A Novel Dinuclear Chiral Niobium Complex for Lewis Acid Catalyzed Enantioselective Reactions: Design of a Tridentate Ligand and Elucidation of the Catalyst Structure

Two's company: By using a novel chiral ligand a dinuclear chiral niobium catalyst for highly enantioselective Mannich‐type reactions was developed. Tridentate binol derivatives provide excellent asymmetric environments around the niobium atom, and the Mannich‐type reactions proceeded smoothly in high yields with high enantioselectivities (see scheme; NMI=N‐methylimidazole).