Chemo-and stereoselectivity of the reaction of aromatic aldehydes with triphenylphosphine and trichloroacetic acid derivatives

Abstract

Aromatic aldehydes react with triphenylphosphine and ethyl trichloroacetate or trichloroacetonitrile to give the corresponding benzylidene dichlorides or α-chlorocinnamic acid derivatives. The chemo-and regioselectivity of these reactions depend on both the substituent in the aromatic ring and reaction conditions. The product configuration was determined on the basis of the coupling constants 2 J CH and 3 J CH in the 13C NMR spectra.