Multicomponent Synthesis of Chiral Bidentate Unsymmetrical Unsaturated N-Heterocyclic Carbenes: Copper-Catalyzed Asymmetric C Bond Formation

Abstract : A multicomponent strategy was applied to the synthesis of chiral bidentate unsaturated hydroxyalkyl- and carboxyalkyl-N-heterocyclic carbene (NHC) precursors. The newly developed low-cost chiral ligands derived from amino alcohols and amino acids were evaluated in copper-catalyzed asymmetric conjugated addition and asymmetric allylic alkylation, which afforded the desired tertiary and quaternary carbon stereocenters with excellent regio- and enantioselectivities (up to 99:1 e.r.).