Si-C bond cleavage by hydride complexes of rhodium and iridium: Comparison of Si-C(sp~2) and Si-C(sp~3) activation

摘要

Single Si-C_R (R = Ph, Me, Et) bond activation in {o-(Ph _2P)C_6H_4}_2Si(Me)(R) induced by Rh(H)(CO)(PPh_3)_3 was developed. The efficiency of Si-C_R bond breaking reactions increased at 60 °C in the order Si-C_(Et) < Si-C_(Me) < Si-C_(Ph) and strongly depended on the reaction temperature. Elevating the reaction temperature promoted Si-C_(Me) over Si-C_(Ph) bond activation, demonstrating that Si-C_(Me) cleavage is entropically favored but enthalpically unfavored in comparison with Si-C_(Ph) bond cleavage.