C–H amination reaction.
Scheme 167: One-pot synthesis for 3,6-di- or 2,3,6-tri(hetero)arylimidazo[1,2-a]pyridines.
Scheme 168: C–H/C–H cross-coupling reaction of IPs and azoles catalyzed by Pd(II).
Scheme 169: Mechanistic cycle.
Scheme 170: Rh-catalyzed C–H arylation reaction.
Scheme 171: Mechanistic pathway for C–H arylation of imidazo[1,2-a]pyridine.
Scheme 172: Rh(III)-catalyzed double C–H activation of 2-phenylimidazo[1,2-a]pyridines and alkynes.
Scheme 173: Rh(III)-catalyzed mechanistic pathway.
Scheme 174: Rh(III)-mediated oxidative coupling reaction.
Scheme 175: Reactions showing functionalization of the product obtained by the group of Kotla.
Scheme 176: Mechanism for Rh(III)-catalyzed oxidative coupling reaction.
Scheme 177: Rh(III)-catalyzed C–H activation reaction.
Scheme 178: Mechanistic cycle.
Scheme 179: Annulation reactions of 2-arylimidazo[1,2-a]pyridines and alkynes.
Scheme 180: Two-way reaction mechanism for annulations reaction.
Scheme 181: [RuCl2(p-cymene)]2-catalyzed C–C bond formation reaction.
Scheme 182: Reported reaction mechanism.
Scheme 183: Fe(III) catalyzed C-3 formylation approach.
Scheme 184: SET mechanism-catalyzed by Fe(III).
Scheme 185: Ni(dpp)Cl2-catalyzed KTC coupling.
Scheme 186: Pd-catalyzed SM coupling.
Scheme 187: Vanadium-catalyzed coupling of IP and NMO.
Scheme 188: Mechanistic cycle.
Scheme 189: Selective C3/C5–H bond functionalizations by mono and bimetallic systems.
Scheme 190: rGO-Ni@Pd-catalyzed C–H bond arylation of imidazo[1,2-a]pyridine.
Scheme 191: Mechanistic pathway for heterogeneously catalyzed arylation reaction.
Scheme 192: Zinc triflate-catalyzed coupling reaction of substituted propargyl alcohols.
β-Hydroxy sulfides and their syntheses
- Mokgethwa B. Marakalala,
- Edwin M. Mmutlane and
- Henok H. Kinfe
Beilstein J. Org. Chem. 2018, 14, 1668–1692, doi:10.3762/bjoc.14.143
- (-CH2X), alkoxy (-CH2O), aryloxy (PhO), aryl (Ph) and alkyl (-CH2) substituents on the epoxide. The virtues of this protocol are the low cost and ready availability of NBS, its moisture and air stability as well as low toxicity. The reaction is characterized by short reaction time, good to high product
Graphical Abstract
Figure 1: Some sulfur-containing natural products.
Figure 2: Some natural products incorporating β-hydroxy sulfide moieties.
Figure 3: Some synthetic β-hydroxy sulfides of clinical value.
Scheme 1: Alumina-mediated synthesis of β-hydroxy sulfides, ethers, amines and selenides from epoxides.
Scheme 2: β-Hydroxy sulfide syntheses by ring opening of epoxides under different Lewis and Brønsted acid and...
Scheme 3: n-Bu3P-catalyzed thiolysis of epoxides and aziridines to provide the corresponding β-hydroxy and β-...
Scheme 4: Zinc(II) chloride-mediated thiolysis of epoxides.
Scheme 5: Thiolysis of epoxides and one-pot oxidation to β-hydroxy sulfoxides under microwave irradiation.
Scheme 6: Gallium triflate-catalyzed ring opening of epoxides and one-pot oxidation.
Scheme 7: Thiolysis of epoxides and one-pot oxidation to β-hydroxy sulfoxides using Ga(OTf)3 as a catalyst.
Scheme 8: Ring opening of epoxide using ionic liquids under solvent-free conditions.
Scheme 9: N-Bromosuccinimide-catalyzed ring opening of epoxides.
Scheme 10: LiNTf2-mediated epoxide opening by thiophenol.
Scheme 11: Asymmetric ring-opening of cyclohexene oxide with various thiols catalyzed by zinc L-tartrate.
Scheme 12: Catalytic asymmetric ring opening of symmetrical epoxides with t-BuSH catalyzed by (R)-GaLB (43) wi...
