Enantiopure thiosulfonium salts in asymmetric synthesis. Face selectivity in electrophilic additions to unfunctionalised olefins
Abstract
Enantiopure S-methylthiodinaphtho[2,1-c: 1′,2′-e][1,2]dithiinium hexachloroantimonate 3, transfers enantioselectively the MeS+ group to trans-hex-3-ene, leading to non-racemic thiiranium ion 4, which, in turn, reacts with MeCN–H2O allowing the synthesis of optically active double functionalised alkanes with enantiomeric excesses of up to 86%.