Alternative Mechanisms of the Alkyne to Vinylidene Isomerization Promoted by Half-Sandwich Ruthenium Complexes. X-ray Crystal Structures of [Cp~*Ru=C=CHCOOMe(dippe)][BPh_4] and [Cp~*RuH(C≡ CCOOMe)(dippe)][BPh_4] (dippe = 1,2-bis(diisopropylphosphino)

摘要

The complex [Cp~*RuCl(dippe)]reacts with 1-alkynes in MeOH in the presence of NaBPh_4, yielding the metastable hydrio-alkynyl derivatives [Cp~*Ru(H)(C≡CR)(dippe)][BPh_4](R=COOMe, Ph or SiMe_3), intermediates in the formation of the corresponding vinylidene complexes, to which these compounds rearrange both in solution and in the solid state.