Scheme 13: Asymmetric ring opening of meso-epoxides by p-xylenedithiol catalyzed by a (S,S)-(salen)Cr complex.
Scheme 14: Desymmetrization of meso-epoxide with thiophenol derivatives.
Scheme 15: Enantioselective ring-opening reaction of meso-epoxides with ArSH catalyzed by a C2-symmetric chira...
Scheme 16: Enantioselective ring-opening reaction of stilbene oxides with ArSH catalyzed by a C2-symmetric chi...
Scheme 17: Asymmetric desymmetrization of meso-epoxides using BINOL-based Brønsted acid catalysts.
Scheme 18: Lithium-BINOL-phosphate-catalyzed desymmetrization of meso-epoxides with aromatic thiols.
Scheme 19: Ring-opening reactions of cyclohexene oxide with thiols by using CPs 1-Eu and 2-Tb.
Scheme 20: CBS-oxazaborolidine-catalyzed borane reduction of β-keto sulfides.
Scheme 21: Preparation of β-hydroxy sulfides via connectivity.
Scheme 22: Baker’s yeast-catalyzed reduction of sulfenylated β-ketoesters.
Scheme 23: Sodium-mediated ring opening of epoxides.
Scheme 24: Disulfide bond cleavage-epoxide opening assisted by tetrathiomolybdate.
Scheme 25: Proposed reaction mechanism of disulfide bond cleavage-epoxide opening assisted by tetrathiomolybda...
Scheme 26: Cyclodextrin-catalyzed difunctionalization of alkenes.
Scheme 27: Zinc-catalyzed synthesis of β-hydroxy sulfides from disulfides and alkenes.
Scheme 28: tert-Butyl hydroperoxide-catalyzed hydroxysulfurization of alkenes.
Scheme 29: Proposed mechanism of the radical hydroxysulfurization.
Scheme 30: Rongalite-mediated synthesis of β-hydroxy sulfides from styrenes and disulfides.
Scheme 31: Proposed mechanism of Rongalite-mediated synthesis of β-hydroxy sulfides from styrenes and disulfid...
Scheme 32: Copper(II)-catalyzed synthesis of β-hydroxy sulfides 15e,f from alkenes and basic disulfides.
Scheme 33: CuI-catalyzed acetoxysulfenylation of alkenes.
Scheme 34: CuI-catalyzed acetoxysulfenylation reaction mechanism.
Scheme 35: One-pot oxidative 1,2-acetoxysulfenylation of Baylis–Hillman products.
Scheme 36: Proposed mechanism for the oxidative 1,2-acetoxysulfination of Baylis–Hillman products.
Scheme 37: 1,2-Acetoxysulfenylation of alkenes using DIB/KI.
Scheme 38: Proposed reaction mechanism of the diacetoxyiodobenzene (DIB) and KI-mediated 1,2-acetoxysulfenylat...
Scheme 39: Catalytic asymmetric thiofunctionalization of unactivated alkenes.
Scheme 40: Proposed catalytic cycle for asymmetric sulfenofunctionalization.
Scheme 41: Synthesis of thiosugars using intramolecular thiol-ene reaction.
Scheme 42: Synthesis of leukotriene C-1 by Corey et al.: (a) N-(trifluoroacetyl)glutathione dimethyl ester (3 ...
Scheme 43: Synthesis of pteriatoxins with epoxide thiolysis to attain β-hydroxy sulfides. Reagents: (a) (1) K2...
Scheme 44: Synthesis of peptides containing a β-hydroxy sulfide moiety.
Scheme 45: Synthesis of diltiazem (12) using biocatalytic resolution of an epoxide followed by thiolysis.
Synthesis and in vitro biochemical evaluation of oxime bond-linked daunorubicin–GnRH-III conjugates developed for targeted drug delivery
- Sabine Schuster,
- Beáta Biri-Kovács,
- Bálint Szeder,
- Viktor Farkas,
- László Buday,
- Zsuzsanna Szabó,
- Gábor Halmos and
- Gábor Mező
Beilstein J. Org. Chem. 2018, 14, 756–771, doi:10.3762/bjoc.14.64
- plastic culture dishes at 37 °C with a humidified atmosphere containing 5% CO2/95% air. Stability of GnRH-III bioconjugates in cell culture medium The GnRH-III bioconjugates were dissolved in water to a concentration of 2.5 mg/mL followed by the dilution with serum-free cell culture medium (final
Graphical Abstract
Scheme 1: Syntheses of GnRH-III–[(4Lys(Bu)/4Ser, 6Aaa, 8Lys(Dau=Aoa)] bioconjugates. a) (1) 2% hydrazine in D...
