Palladium (II/IV) catalyzed cyclopropanation reactions: scope and mechanism.
This report describes detailed studies of the scope and mechanism of a new Pd-catalyzed oxidation reaction for the stereospecific conversion of enynes into cyclopropyl ketones. Unlike related Pd(II/0), Au, and Pt-catalyzed cyclopropane-forming reactions, these transformations proceed with net inversion of geometry with respect to the starting alkene. This result, along with other mechanistic data, is consistent with a Pd(II/IV) mechanism in which the key cyclopropane-forming step involves nucleophilic attack of a tethered olefin onto the Pd(IV)-C bond.
Lyons
Thomas W
TW
University of Michigan, Department of Chemistry, 930 N. University Ave., Ann Arbor, MI 48109, USA.
Sanford
Melanie S
MS