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Organometallic enantiomeric scaffolding: general access to 2-substituted oxa- and azabicyclo[3.2.1]octenes via a Bronsted acid catalyzed [5 + 2] cycloaddition reaction.

ABSTRACT: 6-Substituted TpMo(CO) 2(eta-2,3,4-pyranyl)- and TpMo(CO) 2(eta-2,3,4-pyridinyl) scaffolds (Tp = hydridotrispyrazolylborato) function as reaction partners in an efficient regio- and stereocontrolled synthesis of functionalized oxa- and azabicyclo[3.2.1]octenes through a novel Brønsted acid catalyzed [5 + 2] cycloaddition reaction. Excellent exo-selectivities are obtained, and the reaction gives products with complete retention of enantiomeric purity when carried out with chiral, nonracemic scaffolds. The substituent at C-6 of the eta (3)-coordinated heterocyclic scaffold not only influences [5 + 2] reactivity but also plays a critical role in the demetalation step directing the reaction to only one of two possible products.

SUBMITTER: Garnier EC

PROVIDER: S-EPMC2757657 | biostudies-literature | 2008 Jun

REPOSITORIES: biostudies-literature

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Organometallic enantiomeric scaffolding: general access to 2-substituted oxa- and azabicyclo[3.2.1]octenes via a Brønsted acid catalyzed [5 + 2] cycloaddition reaction.

Garnier Ethel C EC Liebeskind Lanny S LS

Journal of the American Chemical Society 20080515 23

6-Substituted TpMo(CO) 2(eta-2,3,4-pyranyl)- and TpMo(CO) 2(eta-2,3,4-pyridinyl) scaffolds (Tp = hydridotrispyrazolylborato) function as reaction partners in an efficient regio- and stereocontrolled synthesis of functionalized oxa- and azabicyclo[3.2.1]octenes through a novel Brønsted acid catalyzed [5 + 2] cycloaddition reaction. Excellent exo-selectivities are obtained, and the reaction gives products with complete retention of enantiomeric purity when carried out with chiral, nonracemic scaff ...[more]

PMID: 18479131

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