Catalytic applications of F8BINOL: asymmetric oxidation of sulfides to sulfoxides

The effect of fluorine substitution at the 5, 5', 6, 6', 7, 7', 8 and 8' po sitions of 2,2'-dihydroxy-1,1'-binaphthyl (BINOL) on its catalytic activity in titanium-mediated sulfide oxidation with tert-butyl hydrogen peroxide a nd cumyl hydrogen peroxide was examined. Introduction of fluorines into the BINOL scaffold was found to increase the electrophilic character of the Le wis acidic titanium center of the catalyst. Moreover, under otherwise ident ical conditions, BINOL and 5,5',6,6',7,7',8,8'-octafluoro-2,2'-dihydroxy-1, 1'-binaphthyl (F8BINOL) of the same absolute configuration led to opposite sense of chiral induction in the sulfoxidation process. (C) 2000 Published by Elsevier Science S.A. All rights reserved.