Proline-Based P,N Ligands in Palladium-Catalyzed Asymmetric pi-Allyl Additions.
Excellent yields and at least 95 % ee can be achieved for the addition of dimethyl malonate to cycloalkenyl acetates by using a palladium complex of the new phosphanyldihydrooxazole ligand L as a catalyst (see scheme). The ligand L can be synthesized from commercially available trans 4-hydroxy-L-proline in four steps. BOC=tert-butoxycarbonyl.
Gilbertson
SR
Department of Chemistry, Washington University, Saint Louis, MO 63130 (USA).
Xie
D