Figure 1: Far-UV ECD spectra of GnRH-III and its drug conjugates in water (GnRH-III solid, K1 dash, K2 dot, 1...
Figure 2: Degradation of the GnRH-III bioconjugates by rat liver lysosomal homogenate. A) Cleavage sites prod...
Figure 3: Cytostatic effect of the GnRH-III bioconjugates at different concentrations on A) HT-29 and B) MCF-...
Figure 4: Cellular uptake of the GnRH-III bioconjugates at different concentrations on A) HT-29 and B) MCF-7 ...
Figure 5: Cellular uptake of bioconjugate K2 (40 µM) visualized by confocal laser scanning microscopy (CLSM) ...
Figure 6: Competitive inhibition of the GnRH-R on MCF-7 cells. Cellular uptake of the GnRH-III bioconjugate K2...
Synthesis and characterization of benzodithiophene and benzotriazole-based polymers for photovoltaic applications
- Desta Gedefaw,
- Marta Tessarolo,
- Margherita Bolognesi,
- Mario Prosa,
- Renee Kroon,
- Wenliu Zhuang,
- Patrik Henriksson,
- Kim Bini,
- Ergang Wang,
- Michele Muccini,
- Mirko Seri and
- Mats R. Andersson
Beilstein J. Org. Chem. 2016, 12, 1629–1637, doi:10.3762/bjoc.12.160
- devices with a high open circuit voltage (VOC), according to the difference LUMOACCEPTOR − HOMODONOR [28]. Good air stability is also expected from these polymers as their HOMO energies are in an ideal range [29]. On the other hand, the slightly raised LUMO observed in both polymers is expected due to the
Graphical Abstract
Scheme 1: Stille cross coupling reaction for the synthesis of PTzBDT-1 and PTzBDT-2.
Figure 1: UV–visible absorption spectra of the pristine PTzBDT-1 and PTzBDT-2 (A) in chlorobenzene and chloro...
Figure 2: Square wave voltamogramme of PTzBDT-1 and PTzBDT-2.
Figure 3: J–V plots, measured under standard illumination (AM1.5G, 100 mW/cm2), of PTzBDT-1: PC61BM and PTzBD...
Figure 4: A) UV–vis absorption spectra and, B) EQE plots of optimized PTzBDT-1/PTzBDT-2:PC61BM based devices.
Figure 5: AFM images (size: 5 µm × 5 µm) of: A) 1:2 (wt/wt) PTzBDT-1:PC61BM (RMS of ~1.5 nm) and, B) 1:1 (wt/...
Dinuclear thiazolylidene copper complex as highly active catalyst for azid–alkyne cycloadditions
- Anne L. Schöffler,
- Ata Makarem,
- Frank Rominger and
- Bernd F. Straub
Beilstein J. Org. Chem. 2016, 12, 1566–1572, doi:10.3762/bjoc.12.151
- of the complex’s properties and its features according to specific demands. Dicopper complexes with thiazolylidene ancillary ligands provide for improved availability, air-stability and convenience for the growing community of CuAAC users. Experimental General methodology All reactions were carried
Graphical Abstract
Scheme 1: Disfavored mononuclear pathway and favored dinuclear pathway in the CuAAC click reaction, according...
Figure 1: Ball-and-stick model [42,43] of a single crystal X-ray structure of hexafluorophosphate salt 1b (CCDC 1472...
Scheme 2: Synthesis of dinuclear copper complex 2.
Figure 2: Time-conversion-diagram of the CuAAC reaction of benzyl azide with either phenylacetylene or ethyl ...
Syntheses of dibenzo[d,d']benzo[2,1-b:3,4-b']difuran derivatives and their application to organic field-effect transistors
- Minh Anh Truong and
- Koji Nakano
Beilstein J. Org. Chem. 2016, 12, 805–812, doi:10.3762/bjoc.12.79
- [2,1-b:3,4-b']difuran (syn-DBBDF 5) and dinaphtho[2,3-d:2',3'-d']benzo[2,1-b:3,4-b']difuran (syn-DNBDF 6). Based on the photophysical and electrochemical data, both compounds are expected to possess good air stability as organic semiconducting materials. The comparison with their anti-isomers revealed
Graphical Abstract
Figure 1: Structures of furan-fused ladder-type π-conjugated compounds.
