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Cobalt-mediated [3 + 2]-annulation reaction of alkenes with alpha,beta-unsaturated ketones and imines.

ABSTRACT: The utility of cobalt dinitrosyl complexes for the [3 + 2] annulation of alkenes with unsaturated enones and ketimines has been demonstrated. Reaction of a series of cobalt dinitrosyl/alkene adducts with conjugate acceptors in the presence of Sc(OTf)(3)/LHMDS formed two new C-C bonds at the carbons alpha to the nitrosyl groups of the substrate, leading to unusual tri- and tetracycles. Retrocycloaddition of these products in the presence of norbornadiene yielded functionalized tetrasubstituted bicyclic olefins.

SUBMITTER: Schomaker JM

PROVIDER: S-EPMC2736344 | biostudies-literature | 2009 Aug

REPOSITORIES: biostudies-literature

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Cobalt-mediated [3 + 2]-annulation reaction of alkenes with alpha,beta-unsaturated ketones and imines.

Schomaker Jennifer M JM Toste F Dean FD Bergman Robert G RG

Organic letters 20090801 16

The utility of cobalt dinitrosyl complexes for the [3 + 2] annulation of alkenes with unsaturated enones and ketimines has been demonstrated. Reaction of a series of cobalt dinitrosyl/alkene adducts with conjugate acceptors in the presence of Sc(OTf)(3)/LHMDS formed two new C-C bonds at the carbons alpha to the nitrosyl groups of the substrate, leading to unusual tri- and tetracycles. Retrocycloaddition of these products in the presence of norbornadiene yielded functionalized tetrasubstituted bi ...[more]

PMID: 19639989

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