Late-transition-metal complexes of BINOL-derived salens: Synthesis, structure, and reactivity

Salen metal complexes incorporating two chiral BINOL moieties have been synthesized. From a comparison of the parent salen and the BINOL-salen X-ray crystal structures, the effect of the BINOL portions has been examined. In particular, the effects of intramolecular hydrogen bonding on the salen core structure have been determined. The bis(naphthoxide) complexes arising from deprotonation of the BINOL-salen metal complexes have been found to catalyze the asymmetric addition of benzyl malonate to cyclohexenone in up to 90% ee.