PHOSPHINAMIDES CATALYSTS CONTAINING A STEREOGENIC PHOSPHORUS ATOM FORTHE ASYMMETRIC REDUCTION OF KETONES BY BORANE

The effect of the configuration of the phosphorus atom in phosphinamid e reduction catalysts has been studied through the preparation and use of a series of catalysts containing stereogenic phosphorus atoms of k nown configuration. The conclusion of this work is that a stereogenic centre at phosphorus can improve the selectivity of reductions using t his catalyst, but is not sufficient in itself to generate the higher l evels of selectivity which have been achieved with related catalysts. The X-ray crystallographic structure of a key compound is also feature d. (C) 1997, Elsevier Science Ltd. All rights reserved.