Treatment of stilbene and acenaphthylene derivatives with Mg turnings in the presence of aliphatic acid anhydrides and trimethylsilyl chloride (TMSCl) in N,N-dimethylformamide (DMF) brought about a facile and efficient cross-coupling to give C-acylation products in moderate to good yields. The reaction may be initiated by electron transfer from magnesium to the carbon-carbon double bonds of the substrates