Scheme 1: Synthesis of syn-DBBDF 5.
Scheme 2: Synthesis of syn-DNBDF 6.
Figure 2: (a) DSC and (b) TG curves of syn-DBBDF 5 and syn-DNBDF 6.
Figure 3: (a) UV–vis absorption spectra of syn-DBBDF 5 (blue line) and syn-DNBDF 6 (red line) in CHCl3 (1.0 ×...
Figure 4: Cyclic voltammograms of syn-DBBDF 5 and syn-DNBDF 6 (measurement conditions: 1.0 mM in CH2Cl2 for s...
Figure 5: Output and transfer characteristics of the representative OFETs with a thin film of (a) syn-DBBDF 5...
Figure 6: (a) XRD pattern, (b) AFM image (2 × 2 μm), and (c) cross-section height of a thin film of syn-DNBDF ...
Olefin metathesis in air
- Lorenzo Piola,
- Fady Nahra and
- Steven P. Nolan
Beilstein J. Org. Chem. 2015, 11, 2038–2056, doi:10.3762/bjoc.11.221
- metathesis, the evolution of metathesis catalysts towards air stability has become an area of significant interest. In this fascinating area of study, beginning with early systems making use of high oxidation state early transition metal centers that required strict exclusion of water and air, advances have
- been made to render catalysts more stable and yet more functional group tolerant. This review summarizes the major developments concerning catalytic systems directed towards water and air tolerance. Keywords: air stability; catalysis; olefin metathesis; RCM; ROMP; ruthenium; Introduction Transition
- . Due to air stability, their activity in nondegassed DCM, toluene and ACS grade ethyl acetate was reported (Table 3). Complex 76b performed slightly better in all cases, regardless of the air atmosphere and of the solvent used. With low catalyst loadings, ranging from 1 to 0.1 mol %, high to
Graphical Abstract
Scheme 1: Polymerization of 7-oxanorbornene in water.
Scheme 2: Synthesis of the first well-defined ruthenium carbene.
Scheme 3: Synthesis of Grubbs' 1st generation catalyst.
Figure 1: NHC-Ruthenium complexes and widely used NHC carbenes.
Scheme 4: Access to 21 from the Grubbs’ 1st generation catalyst and its one-pot synthesis.
Scheme 5: Synthesis of supported Hoveyda-type catalyst.
Figure 2: Scope of RCM reactions with supported Hoveyda-type catalyst. Reaction conditions: 24 (5 mol %), non...
Scheme 6: Synthesis of 33 by Hoveyda and Blechert.
Figure 3: Synthesis of chiral Hoveyda–Grubbs type catalyst and its use in RO/CM.
Scheme 7: Synthesis of 41.
Figure 4: RCM reactions in air using 41 as catalyst. Reaction conditions: 41 (5 mol %), MeOH (0.05 M), 22 °C,...
Figure 5: CM-type reactions in air using 41 as catalyst. Reaction conditions: 41 (5 mol %), 22 °C, 12 h, in a...
Figure 6: Grela's complex (54) and reaction scope in air. Reaction conditions: catalyst, substrate (0.25 mmol...
Figure 7: Abell's complex (61) and its RCM reaction scope in air. Reaction condition: 10 mol % of 61, refluxi...
Figure 8: Catalysts used by Meier in air.
Figure 9: Ammonium chloride-tagged complexes.
Figure 10: Scorpio-type complexes.
Scheme 8: Synthesis of Grubbs' 3rd generation catalyst.
Figure 11: Indenylidene complexes.
Figure 12: Commercially available complexes evaluated under air.
Figure 13: Grela's N,N-unsymmetrically substituted complexes.
Scheme 9: Synthesis of phosphite-based catalysts.
Figure 14: Catalysts used by the Cazin group.
Figure 15: RCM scope in air with catalysts 33, 85 and 98a. Reaction conditions: Catalyst, substrate (0.25 mmol...
Figure 16: Synthesis of Schiff base-ruthenium complexes.
Scheme 10: Schiff base–ruthenium complexes synthesized by Verpoort.
Scheme 11: Synthesis of mixed Schiff base–NHC complexes.
Figure 17: Veerport's indenylidene Schiff-base complexes.
