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Search for "thiocarbonates" in Full Text gives 4 result(s) in Beilstein Journal of Organic Chemistry.
Generation of alkyl and acyl radicals by visible-light photoredox catalysis: direct activation of C–O bonds in organic transformations
- Mithu Roy,
- Bitan Sardar,
- Itu Mallick and
- Dipankar Srimani
Beilstein J. Org. Chem. 2024, 20, 1348–1375, doi:10.3762/bjoc.20.119
- radicals by activation of C–O bonds using visible-light photoredox catalysis offers a mild and environmentally benign approach to useful chemical transformations. Alcohols, carboxylic acids, anhydrides, xanthates, oxalates, N-phthalimides, and thiocarbonates are some examples of alkyl and acyl precursors
- , epiandrosterone, hecogenin, rockogenin, and tigogenin. All of them were successfully converted into boronic esters with high diastereoselectivity. In 2021, Cook and co-workers [45] unveiled the photomediated trifluoromethylation of alcohols by converting alcohols into thiocarbonates (Scheme 8). This copper
- -mediated deoxygenative trifluoromethylation technique worked with both benzylic and unactivated thiocarbonates. The proposed mechanism starts with the homolysis of (bpy)Cu(III)(CF3)3 by blue-light irradiation, which produces CF3 radicals and (bpy)Cu(II)(CF3)2. Subsequently, the interaction between the CF3
Graphical Abstract
Figure 1: Generation of alkyl and acyl radicals via C–O bond breaking.
Figure 2: General photocatalytic mechanism.
Scheme 1: Photoredox-catalyzed hydroacylation of olefins with aliphatic carboxylic acids.
Scheme 2: Acylation–aromatization of p-quinone methides using carboxylic acids.
Scheme 3: Visible-light-induced deoxygenation–defluorination for the synthesis of γ,γ-difluoroallylic ketones....
Scheme 4: Photochemical hydroacylation of azobenzenes with carboxylic acids.
Scheme 5: Photoredox-catalyzed synthesis of flavonoids.
Scheme 6: Synthesis of O-thiocarbamates and photocatalytic reduction of O-thiocarbamates.
Scheme 7: Deoxygenative borylation of alcohols.
Scheme 8: Trifluoromethylation of O-alkyl thiocarbonyl substrates.
Scheme 9: Redox-neutral radical coupling reactions of alkyl oxalates and Michael acceptors.
Scheme 10: Visible-light-catalyzed and Ni-mediated syn-alkylarylation of alkynes.
Scheme 11: 1,2-Alkylarylation of alkenes with aryl halides and alkyl oxalates.
Scheme 12: Deoxygenative borylation of oxalates.
Scheme 13: Coupling of N-phthalimidoyl oxalates with various acceptors.
Scheme 14: Cross-coupling of O-alkyl xanthates with aryl halides via dual photoredox and nickel catalysis.
Scheme 15: Deoxygenative borylation of secondary alcohol.
Scheme 16: Deoxygenative alkyl radical generation from alcohols under visible-light photoredox conditions.
Scheme 17: Deoxygenative alkylation via alkoxy radicals against hydrogenation or β-fragmentation.
Scheme 18: Direct C–O bond activation of benzyl alcohols.
Scheme 19: Deoxygenative arylation of alcohols using NHC to activate alcohols.
Scheme 20: Deoxygenative conjugate addition of alcohol using NHC as alcohol activator.
Scheme 21: Synthesis of polysubstituted aldehydes.
Electrochemical Corey–Winter reaction. Reduction of thiocarbonates in aqueous methanol media and application to the synthesis of a naturally occurring α-pyrone
- Ernesto Emmanuel López-López,
- José Alvano Pérez-Bautista,
- Fernando Sartillo-Piscil and
- Bernardo A. Frontana-Uribe
Beilstein J. Org. Chem. 2018, 14, 547–552, doi:10.3762/bjoc.14.41
- more environmentally friendly than the classical reaction, where a large excess of trialkyl phosphite as reducing agent and high temperatures are required. Thus, cathodic reduction at room temperature of two cyclic thiocarbonates (−1.2 to −1.4 V vs Ag/AgCl) afforded the corresponding alkenes, trans-6
- ; thiocarbonates; Findings The Corey–Winter reaction (also known as the Corey–Winter reductive olefination) is a chemical transformation that permits the conversion of 1,2-diols A into E-alkenes C via the formation and reduction of a cyclic thiocarbonate intermediate B (Scheme 1) [1][2]. In general this reaction
- molecule 5. In this letter we report the electrochemical behavior of thiocarbonates 4 and 6 in aqueous methanol MeOH/H2O (80:20) with 0.5 M AcOH/AcONa buffer as supporting electrolyte, as well as the results of several reductive electrolysis performed under green chemistry conditions. Cyclic thiocarbonate
Graphical Abstract
Scheme 1: The Corey–Winter reaction in general.
Scheme 2: Proposed route for the synthesis of metabolites isolated from Trichoderma and Penicillium species f...
Scheme 3: Preparation of thiocarbonate precursor 6 from pyrone dioxolane 7.
Figure 1: Cyclic voltammetry of thiocarbonates 4 (left) and 6 (right); c = 1 × 10−3 M, N2 bubbling 5 min, WE ...
Scheme 4: Putative reaction mechanism of the electrochemical Corey–Winter reaction.
The selective electrochemical fluorination of S-alkyl benzothioate and its derivatives
- Shunsuke Kuribayashi,
- Tomoyuki Kurioka,
- Shinsuke Inagi,
- Ho-Jung Lu,
- Biing-Jiun Uang and
- Toshio Fuchigami
Beilstein J. Org. Chem. 2018, 14, 389–396, doi:10.3762/bjoc.14.27
- and ethyl thiocyanates as well as O-methyl S-aralkyl thiocarbonates by using the anodically stable Et3N·5HF and Et4NF·4HF [21][22]. In both cases, an EWG attached to the phenyl group and the electron-withdrawing SCN group both contribute to the generation of the cation resulting in a regioselective α
Graphical Abstract
Figure 1: Cyclic voltammograms of 0.1 M Bu4NBF4/MeCN with a Pt disk working electrode in the absence (brown l...
Figure 2: Calculated HOMO diagram of 1a.
Figure 3: Calculated HOMO diagrams of 1h, 1i and 1j.
Scheme 1: Plausible reaction paths of the anodic oxidation of 1i in Et4NF·4HF/CH2Cl2.
Scheme 2: Anodic fluorination of 1k.
Scheme 3: Anodic fluorination of cyclic derivative 1l.
Scheme 4: Anodic oxidation of 1m and 1n in Et4NF·4HF/CH2Cl2.
Scheme 5: General reaction mechanism for the anodic fluorination of 1.
Scheme 6: Reaction mechanism for the anodic oxidation of carboxylic acids 1m and 1n in the presence of a fluo...
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
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.
