N-Heterocyclic carbenes: application of ruthenium-alkylidene complexes in ring-opening metathesis polymerization

Novel ruthenium-alkylidene catalysts bearing N-heterocyclic carbenes were a pplied in ring-opening metathesic polymerization (ROMP) reactions of variou s norbornene derivatives. High tolerance towards polar functional groups as well as high catalytic activity is demonstrated. The combination of N-hete rocyclic carbenes and coordinatively labile ligands (phosphanes or chlorobr idged transition metals) on the ruthenium center proves not only successful regarding catalytic performance but also promising with respect to polymer properties. (C) 1999 Elsevier Science S.A. All rights reserved.