Synthesis of novel β-amino alcohols and their application in the catalytic asymmetric sulfoxidation of sulfides
摘要:
Novel chiral norephedrine-based beta-amino alcohol ligands containing a thiophene ring were prepared from norephedrine and substituted furan carbaldehydes (methyl- or ethyl-substituted) and used in combination with VO(acac)(2) for the asymmetric oxidation of aryl methyl sulfides using H2O2 as an oxidant. Amino alcohol derived Schiff bases 4,5a-b gave higher enantiomeric excesses than amino alcohol-derived reduced Schiff based ligands 6,7a-b. Of these chiral ligands, (1S,2R)-5b and (1S,2R)-7b gave high yields (90%) with moderate to high enantioselectivities (78%, 96% ee, respectively). The oxidation of other aryl methyl sulfides with (1S,2R)-5b and (1S,2R)-7b as ligands afforded the corresponding sulfoxides in 60-89% yields and with 92-99% ee. (C) 2013 Elsevier Ltd. All rights reserved.
Efficient Asymmetric Oxidation of Sulfides and Kinetic Resolution of Sulfoxides Catalyzed by a Vanadium−Salan System
作者:Jiangtao Sun、Chengjian Zhu、Zhenya Dai、Minghua Yang、Yi Pan、Hongwen Hu
DOI:10.1021/jo040221d
日期:2004.11.1
The asymmetricoxidation of sulfides to chiral sulfoxides with hydrogen peroxide in good yield and high enantioselectivity has been catalyzed very effectively by chiral vanadium−salan [N,N‘-alkyl bis(salicylamine)] complex. The salan ligand shows results superior in terms of reactivity and enantioselectivity to those of salen [N,N‘-alkylene bis(salicylideneimine)] analogue, and provides the sulfoxide
Asymmetricoxidation of sulfides was examined by using (salen)manganese(III) complexes as catalysts and (8S,8′S,1″S,2″S)-complex (3b) was found to show high asymmetric induction up to 90% ee. To be interested, however, (8R,8′R,1″S,2″S)-complex (1a) that showed excellent asymmetric induction in the epoxidation of simple olefins was a poor catalyst for the oxidation of sulfides.
Diastereoselective oxidation of menthyl arenesulfenates to sulfinates and access to enantioenriched aryl methyl sulfoxides
作者:Matthieu Hamel、Michel Vazeux、Mihaela Gulea
DOI:10.1007/s11696-021-01759-9
日期:2021.11
Three aryl methyl sulfoxides were prepared via the following sequence: synthesis of the menthyl arenesulfenate from the corresponding thiol, diastereoselective oxidation leading to the sulfinate, then reaction with a Grignard reagent. The aryl moiety was substituted with a methyl ester on the ortho position or a nitro group on the ortho or the para position. The sulfenate esters were obtained in fair