Synthesis of Diruthenium μ-Chloromethylidyne Complex: C-C Bond Formation at the Bridging Carbon Atom via the Reduction of a μ-Chloromethylidyne Ligand

The p-chloromethylidyne complex, [(Cp*RuCl)(2)(mu-CCl)(mu-Cl)] (2) (Cp* = eta(5) -C5Me5), was prepared by the reaction of a triruthenium pentahydrido complex, [{Cp*Ru(mu-H)}(3)(mu(3)-H)(2)] (1), with CCl4. The reaction of 2 with Zn in an ethylene atmosphere resulted in the formation of a mu-ethylidyne-mu-propylidyne complex, [(Cp*Ru)(2)(mu-CMe)(mu-CEt)(mu-ZnCl2)] (3). Formation of a ppropylidyne ligand was unambiguously confirmed by X-ray diffraction, and the mu-propylidyne ligand was probably formed via the migration of an ethyl group derived from ethylene to a transiently generated mu-carbido ligand. A linear mu-carbido complex, [(Cp*Ru)(2) (mu-C){mu-eta(1):eta(2)-ZnCl(-OC(OEt)CH=CHC(OEt)-O-}(2)] (4), was prepared by the reaction of 2 with diethyl maleate in the presence of Zn. Two ZnCl moieties were chelated by diethyl maleate, and the Zn-maleate moieties bridged the Ru=C=Ru skeleton in a head-to-tail fashion.

Automated summary

In this study, a p-chloromethylidyne complex was prepared and reacted with Zn in an ethylene atmosphere to form a mu-ethylidyne-mu-propylidyne complex, involving the migration of an ethyl group to form the mu-propylidyne ligand. Additionally, a linear mu-carbido complex was synthesized, with Zn-maleate moieties bridging the Ru=C=Ru skeleton.