Si–C bond cleavage by hydride complexes of rhodium and iridium: comparison of Si–C(sp2) and Si–C(sp3) activation

Abstract

Single Si–C_R (R = Ph, Me, Et) bond activation in {o-(Ph₂P)C₆H₄}₂Si(Me)(R) induced by Rh(H)(CO)(PPh₃)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.