KIO<sub>3</sub>-catalyzed cross dehydrogenative coupling reaction: sulfenylation of phenol and arylamine derivatives in water at room temperature
作者:Dulin Kong、Tiao Huang、Min Liang、Mingshu Wu、Qiang Lin
DOI:10.1039/c8ob02800a
日期:——
A metal-free direct sulfenylation of phenol and arylamine derivatives with various heterocyclic thiols and thiones using a cross dehydrogenative coupling protocol in water at room temperature has been developed. In addition, this chemical method has several advantages including odorless sulfur sources, good functional group tolerance, green solvent, and mild conditions, making it more environmentally
Regioselective Sulfenylation of α′-CH<sub>3</sub> or α′-CH<sub>2</sub> Groups of α,β-Unsaturated Ketones with Heterocyclic Thiols
作者:Yogesh Siddaraju、Kandikere Ramaiah Prabhu
DOI:10.1021/acs.joc.7b03290
日期:2018.3.2
A rare regioselective sulfenylation of α′-CH3 or α′-CH2 bonds adjacent to α,β-unsaturated ketones using dimethyl sulfoxide as an oxidant and a substoichiometric amount of aq HI as an additive is described. This methodology employs a strong acid such as aq HI or iodine and exhibits a high regioselectivity without undergoing conjugate addition, which is difficult to achieve under the cross dehydrogenative
Novel 1-dethia-2-thia-cephalosporanic acid derivatives of the formula ##STR1## wherein R is selected from the group consisting of ##STR2## Ra is an organic radical, R.sub.i and R.sub.j are individually selected from the group consisting of hydrogen, aliphatic, aromatic and heterocycle or taken together with the nitrogen atom to which they are attached form an optionally substituted cycle or R.sub.b NH--, R.sub.b is optionally substituted carbocyclic or heterocyclic aryl, R.sub.1 and --COM are as defined in the specification, R.sub.4 is hydrogen or methoxy, n.sub.2 is 0, 1 or 2 and their non-toxic, pharmaceutically acceptable acid addition salts in racemic or optically active form having antibiotic activity and their preparation and novel intermediates.
Redox chemistry between graphene oxide and mercaptan
作者:Deqin Fan、Chao Zhang、Junpo He、Rong Hua、Yang Zhang、Yuliang Yang
DOI:10.1039/c2jm33467d
日期:——
We report here redox reactions between graphene oxide (GO) and mercaptans, which reduces GO to reduced graphene oxide (RGO) and oxidizes mercaptans into disulfides. The reduction processes of GO using various mercaptans as the reducing agents are investigated through XPS, TGA, FT-IR, Raman and EA analysis. The degree of reduction of RGO depends on molecular structure of mercaptans and is controlled by the reaction time. The redox reaction is also employed to oxidize mercaptans into disulfides in medium to high yields under moderate conditions. The mechanism of the redox reaction may involve nucleophilic ring opening of oxirane on GO by alkylthio moiety, followed by addition of another alkylthio group, leaving the resulting disulfide. The reduction of the hydroxy group could be more complex, involving both radical and anionic processes.
Mesoionic 1,3-dialkyltetrazolium-5-thiolates can be prepared in good yields by alkylation of 1-alkyltetrazole-5-thiols with secondary alcohols in concentrated sulfuric acid. The thiolates are transformed into the corresponding olates through S-alkylation followed by hydrolysis. The olates were found to be liquid at room temperature and to work effectively as polar solvents. The use of a smaller amount