A bimetallic aluminium(salen) complex for asymmetric cyanohydrin synthesis

In the presence of a phosphine oxide cocatalyst, a bimetallic aluminium(salen) complex was found to catalyse the asymmetric addition of trimethylsilyl cyanide to aldehydes. Under optimised conditions, enantioselectivities of 53-96% were obtained using 2 mol% of the catalyst. An analysis of the reaction kinetics showed that the reactions exhibited first-order kinetics, with the race of reaction being independent of the aldehyde concentration. (C) 2009 Elsevier Ltd. All rights reserved.