The titanium tetrachloride induced synthesis of N-phosphinoylimines and N-sulphonylimines directly from aromatic aldehydes

Abstract

The reaction of phosphinic amides or sulphonamides with an aromatic aldehyde in the presence of titanium tetrachloride and triethylamine provides a simple, one-step preparation of N-phosphinoylimines ( 5a-e) and N-sulphonylimines ( 7a-g). The extension of this reaction to ketones failed to give the desired imines, the aldol condensation products were obtained instead. The reaction of (+)-camphor with phosphinic amides or sulphonamides in refluxing toluene in the presence of titanium tetrachloride and triethylamine affords the (−)-camphorphosphinoyl- and (−)-camphorsulphonylimines in moderate yield.