Sulphur-substituted organometallic compounds. Part II. Reaction of vinyltin compounds with arenesulphenyl halides and thiocyanates and some properties and reactions of the (2-arylthio-1-halogenoethyl)-triphenyltin addition products

Vinyltin compounds, [R3Sn(CHCH2)](R = Me and Ph), react with sulphenyl chlorides and thiocyanates, R′SX, in aprotic solvents to give products of addition (Markownikoff) to the vinyl bond and cleavage of the vinyl–tin bond [equation (i)]. Cleavage products are exclusively obtained from the most reactive sulphenyl chloride [R3Sn(CHCH2)]+ R′SX →[R3Sn(CHXCH2SR′)]+ CH2CHSR′+[R3SnX](i) used, p-MeC6H4SCI, while both cleavage and addition occur with the less-electrophilic species, 2-O2N-4-YC6H3SX (Y = H, Me, or NO2; X = Cl or SCN). Sulphenate esters do not react. The adducts, [Ph3Sn-(CHXCH2SR′)], are thermally unstable in polar solvents, such as CHCl3, and give CH2= CHSR′. They react with sulphenyl halides, R″SX′, to give unsymmetric disulphides, R′SSR″, CH2CHX. and [Ph3SnX′]. This type of reaction is in contrast to those with Br2, I2, CF3CO2H, Hg[O2Me]2, and HgCl2 in which initially phenyl–tin bond cleavage occurs to give [Ph2ZSn(CHXCH2SR′)]. The latter species are not stable and generally break down to CH2CHSR′ and [Ph2SnXZ](Z = Cl, Br, I, CF3CO2, or MeCO2).