Singlet‐oxygen oxidation of thiophenes

Abstract

Abstract Singlet‐oxygen oxidation of alkyl‐ and aryl‐substituted thiophenes has been studied with respect to product formation and relative rates of reaction. The reactivity of thiophenes towards singlet oxygen decreases with the introduction of electron‐withdrawing groups. A comparison of the nature of the products and the relative reactivities towards singlet oxygen of a number of thiophenes with their previously reported anti‐oxidant behaviour indicates that singlet oxygen plays hardly any significant role, if at all, in the desulfurization of thiophenes under autoxidative conditions.