First chemoenzymatic stereodivergent synthesis of both enantiomers of promethazine and ethopropazine
- Paweł Borowiecki,
- Daniel Paprocki and
- Maciej Dranka
Beilstein J. Org. Chem. 2014, 10, 3038–3055, doi:10.3762/bjoc.10.322
- - and air-stability make tandem chemoenzymatic processes attractive for both: laboratory and industrial applications. Since enzyme-catalyzed processes provide an access to enantiomerically enriched compounds, they became an extremely practical tool for chemistry and biotechnology [14][15][16][17][18][19
Graphical Abstract
Scheme 1: Chemoenzymatic synthesis of enantioenriched enantiomers of promethazine 9 and ethopropazine 10. Rea...
Figure 1: Dependence of optical purities (% ee) of (R)-(−)-6a (red curve, ■) and (S)-(+)-5 (blue curve, ▲) on...
Scheme 2: Assignment of the stereochemistry of enantiopure alcohol (+)-5 resulting from derivatization with (R...
Figure 2: Description of substituents for determination of the absolute configuration of (+)-5 and ΔδRS value...
Figure 3: 1H NMR (CDCl3, 400 MHz) spectra of the (R)-MPA 11 (red colored line) and (S)-MPA and 12 (blue color...
Figure 4: An ORTEP plot of (S)-(+)-1-(10H-phenothiazin-10-yl)propan-2-ol (S)-(+)-5. The following crystal str...
Scheme 3: Amination of optically active bromo derivatives (R)-(+)-8 or (S)-(−)-8 in toluene.
Scheme 4: Amination of optically active bromo derivatives (R)-(+)-8 or (S)-(−)-8 in methanol.
Scheme 5: The proposed reaction mechanism for amination of optically active (S)-(−)-8 in methanol.
Chiral phosphines in nucleophilic organocatalysis
- Yumei Xiao,
- Zhanhu Sun,
- Hongchao Guo and
- Ohyun Kwon
Beilstein J. Org. Chem. 2014, 10, 2089–2121, doi:10.3762/bjoc.10.218
- of up to >20:1 (Scheme 9) [44][45]. The bulky ferrocene was presumably responsible for the high enantioselectivities. Notably, the presence of the electron-rich ferrocene unit inhibited oxidation of the phosphines, imparting them with air-stability and easy-to-handle properties [45]. Subsequently
Graphical Abstract
Figure 1: Cyclic chiral phosphines based on bridged-ring skeletons.
Figure 2: Cyclic chiral phosphines based on binaphthyl skeletons.
Figure 3: Cyclic chiral phosphines based on ferrocene skeletons.
Figure 4: Cyclic chiral phosphines based on spirocyclic skeletons.
Figure 5: Cyclic chiral phosphines based on phospholane ring skeletons.
Figure 6: Acyclic chiral phosphines.
Figure 7: Multifunctional chiral phosphines based on binaphthyl skeletons.
Figure 8: Multifunctional chiral phosphines based on amino acid skeletons.
Scheme 1: Asymmetric [3 + 2] annulations of allenoates with electron-deficient olefins, catalyzed by the chir...
Scheme 2: Asymmetric [3 + 2] annulations of allenoate and enones, catalyzed by the chiral binaphthyl-based ph...
Scheme 3: Asymmetric [3 + 2] annulations of N-substituted olefins and allenoates, catalyzed by the chiral bin...
Scheme 4: Asymmetric [3 + 2] annulations of 2-aryl-1,1-dicyanoethylenes with ethyl allenoate, catalyzed by th...
Scheme 5: Asymmetric [3 + 2] annulations of 3-alkylideneindolin-2-ones with ethyl allenoate, catalyzed by the...
Scheme 6: Asymmetric [3 + 2] annulations of 2,6-diarylidenecyclohexanones with allenoates, catalyzed by the c...
Scheme 7: Asymmetric [3 + 2] annulations of allenoate with alkylidene azlactones, catalyzed by the chiral bin...
Scheme 8: Asymmetric [3 + 2] annulations of C60 with allenoates, catalyzed by the chiral phosphine B6.
Scheme 9: Asymmetric [3 + 2] annulations of α,β-unsaturated esters and ketones with an allenoate, catalyzed b...
Scheme 10: Asymmetric [3 + 2] annulations of exocyclic enones with allenoates, catalyzed by the ferrocene-modi...
Scheme 11: Asymmetric [3 + 2] annulations of enones with an allenylphosphonate, catalyzed by the ferrocene-mod...
Scheme 12: Asymmetric [3 + 2] annulations of 3-alkylidene-oxindoles with ethyl allenoate, catalyzed by the fer...
