The complexes [Tp Br3 Ag] 2 ‚CH 3 COCH 3 (1) and Tp Br3 Ag(thf) (2) catalyze the insertion of the :CHCO 2 Et group from ethyl diazoacetate (EDA) into the saturated C-H bonds of several C5, C6, and C8 linear and branched alkanes. In addition to secondary and/or tertiary sites, the unprecedented insertion into the primary C-H bonds of the substrates studied has been observed with variable regioselectivity, toward the methyl groups, within the range of 40-60% for branched and nearly 25% for linear alkanes.

DFT Becke3LYP calculations are applied to the computational study of the activation of alkane C−H bonds by metallocarbene homoscorpionate complexes. A total of 16 different combinations of metallocarbene complex and alkane are explored, defined by the use of TpAgC(H)(CO2CH3), TpBr3AgC(H)(CO2CH3), TpCuC(H)(CO2CH3), and TpBr3CuC(H)(CO2CH3) species as metallocarbene and methane, ethane, propane, and butane as alkane. The reaction is found to be under kinetic control, and the selectivity is decided in a step with a low-barrier transition state where the key bond-breaking and bond-forming processes take place in a concerted way. This transition state has several possible conformations, which are systematically explored to find the one with lowest energy for each reaction. Variations of the energy barrier as a function of the nature of metal, ligand, and alkane are analyzed and discussed.

The carbon-hydrogen bonds of alkanes, R-H, can be converted in high yields into amino functionalities (R-NHTs; Ts ) p-toluensulfonyl), with the aid of silver-based catalysts in a reaction implying the thermal (80 °C) insertion of a nitrene NTs unit into the C-H bond of the hydrocarbon. Complexes Tp x Ag (Tp x ) hydrotris(pyrazolyl)borate ligand) serve as catalysts and PhIdNTs serves as the nitrene source.