Synthesis of p-cymene by the electrocatalytic oxidation of α-terpinene and γ-terpinene

Abstract

Producing flavors and green fine chemicals from monocyclic terpenes in plant essential oils is a promising approach. However, the traditional method remains challenging due to harsh reaction conditions and the use of precious metals or metal oxides as catalysts. Here, we report an environmentally friendly electrochemical method for p-cymene synthesis from natural α-terpinene and γ-terpinene by oxygen-free catalytic dehydrogenation. The results showed that the microenvironment of the reaction interface can be modulated by changing the cation concentration and alkalinity to achieve the selective dehydrogenation and aromatization of a specific C–H on the terpinene ring. Further, a preliminary investigation using cyclic voltammetry (CV) and density functional theory (DFT) calculations revealed the mechanism of the base enhancing the reactivity.