CATALYTIC COMPOSITION BASED ON CHIRAL LIGANDS WITH MOLYBDENUM, TUNGSTEN OR CHROMIUM AND METHOD FOR ASYMMETRIC ALKYLATION OF ALLYLIC SUBSTRATES

摘要

Complexes of a selected class of chiral ligands with molybdenum, tungsten or chromium, preferably molybdenum, are effective as catalysts in highly enantioselective and regioselective alkylation of allylic substrates. Such compositions provide a versatile and low-cost alternative to existing catalysts. The chiral ligand comprises: (i) a chiral component having first and second chiral centres each substituted with a group X selected from -O- and -NR-, where R is hydrogen or lower alkyl, and (ii) linked to each said group X, a binding group CyN comprising a heterocyclic group having a ring nitrogen atom and optionally substituted with one or more groups selected from alkyl, alkenyl, aryl, aralkyl, alkoxy, aryloxy, acyl, acyloxy, amide, tertiary amine, nitro and halogen, and optionally fused to one or more additional rings.