Friedel-Crafts alkylation of benzene with α,β-unsaturated amides

A variety of alpha, beta-unsaturated amides (RHC=CH2CONR'(2), R = H, Me, Ar; R'= H or Et) readily condense with benzene at room temperature in the presence of an excess of aluminum chloride to give the corresponding 3-phenylpropionamides in excellent yields. This simple, one-pot procedure proved to be efficient and very clean. The mechanism of these and related reactions is discussed and the participation of superelectrophilic dicationic intermediates is suggested. (C) 2004 Elsevier Ltd. All rights reserved.