Function of an N-heterocyclic carbene ligand based on concept of chiral mimetic

Abstract

Function of a new N-heterocyclic carbene ligand based on the concept of a chiral mimetic is described. With (4R,5R)-4,5-diphenyl-1,3-dialkyl-4,5-dihydro- 3H-imidazol-1-ium tetrafluoroborates as N-heterocyclic carbene precursors, Rh-catalyzed enantioselective arylation (up to 27% ee) of aromatic aldehydes with arylboronic acids and Pd-catalyzed enantioselective intramolecular α-arylation (up to 66% ee) of N-(2-bromoaryl)-N-alkyl-2-arylpropanamides are investigated. © 2006 Pharmaceutical Society of Japan.