Generation and reactivities of ethylmethoxysilylene

Tetraarylethylenes from Diarylmethanones and Hexachlorodisilane: The "Sila-McMurry" Reaction

Hexachlorodisilane reacts with diarylmethanones (aryl=C₆ H₅ , 4-MeC₆ H₄ , 4-tBuC₆ H₄ , 4-ClC₆ H₄ , 4-BrC₆ H₄ ) to furnish the corresponding tetraarylethylenes in good yields. The reductive conversion requires temperatures of about 160 °C and reaction times of 60-72 h. In the initial step, the Lewis-basic carbonyl groups likely generate low-valent [SiCl₂ ] as an analogue of [TiCl₂ ] in the classical McMurry reaction. The coupling sequence further proceeds via benzopinacolones, which have been isolated as key intermediates.