Aliphatic radicals from ethers via photoinduced electron transfer: selective formation and chemistry

Abstract

Irradiation of aliphatic ethers in the presence of benzene-1,2,4,5-tetracarbonitrile (TCB) has been found to cause electron transfer. The radical rations of methyl tert-butyl ether and of 1,4-dioxane are deprotonated under these conditions, and in the case of methyl neopentyl ether, both C–C and C–H bond cleavage take place. The selectivity of the cleavage is rationalized on the basis of thermochemical considerations. The alkyl radicals thus formed add to the TCB radical anion (thus aromatic substitution results) or are trapped with acrylonitrile, followed by coupling with TCB˙^–(radical–alkene addition, followed by aromatic substitution).