A Mild Radical Method for the Dimerization of Dithiocarbamates

A general, practical, and efficient method for the dimerization of dithiocarbamates has been developed that can be used to prepare the corresponding bis(1-arylimino-1-alkyl/arylthiomethyl) disulfides with dilauroyl peroxide (DLP) as mild oxidant. Notably, a lauroyl radical, rather than an undecyl radical, was established as the radical hydrogen-abstractor during the dimerization process. The amount of DLP impacts the dimerization yield, with 50 mol-% DLP giving the disulfides in the highest yields. The use of an excess of DLP generates the undecyl radical, which decomposes the disulfides rapidly to the corresponding isothiocyanates.