Catalytic Asymmetric Addition of Dialkylzinc Reagents to α-Aldiminoesters

The first catalytic, enantioselective addition of organozinc reagents to α-aldiminoesters is described. The use of a Lewis acid/Lewis base containing bifunctional catalyst preorganizes both reactive substrates to promote enantioselective addition over the racemic background reaction and alternative addition modes. Alcohol additives were found to enhance the enantioselection. The addition product was also found to cyclize with remaining substrate to provide imidazolidines.