Scheme 13: Asymmetric [3 + 2] annulations of dibenzylideneacetones with ethyl allenoate, catalyzed by the ferr...
Scheme 14: Asymmetric [3 + 2] annulations of trisubstituted alkenes with ethyl allenoate, catalyzed by the fer...
Scheme 15: Asymmetric [3 + 2] annulations of 2,6-diarylidenecyclohexanones with allenoates, catalyzed by the f...
Scheme 16: Asymmetric [3 + 2] annulations of α,β-unsaturated ketones with ethyl allenoates, catalyzed by the f...
Scheme 17: Asymmetric [3 + 2] annulations of α,β-unsaturated esters with allenoates, catalyzed by the ferrocen...
Scheme 18: Asymmetric [3 + 2] annulations of alkylidene azlactones with allenoates, catalyzed by the chiral sp...
Scheme 19: Asymmetric [3 + 2] annulations of α-trimethylsilyl allenones and electron-deficient olefins, cataly...
Scheme 20: Asymmetric [3 + 2] annulations of α,β-unsaturated ketones with an allenone, catalyzed by the chiral...
Scheme 21: Asymmetric [3 + 2] annulations of cyclic enones with allenoates, catalyzed by the chiral α-amino ac...
Scheme 22: Asymmetric [3 + 2] annulations of arylidenemalononitriles and analogues with an allenoate, catalyze...
Scheme 23: Asymmetric [3 + 2] annulations of α,β-unsaturated esters with an allenoate, catalyzed by the chiral...
Scheme 24: Asymmetric [3 + 2] annulations of 3,5-dimethyl-1H-pyrazole-derived acrylamides with an allenoate, c...
Scheme 25: Asymmetric [3 + 2] annulations of maleimides with allenoates, catalyzed by the chiral phosphine H10....
Scheme 26: Asymmetric [3 + 2] annulations of α-substituted acrylates with allenoate, catalyzed by the chiral p...
Scheme 27: Asymmetric [3 + 2] annulation of an N-tosylimine with an allenoate, catalyzed by the chiral phosphi...
Scheme 28: Asymmetric [3 + 2] annulations of N-tosylimines with an allenoate, catalyzed by the chiral phosphin...
Scheme 29: Asymmetric [3 + 2] annulations of N-tosylimines with an allenoate, catalyzed by the chiral phosphin...
Scheme 30: Asymmetric [3 + 2] annulations of N-diphenylphosphinoyl aromatic imines with butynoates, catalyzed ...
Scheme 31: Asymmetric [3 + 2] annulations of N-tosylimines with allenylphosphonates, catalyzed by the chiral p...
Scheme 32: Asymmetric [3 + 2] annulation of an N-tosylimine with an allenoate, catalyzed by the chiral phosphi...
Scheme 33: Asymmetric [3 + 2] annulations of N-diphenylphosphinoyl aromatic imines with allenoates (top), cata...
Scheme 34: Asymmetric [3 + 2] annulation of N-diphenylphosphinoylimines with allenoates, catalyzed by the chir...
Scheme 35: Asymmetric [3 + 2] annulation of an azomethine imine with an allenoate, catalyzed by the chiral pho...
Scheme 36: Asymmetric [3 + 2] annulations between α,β-unsaturated esters/ketones and 3-butynoates, catalyzed b...
Scheme 37: Asymmetric intramolecular [3 + 2] annulations of electron-deficient alkenes and MBH carbonates, cat...
Scheme 38: Asymmetric [3 + 2] annulations of methyleneindolinone and methylenebenzofuranone derivatives with M...
Scheme 39: Asymmetric [3 + 2] annulations of activated isatin-based alkenes with MBH carbonates, catalyzed by ...
Scheme 40: Asymmetric [3 + 2] annulations of maleimides with MBH carbonates, catalyzed by the chiral phosphine ...
Scheme 41: A series of [3 + 2] annulations of various activated alkenes with MBH carbonates, catalyzed by the ...
Scheme 42: Asymmetric [3 + 2] annulations of an alkyne with isatins, catalyzed by the chiral phosphine F1.
Scheme 43: Asymmetric [4 + 2] annulations catalyzed by the chiral phosphine B1.
Scheme 44: Asymmetric [4 + 2] annulations catalyzed by the chiral phosphine H5.
Scheme 45: Asymmetric [4 + 2] annulations catalyzed by the chiral phosphines H13 and H12.
