Abstract: Kinetic studies have shown that azidoformates decompose thermally in a variety of solvents in a clean first-order reaction, the rate-determining step being evolution of nitrogen and formation of a nitrene. The nitrene reacts with saturated hydrocarbons by insertion into a CH bond and by abstraction of two hydrogen atoms from adjacent carbons. The insertion reaction is highly selective, the primary: secondary: tertiary reactivity being in the ratio of 1: ...