Synthesis and reactivity of an anionic allenylidene complex†
Abstract
The reaction of [W(CC
CSiMe3)(CO)2(Tp*)] (Tp* = hydrotris(dimethylpyrazolyl)borate) with MeLi generates the first example of an anionic allenylidene complex Li[W(
C
C
CMeSiMe3)(CO)2(Tp*)] which reacts with electrophiles (H+, Me+) at the β-carbon to afford vinylcarbyne (allylidyne) complexes [W(
CCE
CMeSiMe3)(CO)2(Tp*)] (E = H, Me), and with bromine provides the unprecedented binuclear bis(carbyne) complex {C(
CMeSiMe3)C
W(CO)2(Tp*)}2via oxidative C–C coupling at the β-carbon.