Oxidative Addition of Silicon–Chloride Bonds to a Zerovalent Ruthenium Center and Direct Generation of an Ethylene Insertion Complex

The oxidative addition of a silicon–chloride (Si–Cl) bond to a metal center can be a key reaction step in coordinative silicon chemistry, but this reaction is seldom observed. Herein, we report direct oxidative addition of the Si–Cl bonds of dimethyldichlorosilane (Me2SiCl2) and cyclotrimethylenedichlorosilane [(CH2)3SiCl2] to low-valent ruthenium complexes, yielding the 16e– chloro­(organosilyl)­ruthenium complexes [N3]­Ru­(Cl)­(SiMe2Cl) (4a) and [N3]­Ru­(Cl)­(SiCl­(CH2)3) (4b) ([N3] = 2,6-(MesNCMe)2C5H3N; Mes = 1,3,5-trimethylphenyl; Me = methyl). The reversible reaction of 4a with ethylene yields an 18e– ethylene adduct, in which an ethylene is subsequently inserted into a ruthenium–silicon (Ru–Si) bond to produce the 16e– complex [N3]­Ru­(Cl)­(CH2CH2SiMe2Cl) (7). This study provides a good example of the direct generation of an ethylene insertion product, which is an important intermediate in the catalytic reduction of unsaturated molecules.