Synthesis of Chiral Calixarene-Like Salen Ligand and Application in Catalytic Asymmetric TFriedel-Crafts

A new calixarene-like salen ligand is efficiently prepared from 2,6-bishydroxymethyl-4tert-butyl phenol as starting material by a five-step synthesis. The enantioselective Friedel-Crafts reactions of aromatic amine with glyoxylate are examined employing a titanium derivative of this new ligand as the chiral catalyst, and ­provide modest to excellent enantioselectivities up to 98% ee