Reactions of Ruthenium-Benzylidene Complexes with Bis(trimethylsilyl)ethene and Trimethylsilylstyrenes: Olefin Metathesis versus #beta#-SiMe_3 Elimination/Reductive Elimination

摘要

The benzylidene complexes [Cl_2(PCy_3)_2Ru=C(C_6H_4R-p)H] [R = H (1a), Cl (1b), OMe (1c)] react with (E)-bis(trimethylsily)ethene (2) to give 3,3-bis(trimethylsilyl)-1-arylprop-1-ene, H[H(SiMe_3)_2C]C=C(C_6H_4R-p)H (3a-c). analogously, reaction of 1a with trimethylsilylstilbene gives H(Ph(C=C(SiMe_3)H (4a). in contrast, reaction of 1a with para-methoxysubstituted trimethylsilylstilbene, H(Me_3Si)C=C(C_6H_4OMe-p)H (4b), affords mixtures of the cross-metathesis product, H(Me_3Si)C=C(Ph)H, and various propene derivatives. labeling experiments have been carried out. the mechanism of these reactions is discussed.