Polyethylene Glycols as Efficient Catalysts for the Oxidation of Bicyclic Monoterpenes by Ceric Ammonium Nitrate in Acetonitrile under Acid-Free Conditions: Kinetic and Mechanistic Approach

摘要

Polyethylene glycols (PEG) acts as efficient catalysts for the oxidation of bicyclic monoterpenes such as borneol, isoborneol, and camphor by ceric ammonium nitrate (CAN), a laboratory desktop reagent, in acetonitrile medium under mineral acid-free conditions. The kinetics of the reactions revealed first-order dependence on in both [CAN] and [bicyclic terpene]. The rate of oxidation is accelerated with an increase in [PEG] linearly, which could be explained by considering PEG-bound oxidant (PEG-CAN) as more reactive species than (CAN) itself. The mechanism of oxidation in PEG media has been explained through the participation of PEG-bound oxidant (PEG-CAN) and bicyclic monoterpene in the slow step. (C) 2018 Wiley Periodicals, Inc.