Synthesis of Chiral N-Heterocyclic Carbene Ligands with Rigid Backbones and Application to the Palladium-Catalyzed Enantioselective Intramolecular α-Arylation of Amides

Chiral N-heterocyclic carbene (NHC) ligands having a 2,2'-bisquinoline-based C-2 symmetric skeleton were developed. The ligands exhibited good enantioselectivity in palladium-catalyzed intramolecular alpha-arylation of amides to give 3,3-disubsituted oxindoles.