Enantioselective thiourea-catalyzed additions to oxocarbenium ions.

ABSTRACT: Asymmetric, catalytic reactions of oxocarbenium ions are reported. Simple, chiral urea and thiourea derivatives are shown to catalyze the enantioselective substitution of silyl ketene acetals onto 1-chloroisochromans. A mechanism involving anion binding by the chiral catalyst to generate a reactive oxocarbenium ion is invoked. Catalysts bearing tertiary benzylic amide groups afforded highest enantioselectivities, with the optimal structure being derived from enantioenriched 2-arylpyrrolidine derivatives.

SUBMITTER: Reisman SE 

PROVIDER: S-EPMC2574628 | biostudies-literature | 2008 Jun

REPOSITORIES: biostudies-literature