Enantioselective Addition of Me₂Zn to Aldehydes Catalyzed by ClCr(Salen)

Significance

The authors offer a simple, elegant and very general method for the enantioselective addition of dimethylzinc to aldehydes. Salen ligands are relatively easy to prepare, and loading as low as 1-2 mol% is sufficient. The enantioselectivities are good to excellent for many types of aldehydes and are above 90% for all substituted benzaldehydes tested. The procedure is operationally quite simple, does neither require addition of Ti compounds nor lower temperatures. The catalyst is a commercially available substance.