Allenyl to Alkenylcarbyne Tautomerization at the Ru–Si Bond of Ru(<i>κP</i>,<i>P</i>,<i>Si</i>) Pincer Complexes
作者:María J. Bernal、Marta Martín、Eduardo Sola
DOI:10.1021/om501238d
日期:2015.2.23
The reactions of the dimer [Ru(mu-Cl)kappa P,P,Si-Si(Me)(C6H4-2-PiPr(2))(2)}](2) (1) with 2-methyl-3-butyn-2-ol and 3-chloro-3-methyl-1-butyne are reported. The former stops at the reagent coordination step forming the mononuclear eta(2) alkyne complex [Rukappa P,P,Si-Si(Me)(C6H4-2-PiPr(2))(2)}Cleta(2)-HC CC(OH)Me-2}] (2), while the latter sequentially produces the allene derivative [Ru(Cl)(2)kappa P,P-Si(Me)(1,2-eta-CH-C-CMe2)(C6H4-2-PiPr(2))(2)}] (3) and its alkenylcarbyne isomer [Rukappa P,P,Si-Si(Me)(C6H4-2-PiPr(2))(2)}(Cl)(2)( CCH=CMe2)] (4). The structures of complexes 3 and 4 indicate that the allenyl fragment that results from the activation of the propargylic chloride uses the Ru-Si bond of the pincer complex to tautomerize into an alkenylcarbyne ligand.