Salen-derived catalysts containing secondary basic groups in the addition of diethylzinc to aldehydes

A set of modular bifunctional salen catalysts which contain Lewis acid and Lewis base activating groups is described. These groups can be altered independently to control nucleophilic and electrophilic activation of the reacting substrates. These salen-derived catalysts show enhanced reactivity in the addition of diethylzinc to aldehydes with respect to most other salen, amino alcohol, and diamine derived catalysts and reactivity comparable to that of Ti complexes of bis-sulfonamides and diols. Structure: see text.