Synthesis of chiral triazolinylidene and imidazolinylidene transition metal complexes and first application in asymmetric catalysis

Deprotonation of chiral triazolium salts and reaction of the resulting nucleophilic carbenes with suitable metal precursors leads to (carbene)transition metal complexes. These contain, depending on the geometry of the complex and the arrangement of the different ligands, a stereogenic center at the metal atom or an axis of chirality with diastereomeric excesses of up to 97%. The application of soluble and immobilized (carbene)transition metal complexes as catalysts in an asymmetric hydrosilylation reaction has been examined. (C) 2001 Elsevier Science B.V. All rights reserved.