Synthesis of chiral calixarene-like salen ligand and application in catalytic asymmetric friedel-crafts reaction of aromatic amines with glyoxylate

A new calixarene-like salen ligand is efficiently prepared from 2,6-bishydroxymethyl-4-tert-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.