Asymmetric synthesis of chiral sulfoxides and sulfinimines by using N-sulfinylsultam
摘要:
Bornane-10,2-sultam 1 is stereoselectively converted by DMAP-assisted sulfinylation to diastereomerically pure (2R)-N-[(R)-p-tolylsulfinyl]-bornane-10,2-sultam 2 in 77% yield. The crystalline sulfinylating agent 2 reacts with a variety of nucleophiles to afford sulfoxides 3 and sulfinimines 5 in excellent yields and enantioselectivities. (C) 1997 Elsevier Science Ltd.
Catalytic Enantioselective Oxidation of Bulky Alkyl Aryl Thioethers with H2O2 over Titanium-Salan Catalysts
作者:Konstantin P. Bryliakov、Evgenii P. Talsi
DOI:10.1002/ejoc.201100557
日期:2011.8
procedure for the oxidation of bulky (preferably aryl benzyl substituted) thioethers with hydrogen peroxide in good to high yields and enantioselectivities (up to 98.5 % ee) is reported. The high optical yields are achieved in a tandem stereoconvergent enantioselective oxidation and kinetic resolution process. A reasonable balance between the sulfoxide yield and enantioselectivity could be found by varying
Preliminary results concerning a conceptually novel route to chiral sulfoxides based on the asymmetric alkylation of sulfenate salts with alkyl halides mediated by a chiral phase-transfer catalyst are described. As a representative example, o-anisyl methyl sulfoxide was produced in 96% yield and with an enantiomeric excess of 58% using commercial cinchonidinium derivative 2a.
Copper-catalyzed asymmetric sulfoxidation of aryl benzyl and aryl alkyl sulfides, using aqueous hydrogen peroxide as the oxidant, has been investigated. A relationship between the steric effects of the sulfide substituents and the enantioselectivity of the oxidation has been observed, with up to 93% ee for 2-naphthylmethyl phenyl sulfoxide, in modest yield in this instance (up to 30%). The influence
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
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