Enantioselective copper-catalyzed SN2' substitution with Grignard reagents

Cinnamyl chlorides undergo selective SN2´ allylic substitution by Grignard reagents using catalytic amount (1 mol%) of CuCN and 1-2 mol% trivalent phosphorus ligands, in dichloromethane. With chiral phosphorus ligands derived from TADDOL ee's up to 73% could be obtained