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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

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Enantioselective thiourea-catalyzed additions to oxocarbenium ions.

Reisman Sarah E SE Doyle Abigail G AG Jacobsen Eric N EN

Journal of the American Chemical Society 20080514 23

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 der ...[more]

PMID: 18479086

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