Investigation of steric and electronic effects in the copper-catalysed asymmetric oxidation of sulfides
作者:Graham E. O'Mahony、Kevin S. Eccles、Robin E. Morrison、Alan Ford、Simon E. Lawrence、Anita R. Maguire
DOI:10.1016/j.tet.2013.08.063
日期:2013.11
in the copper-catalysed asymmetricoxidation of aryl benzyl, aryl alkyl and alkyl benzyl sulfides have been investigated. The presence of an aryl group directly attached to the sulfur is essential to afford sulfoxides with high enantioselectivities, with up to 97% ee for 2-naphthyl benzyl sulfoxide, the highest enantioselectivity achieved to date for copper-catalysed asymmetric sulfoxidation. In contrast
A one-potsynthesis of aryl sulfones from primary alcohols is described. Alcohols were treated with N-bromosuccinimide and triphenylphosphine, followed by addition of sodium arenesulfinate with a catalytic amount of tetrabutylammonium iodide to afford the aryl sulfones in good to high yields.
Cyanide-Mediated Synthesis of Sulfones and Sulfonamides from Vinyl Sulfones
作者:Tamal Roy、Ji-Woong Lee
DOI:10.1055/s-0039-1690991
日期:2020.3
We report a facile synthesis of sulfones, β-keto sulfones, and sulfonamides from vinyl sulfones via an addition–elimination sequence where in situ generation of nucleophilic sulfinate ion is mediated by cyanide. The use vinyl sulfones renders high selectivity for S-alkylation to produce sulfones in high yields. In the presence of N-bromosuccinimide, primary and secondary amines underwent sulfonamide
Various α-sulfonylcarbanions have been shown to react at low temperature with di- or tri-halogenolithiocarbenoïds, to give 1-mono- or 1,1-di-halogenoalkenes. Bromocarbenoïds gave better results than their chloro-analogues. Reaction of di-bromolithiomethane with α-lithiated sulfones gives a high yield of vinylic bromides, the stereochemistry of which is cleanly E. Evidence is presented that the carbenoïd
Hydrosulfonylation of Unactivated Alkenes by Visible Light Photoredox Catalysis
作者:Juan-Juan Wang、Wei Yu
DOI:10.1021/acs.orglett.9b03636
日期:2019.11.15
hydrosulfonylation of unactivated alkenes with sodium sulfinates was realized via [Ir(dF(CF3)ppy)2(dtbbpy)]PF6-mediated visiblelightphotoredoxcatalysis. The presence of an acid such as acetic acid is essential for the reaction to take place. A variety of unactivated alkenes can be transformed into sulfones with good yield and high regioselectivity using this reaction, which is proposed to proceed by a radical