Dialkylzinc additions with a chiral osmaimidazolidine ligand from asymmetric diamination of olefins

A new chiral ligand was prepared in a convenient two-step procedure starting from an asymmetric diamination reaction. Subsequent treatment of the resulting osmaimidazolidine with a phenyl Grignard reagent and titanium tetra(iso-propoxide) furnished a complex that catalyses asymmetric dialkylzinc additions to aromatic aldehydes. (C) 2003 Elsevier Science Ltd. All rights reserved.