A [C1 + C2] route to propargylidyne complexes

The reactions of [W(?CBr)(CO)(2)(Tp*)] (Tp* = hydrotris(dimethylpyrazolyl)borate) with a range of terminal alkynes (RC?CH), mediated by [Pd(PPh3)(4)] and CuI, afford new proparylidynes [W(?C-C?CR)(CO)(2)(Tp*)] [R = Bu-t, C6H4X (X = H, NH2, NO2), ferrocenyl, APh(3) (A = C, Si, Ge), B(O2CCH2)(2)NMe]. Similar treatment of [W(?CBr)(CO)(2)(Tp*)] with Ph2Si(C?CH)(2) affords the ditungstaoctatetrayne [W-2(-C-6)(CO)(4)(Tp*)(2)] while the bimetallic complex [W-2{-(?CC?C)(2)SiPh2}(CO)(4)(Tp*)(2)], which is obtained from [W(?CBr)(CO)(2)(Tp*)] and Ph2Si(C?CSnPh3)(2), reacts with [AuCl(THT)] (THT = tetrahydrothiophene) to provide the tetrametallic complex [W2Au2{-(?CC?C)(2)SiPh2}Cl-2(CO)(4)(Tp*)(2)].