title: Chiral N-heterocyclic carbenes as stereodirecting ligands in asymmetric catalysis.
abstract: In recent years, N-heterocyclic carbenes (NHC) have proved to be a versatile class of spectator ligands in homogeneous catalysis. Being robust anchoring functions for late transition metals, their ligand donor capacity and their molecular shape is readily modified by variation of the substituents at the N-atoms and the structure of the cyclic backbone. After the first attempts to use chiral NHC ligands in asymmetric catalysis in the late 1990's, which initially met with limited success, several novel structural concepts have emerged during the past two years which have led literally to an explosion of the field. With a significant number of highly selective chiral catalysts based on chiral NHCs having been reported very recently, several general trends in the design of new NHC-containing molecular catalysts for stereoselective transformations in organic synthesis emerge.
authors.affiliation: Laboratoire de Chimie Organométallique et de Catalyse, Université Louis Pasteur, 4, rue Blaise Pascal, 67000 Strasbourg, France. bellemin@chimie.u-strasbg.fr
authors.forename: Vincent
authors.initials: V
authors.lastname: César
authors.forename: Stéphane
authors.initials: S
authors.lastname: Bellemin-Laponnaz
authors.forename: Lutz H
authors.initials: LH
authors.lastname: Gade
mesh_terms: D002384:Catalysis; D006838:Hydrocarbons; D008024:Ligands; D008697:Methane / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry*; D008958:Models, Molecular; D008968:Molecular Conformation; D009930:Organic Chemicals / Q000138:chemical synthesis / Q000737:chemistry; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D006838:Hydrocarbons; D008024:Ligands; D009930:Organic Chemicals; D009942:Organometallic Compounds; C030011:carbene; D008697:Methane