ABSTRACT
It has been well established that in the presence of free-radical initiators [12], H2S and mercaptans add to olefins in an anti-Markovnikov fashion by a mechanism similar to the well-known inverse addition ofhydrogen bromide to olefins. Several free-radical initiators [13] and ultraviolet light (UV) [14] catalyze this reaction. Olefins exposed to air even for short periods contain enough peroxides to initiate this reaction, while radical inhibitors (e.g., hydroquinone) retard it. A general mechanism may be written, involving a secondary free-radical intermediate that undergoes chain transfer to give a primary mercaptan or sulfide from the addition of H2S or mercaptan, respectively, to an alpha olefin.
