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Asymmetric aza-[3+3] annulation in the synthesis of indolizidines: an unexpected reversal of regiochemistry.

ABSTRACT: An enantioselective and diastereoselective aza-[3+3] annulation of pyrrolidine-based exo-cyclic vinylogous amides and urethanes with chiral vinyl iminium salts is described. This asymmetric annulation manifold is possible because of an unexpected regiochemical reversal whereby head-to-tail annulations dominated over the predicted head-to-head. It should find prevalent synthetic applications in the enantioselective synthesis of indolizidines.

SUBMITTER: Buchanan GS

PROVIDER: S-EPMC3155627 | biostudies-literature | 2011 Aug

REPOSITORIES: biostudies-literature

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Asymmetric aza-[3+3] annulation in the synthesis of indolizidines: an unexpected reversal of regiochemistry.

Buchanan Grant S GS Dai Huifang H Hsung Richard P RP Gerasyuto Aleksey I AI Scheinebeck Casi M CM

Organic letters 20110725 16

An enantioselective and diastereoselective aza-[3+3] annulation of pyrrolidine-based exo-cyclic vinylogous amides and urethanes with chiral vinyl iminium salts is described. This asymmetric annulation manifold is possible because of an unexpected regiochemical reversal whereby head-to-tail annulations dominated over the predicted head-to-head. It should find prevalent synthetic applications in the enantioselective synthesis of indolizidines. ...[more]

PMID: 21786757

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