Mono‐, Bi‐ and Tridentate N‐Heterocyclic Carbene Ligands for the Preparation of Transition‐Metal‐Based Homogeneous Catalysts

This microreview focuses on the preparation of homogeneous catalysts of group 8–11 metals containing N‐heterocyclic carbene ligands. The current status of the design of mono‐, bi‐ and tridentate NHC ligands is reviewed through the description of the authors' own work. The catalytic applications of such complexes include hydrogen‐borrowing, C–C coupling, reduction of double bonds and C–H activation reactions. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)