Activation of Dichloromethane by a Bis-NHC Cp*Ru Complex: Formation of a Pentamethyl(chloromethyl)cyclopentadiene Ligand

Abstract

The dinitrogen complex [{Cp*Ru(L)}(2)(mu-N-2)]-[BPh4](2) (L = bis(3-methylimidazol-2-ylidene) reacts with dichloro-methane at room temperature, furnishing the diene derivative [Ru(eta(4), kappa(1)-Cl-C5Me5CH2Cl)Cl(L)][BPh4] as result of CH2Cl2 oxidative addition and subsequent migration of the chloromethyl group into the Cp* ring. Mechanistic insight provided by DFT computations indicate that while the cleavage of the C-Cl bond is not thermodynamically favored, the subsequent migration step is largely exergonic and thus provides the driving force for the formation of the observed product.