The first phosphine-catalyzed insertion of tellurium into Sn-Sn and Pb-Pb bonds: A simple and efficient route to R3MTeMR3 (M = Sn, Pb)

In the presence of a catalytic amount of a phosphine, elemental tellurium e fficiently inserts into Sn-Sn and Pb-Pb bonds under mild conditions to give the corresponding tellurides R3MTeMR3 (M = Sn, Pb) in quantitative yield. Mechanistic study shows that first a phosphine telluride R'P-3=Te is formed via the reaction of R'P-3 with tellurium, which subsequently reacts with ( R3M)(2) to produce (R3M)(2)Te and concomitantly regenerates R'P-3 to restar t another cycle of the catalytic insertion.