Free-radical-catalyzed isomerization of isocyanides

Abstract

The isomerization of methyl isocyanide and of ethyl isocyanide, catalyzed by methyl radicals produced in the thermal decomposition of di-tert-butyl peroxide, has been studied in the gas phase at temperatures near 100 °C. The Arrhenius parameters for the reaction CH 3 NC + CH 3 → CH 3 + CH 3 CN are E = 7.8 ± 0.3 kcal/mole and A = 10 12.25 mole −1 cc s −1 . It is proposed that the reaction proceeds by addition of the incoming radical to the divalent carbon atom of the isocyanide group, followed by expulsion of the radical originally attached to the N atom. The thermochemistry of addition to the divalent carbon atom is discussed in an Appendix.