Palladium catalysis in organotin chemistry: addition of hexaalkylditins to alkynes

Tetrakis(triphenylphosphine)palladium(0) catalyses the cis-addition of hexaalkylditins R6Sn2 (R = Me, Et, Bu) to acetylene and 1-alkynes; for R = Bu, however, the reaction is not quantitative. With very few exceptions there is no reaction in the case of non-terminal alkynes. The (Z)-distannylalkenes can be partially or completely isomerised to the (E)-alkenes by UV irradiation. The 1,2-distannyl alkenes were characterised by NMR spectroscopy. Experimental details are given for the preparation of ditins R6Sn2 from tin hydrides R3SnH in the presence of tetrakis(triphenylphosphine)palladium(0).