Stabilization of singlet ethoxycarbonylnitrene by 1,4-dioxan. Part 4. Yield of nitrene products in 1,4-dioxan–cyclohexane and effect of cyclohexane-1,2-dione on C–H insertion

Abstract

A study of the yield of ethoxycarbonylnitrene products for the thermolysis and photolysis of ethyl azidoformate in 1,4-dioxan–cyclohexane shows that the singlet state of the nitrene is stabilized by 1,4-dioxan. The results for the effect of added cyclohexane-1,2-dione both on the yield and on the selectivity for the insertion of nitrene suggest that the dione predominantly traps the triplet rather than the singlet nitrene to give 3-ethoxycarbonylimino-2-hydroxycyclohexanone, and that a complex which can react with the C–H bonds of cyclohexane is formed by inter-action of 1,4-dioxan with the singlet, not the triplet nitrene.