N-heterocyclic carbene-osmium complexes for olefin metathesis reactions

摘要

The complexes [(η6-p-cymene)OsCl(-CHPh)-(IPr)]OTf (4a; IPr = 1,3-bis(2,6-diisopropylphenyl)-imidazolylidene) and [(η6-p- cymene)OsCl(=CHPh)(IMes)]-OTf (4b; IMes = 1,3-bis(2,4,6-trimethylphenyl) imidazolylidene) have been prepared by reaction of the corresponding 16-electron compounds [η6-p-cymene)OsCl(NHC)JOTf (NHC = IPr (3a), IMes (3b)) with phenyldiazomethane, and their potential as initiators for olefin CM, RCM, and ROMP reactions has been explored. © 2005 American Chemical Society.