Astashko D, Lee HG, Bobrov DN, Cha JK. Stereochemistry of the Kulinkovich cyclopropanation of nitriles.
J Org Chem 2009;
74:5528-32. [PMID:
19527011 PMCID:
PMC2739442 DOI:
10.1021/jo900823h]
[Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The stereochemistry of the Kulinkovich cyclopropanation of nitriles with alkenes has been examined by employing (E)-disubstituted alkenes and deuterium-labeled homoallylic alcohols as a stereochemical probe. An intramolecular cyclopropanation proceeds with preservation of the olefin configuration. On the other hand, intermolecular counterparts occur with both preservation and reversal of the olefin configuration, which corresponds to retention and inversion of configuration at the Ti-C bond, respectively, in the cyclopropane-forming step. These uncommon stereochemical outcomes contrast with that of the Kulinkovich cyclopropanation of tertiary amides.
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