Iodine mediated/Brønsted acid-catalyzed dimerization of vinylarenes: a tandem reaction through Ritter trapping to produce N-(4-iodo-1,3-diarylbutyl) acetamides.

In the presence of p-toluenesulfonic acid and iodine, styrene derivatives undergo head-to-tail dimerization followed by trapping with nitriles to yield the corresponding Ritter-type products.