Abstract
The essential role of pyrrole in comprehending the chemistry of living organisms, coal surrogates and novel drugs is indisputable. However, literature reports a few studies on its reactivity toward prominent oxidizing agents. Herein we present a comprehensive mechanistic study of oxidation of unsubstituted pyrrole with singlet oxygen (O2 1∆g) by deploying a quantum chemical framework leading to the production of succinimide, as the major products, through a Diels-Alder addition of O2 1∆g to the aromatic ring. Other products, comprising maleimide, hydroperoxide, formamide or epoxide adducts, appear to form via rather minor channels. Additionally, we determined that, the primary Diels-Alder channel encompasses a barrier of 41 kJ/mol with a fitted rate constant of k(T)=1.87×10-13 exp(-48 000/RT) cm3 molecule-1 s-1