Scheme 46: Asymmetric [4 + 2] annulations catalyzed by the chiral phosphine H6.
Scheme 47: Kerrigan’s [2 + 2] annulations of ketenes with imines, catalyzed by the chiral phosphine B7.
Scheme 48: Asymmetric [4 + 1] annulations, catalyzed by the chiral phosphine G6.
Scheme 49: Asymmetric homodimerization of ketenes, catalyzed by the chiral phosphine F5 and F6.
Scheme 50: Aza-MBH/Michael reactions, catalyzed by the chiral phosphine G1.
Scheme 51: Tandem RC/Michael additions, catalyzed by the chiral phosphine H14.
Scheme 52: Intramolecular tandem RC/Michael addition, catalyzed by the chiral phosphine H15.
Scheme 53: Double-Michael addition, catalyzed by the chiral aminophosphine G9.
Scheme 54: Tandem Michael addition/Wittig olefinations, mediated by the chiral phosphine BIPHEP.
Scheme 55: Asymmetric Michael additions, catalyzed by the chiral phosphines H7, H8, and H9.
Scheme 56: Asymmetric γ-umpolung additions, catalyzed by the chiral phosphine A1.
Scheme 57: Asymmetric γ-umpolung additions, catalyzed by the chiral phosphines E2 and E3.
Scheme 58: Intramolecular γ-additions of hydroxy-2-alkynoates, catalyzed by the chiral phosphine D2.
Scheme 59: Intra-/intermolecular γ-additions, catalyzed by the chiral phosphine D2.
Scheme 60: Intermolecular γ-additions, catalyzed by the chiral phosphines B5 and B3.
Scheme 61: Intermolecular γ-additions, catalyzed by the chiral phosphines E6 and B4.
Scheme 62: Asymmetric allylic substitution of MBH acetates, catalyzed by the chiral phosphine G2.
Scheme 63: Allylic substitutions between MBH acetates or carbonates and an array of nucleophiles, catalyzed by...
Scheme 64: Asymmetric acylation of diols, catalyzed by the chiral phosphines E4 and E5.
Scheme 65: Kinetic resolution of secondary alcohols, catalyzed by the chiral phosphine E8 and E9.
Preparation of phosphines through C–P bond formation
- Iris Wauters,
- Wouter Debrouwer and
- Christian V. Stevens
Beilstein J. Org. Chem. 2014, 10, 1064–1096, doi:10.3762/bjoc.10.106
- the corresponding phosphine–borane complex [16][17]. The phosphine–borane complex is a stable intermediate toward the free phosphine. If necessary the boranato group can be removed by treatment with an excess of amine [18]. However, not all phosphines are prone to oxidation and show good air-stability
Graphical Abstract
Scheme 1: Synthesis of P-stereogenic phosphines 5 using menthylphosphinite borane diastereomers 2.
Scheme 2: Enantioselective synthesis of chiral phosphines 10 with ephedrine as a chiral auxiliary.
Scheme 3: Chlorophosphine boranes 11a as P-chirogenic electrophilic building blocks.
Scheme 4: Monoalkylation of phenylphosphine borane 15 with methyl iodide in the presence of Cinchona alkaloid...
Scheme 5: Preparation of tetraphosphine borane 19.
Scheme 6: Using chiral chlorophosphine-boranes 11b as phosphide borane 20 precursors.
Scheme 7: Nickel-catalyzed cross-coupling (dppe = 1,2-bis(diphenylphosphino)ethane).
Scheme 8: Pd-catalyzed cross-coupling reaction with organophosphorus stannanes 30.
Scheme 9: Copper iodide catalyzed carbon–phosphorus bond formation.
Scheme 10: Thermodynamic kinetic resolution as the origin of enantioselectivity in metal-catalyzed asymmetric ...
Scheme 11: Ru-catalyzed asymmetric phosphination of benzyl and alkyl chlorides 35 with HPPhMe (36a, PHOX = pho...
Scheme 12: Pt-catalyzed asymmetric alkylation of secondary phosphines 36b.
Scheme 13: Different adducts 43 can result from hydrophosphination.
Scheme 14: Pt-catalyzed asymmetric hydrophosphination.
Scheme 15: Intramolecular hydrophosphination of phosphinoalkene 47.
Scheme 16: Organocatalytic asymmetric hydrophosphination of α,β-unsaturated aldehydes 59.
Scheme 17: Preparation of phosphines using zinc organometallics.
