Silylene- and Germylene-Mediated C−H Activation: Reaction with Alkanes, Ethers, and Amines

The reaction of silylene Si[N2(tBu)2C2H2] and Ph−X (X = I, Br) in alkane and ethereal solvents results in the formation of C−H activation product [C2H2(tBu2)N2]SiRI and an equivalent of benzene or oxidative-addition product [C2H2(tBu2)N2]SiPhI. The ratio of products obtained is dependent upon substrate and concentration. This class of reaction has been extended for Si[N2(tBu)2C2H2] and Ge[CH(SiMe3)2]2 to alkylamines. The primary kinetic isotope effect has been measured for the reaction of Si[N2(tBu)2C2H2] with Et2O and determined to be kH/kD = 5.1 ± 0.1. The reaction of Ge[CH(SiMe3)2]2 and Ph−Br with THF was determined to be second order. A large isotope effect ranging from 1.8 to 1.1 was measured for a variety of deuterated aryl halides, consistent with an initial electron transfer to the aryl halide.