The significance of degenerate processes to enantioselective olefin metathesis reactions promoted by stereogenic-at-Mo complexes.

Journal Article

The present study provides spectroscopic and experimental evidence demonstrating that degenerate metathesis is critical to the effectiveness of this emerging class of chiral catalysts. Isolation and X-ray characterization of both diastereomeric complexes, as well as an examination of the reactivity and enantioselectivity patterns exhibited by such initiating neophylidenes in promoting ring-closing metathesis processes, are disclosed. Only when sufficient amounts of ethylene are generated and inversion at Mo through degenerate processes occurs at a sufficiently rapid rate is high enantioselectivity achieved, irrespective of the stereochemical identity of the initiating alkylidene (Curtin-Hammett kinetics). With diastereomeric metal complexes that undergo rapid interconversion, stereomutation at the metal center becomes inconsequential, and stereoselective synthesis of a chiral catalyst is not required.

Full Text

Duke Authors

Cited Authors

  • Meek, SJ; Malcolmson, SJ; Li, B; Schrock, RR; Hoveyda, AH

Published Date

  • November 18, 2009

Published In

Volume / Issue

  • 131 / 45

Start / End Page

  • 16407 - 16409

PubMed ID

  • 19842640

Electronic International Standard Serial Number (EISSN)

  • 1520-5126

Digital Object Identifier (DOI)

  • 10.1021/ja907805f

Language

  • eng

Conference Location

  • United States