Asymmetric synthesis of O-benzoyl cyanohydrins by reaction of aldehydes with benzoyl cyanide catalysed by BINOLAM-Ti(IV) complexes

The asymmetric cyanobenzoylation of aldehydes has been carried out for the first time, by reaction with benzoyl cyanide in a process catalysed by either (R)- or (S)-3,3'-bis(diethylaminomethyl)-1,1'-binaphthol BINOLAM-Ti(IV) complexes at room temperature and without additives. The reaction can be described as an overall cyano-O-benzoylation of aldehydes where a Lewis acid-Bronsted base (LABB) dual role for the catalyst induced firstly the key enantioselective hydrocyanation, which is then followed by O-benzoylation furnishing enantioenriched O-benzoyl cyanohydrins. (C) 2005 Elsevier Ltd. All rights reserved.