New chiral C2 symmetric N-heterocyclic carbene (NHC) ligands with a binaphthyl backbone have been synthesized. X-ray crystallographic analysis of the new NHC-AuCl complex revealed that the phenyl groups of the binaphthyl backbone sterically regulated the direction of the nitrogen substituents of the imidazolylidene which would induce enantioselectivity in reactions. The new cationic NHC-Au(I) complexes efficiently catalyzed the cyclization of a 1,6-ene-yne and the intermediate of the cyclization was trapped by MeOH to afford the final product in high yields with up to 44% ee.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Organic Chemistry
- Inorganic Chemistry