The ligand properties of 2-vinyl-1,2-azaboratabenzene

Lithium 2-vinyl-1,2-azaboratabenzene 1b has been prepared by a multistep synthesis from 2,2-dibutyl-2,5-dihydro-1-trimethylsilyl-1H-1,2-azastannole 6. The reaction of 1b with one equivalent of [Cp∗RuCl]4 gave the very labile sandwich compound 11. However, the reaction of 1b with 2 equiv. of [Cp∗RuCl]4 afforded the stable diruthenium complex 12. The X-ray structure of 12 shows that the first Cp∗Ru moiety is π-bound to the 1,2-azaboratabenzene ring while the second is bound to Cl and to the nitrogen and the pendant B-vinyl of the 1,2-azaboratabenzene group.