Scheme 18: Preparation of alkenylphosphines 71a from alkenylzirconocenes 69 (dtc = N,N-diethyldithiocarbamate,...
Scheme 19: SNAr with P-chiral alkylmethylphosphine boranes 13c.
Scheme 20: Synthesis of QuinoxP 74 (TMEDA = tetramethylethylenediamine).
Scheme 21: Pd-Mediated couplings of a vinyl triflate 76 with diphenylphosphine borane 13e.
Figure 1: Menthone (83) and camphor (84) derived chiral phosphines.
Scheme 22: Palladium-catalyzed cross-coupling reaction of vinyl tosylates 85 and 87 with diphenylphosphine bor...
Scheme 23: Attempt for the enantioselective palladium-catalyzed C–P cross-coupling reaction between an alkenyl...
Scheme 24: Enol phosphates 88 as vinylic coupling partners in the palladium-catalyzed C–P cross-coupling react...
Scheme 25: Nickel-catalyzed cross-coupling in the presence of zinc (dppe = 1,2-bis(diphenylphosphino)ethane).
Scheme 26: Copper-catalyzed coupling of secondary phosphines with vinyl halide 94.
Scheme 27: Palladium-catalyzed cross-coupling of aryl iodides 97 with organoheteroatom stannanes 30.
Scheme 28: Synthesis of optically active phosphine boranes 100 by cross-coupling with a chiral phosphine boran...
Scheme 29: Palladium-catalyzed P–C cross-coupling reactions between primary or secondary phosphines and functi...
Scheme 30: Enantioselective synthesis of a P-chirogenic phosphine 108.
Scheme 31: Enantioselective arylation of silylphosphine 110 ((R,R)-Et-FerroTANE = 1,1'-bis((2R,4R)-2,4-diethyl...
Scheme 32: Nickel-catalyzed arylation of diphenylphosphine 25d.
Scheme 33: Nickel-catalyzed synthesis of (R)-BINAP 116 (dppe = 1,2-bis(diphenylphosphino)ethane, DABCO = 1,4-d...
Scheme 34: Nickel-catalyzed cross-coupling between aryl bromides 119 and diphenylphosphine (25d) (dppp = 1,3-b...
Scheme 35: Stereocontrolled Pd(0)−Cu(I) cocatalyzed aromatic phosphorylation.
Scheme 36: Preparation of alkenylphosphines by hydrophosphination of alkynes.
Scheme 37: Palladium and nickel-catalyzed addition of P–H to alkynes 125a.
Scheme 38: Palladium-catalyzed asymmetric hydrophosphination of an alkyne 128.
Scheme 39: Ruthenium catalyzed hydrophosphination of propargyl alcohols 132 (cod = 1,5-cyclooctadiene).
Scheme 40: Cobalt-catalyzed hydrophosphination of alkynes 134a (acac = acetylacetone).
Scheme 41: Tandem phosphorus–carbon bond formation–oxyfunctionalization of substituted phenylacetylenes 125c (...
Scheme 42: Organolanthanide-catalyzed intramolecular hydrophosphination/cyclization of phosphinoalkynes 143.
Scheme 43: Hydrophosphination of alkynes 134c catalyzed by ytterbium-imine complexes 145 (hmpa = hexamethylpho...
Scheme 44: Calcium-mediated hydrophosphanylation of alkyne 134d.
Scheme 45: Formation and substitution of bromophosphine borane 151.
Scheme 46: General scheme for a nickel or copper catalyzed cross-coupling reaction.
Scheme 47: Copper-catalyzed synthesis of alkynylphosphines 156.
Study of thioglycosylation in ionic liquids
- Jianguo Zhang and
- Arthur Ragauskas
Beilstein J. Org. Chem. 2006, 2, No. 12, doi:10.1186/1860-5397-2-12
- volatile organic solvents that have broader environmental concerns.[3] These drawbacks have been well documented and have driven, in part, the quest for alternative solvent systems. Ionic liquids possess several attractive properties such as, no measurable vapor pressure, nonflammable, water and air
- stability, along with enhanced chemical and thermal stability properties. Recent reports have highlighted the potential of ionic liquids to be used as an ideal solvent for acetylation, ortho-esterification and benzylidenation of sugars,[4][5][6] and for certain glycosylation reactions. Sasaki et al
Graphical Abstract
Figure 1: Structures of common ionic liquids.
Scheme 1: Glycosylation of 1 and 2 with various glycosyl donors.
