N-Heterocyclic Carbene−Osmium Complexes for Olefin Metathesis Reactions

Abstract

The complexes [(η 6 - p -cymene)OsCl( CHPh)(IPr)]OTf ( 4a; IPr = 1,3-bis(2,6-diisopropylphenyl)imidazolylidene) and [(η 6 - p -cymene)OsCl( CHPh)(IMes)]OTf ( 4b; IMes = 1,3-bis(2,4,6-trimethylphenyl)imida-zolylidene) have been prepared by reaction of the corresponding 16-electron compounds [(η 6 - p -cymene)OsCl(NHC)]OTf (NHC = IPr ( 3a ), IMes ( 3b )) with phenyldiazomethane, and their potential as initiators for olefin CM, RCM, and ROMP reactions has been explored.