title: Ion-paired chiral ligands for asymmetric palladium catalysis.
abstract: Conventional chiral ligands rely on the use of a covalently constructed, single chiral molecule embedded with coordinative functional groups. Here, we report a new strategy for the design of a chiral ligand for asymmetric transition-metal catalysis; our approach is based on the development of an achiral cationic ammonium-phosphine hybrid ligand paired with a chiral binaphtholate anion. This ion-paired chiral ligand imparts a remarkable stereocontrolling ability to its palladium complex, which catalyses a highly enantioselective allylic alkylation of α-nitrocarboxylates. By exploiting the possible combinations of the achiral onium entities with suitable coordinative functionalities and readily available chiral acids, this approach should contribute to the development of a broad range of metal-catalysed, stereoselective chemical transformations.
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering, Nagoya University, Nagoya 464-8603, Japan.
authors.forename: Kohsuke
authors.initials: K
authors.lastname: Ohmatsu
authors.forename: Mitsunori
authors.initials: M
authors.lastname: Ito
authors.forename: Tomoatsu
authors.initials: T
authors.lastname: Kunieda
authors.forename: Takashi
authors.initials: T
authors.lastname: Ooi
mesh_terms: D002384:Catalysis; D007477:Ions; D008024:Ligands; D008958:Models, Molecular; D010165:Palladium / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D007477:Ions; D008024:Ligands; D010165:Palladium