Photochemical anion-promoted carbon-sulfur cleavage reactions of diaryl sulfides, alkyl aryl sulfides and related sulfoxides and sulfones
摘要:
Diaryl sulfides and the related sulfoxides and sulfones react with substances such as diethyl phosphite anion, pinacolone enolate, and diphenylphosphide anion under irradiation to cleave one carbon-sulfur bond and form diethyl arylphosphonates, arylmethyl tert-butyl ketones, and aryldiphenylphosphines. Alkyl aryl sulfides and the related sulfones also experience carbon-sulfur bond cleavage under these conditions to produce arenethiols. Generally, these reactions occur in synthetically useful yields. The reactions of the anions with these sulfides, sulfoxides, and sulfones all require irradiation, but it is notable that the reactions of diphenylphosphide anion occur in the visible region of the spectrum. Several lines of evidence suggest that the reaction proceeds via the familiar S(RN)1 pathway and that the photochemically-induced electron transfer occurs in an arene-anion complex. Thermochemical considerations dictate the cleavage direction in the anion radicals of unsymmetrical sulfides.
Copper nanoparticles supported on polyaniline-functionalized multiwall carbon nanotubes: An efficient and recyclable catalyst for synthesis of unsymmetric sulfides using potassium ethyl xanthogenate in water
作者:Abdol R. Hajipour、Saeideh Jajarmi、Zahra Khorsandi
DOI:10.1002/aoc.3697
日期:2017.9
polyaniline‐functionalized carbon nanotube‐supported copper(II) nanoparticle catalyst was successfully prepared and evaluated as a heterogeneous catalyst for the one‐pot synthesis of unsymmetricthioethers by coupling of aryl, alkyl and benzylhalidesusing potassium ethyl xanthogenate as source of sulfur in water. All of these reactions gave the desired products in good to excellent yields. The catalyst is available
Biomedical devices such as contact lenses formed from a polymerization product of a mixture comprising (a) a hydrophilic polymer comprising one or more hydrophilic units and one or more thio carbonyl thio fragments of a reversible addition fragmentation chain transfer (“RAFT”) agent; and (b) one or more biomedical device-forming monomers are disclosed.