Sulfide diaryl alkene

Low-valent nickel species catalyze the reaction between Grignard reagents and aryl or alkenyl sulfide in the preparation of alkylarenes, biaryls, and alkenes (see citations in Ref. ///). Wenkert et al. recently isolated compounds 132 and 133 to show that an oxidative addition occurs between diaryl sulfides and tris(tri-/ -butyl)phosphinonickel (77/). 

In 2006, Ranu reported on an t/ fz-Markovnikov hydro-thiolation of styrene derivatives 205 with disulfides using indium(I) iodide and ZnCl2. Whereas the proposed mechanism invoked the formation of indium(III) thiolate species, the regiochemical outcome of the reaction was opposite to that of In(III)-cataIyzed hydrothiolation of alkenes. It is, thus, reasonable to propose the in situ generation of sulfenyl chloride from ZnCl2 and diaryl sulfides followed by the formation of a thiiranium intermediate 207 that is reductively opened by Ini to give 208. This explanation corresponds to no reaction observed in the absence of either Ini or ZnCL. 

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