A [C-1 + C-2] route to propargylidyne complexes

Abstract

The reactions of [W([triple bond, length as m-dash]CBr)(CO)2(Tp*)] (Tp* = hydrotris(dimethylpyrazolyl)borate) with a range of terminal alkynes (RC[triple bond, length as m-dash]CH), mediated by [Pd(PPh3)4] and CuI, afford new proparylidynes [W([triple bond, length as m-dash]C–C[triple bond, length as m-dash]CR)(CO)2(Tp*)] [R = tBu, C6H4X (X = H, NH2, NO2), ferrocenyl, APh3 (A = C, Si, Ge), B(O2CCH2)2NMe]. Similar treatment of [W([triple bond, length as m-dash]CBr)(CO)2(Tp*)] with Ph2Si(C[triple bond, length as m-dash]CH)2 affords the ditungstaoctatetrayne [W2(μ-C6)(CO)4(Tp*)2] while the bimetallic complex [W2{μ-([triple bond, length as m-dash]CC[triple bond, length as m-dash]C)2SiPh2}(CO)4(Tp*)2], which is obtained from [W([triple bond, length as m-dash]CBr)(CO)2(Tp*)] and Ph2Si(C[triple bond, length as m-dash]CSnPh3)2, reacts with [AuCl(THT)] (THT = tetrahydrothiophene) to provide the tetrametallic complex [W2Au2{μ-([triple bond, length as m-dash]CC[triple bond, length as m-dash]C)2SiPh2}Cl2(CO)4(Tp*)2].