Photocatalytic dehydrations for the Ritter reaction†

The Ritter reaction is a powerful method for the synthesis of amides; however, the photoinduced Ritter reaction of alcohols is rarely reported. We herein report a simple and additive-free photocatalytic dehydration method for the efficient direct conversion of benzyl alcohols to the corresponding amides using an organic photocatalyst 2,4,6-triphenylpyrylium salt. Experimental and computational mechanistic analyses show that a non-conventional generation process of a carbocation is involved in this photoinduced Ritter reaction.