(56h) Electrostatically Enhanced Catalytic Phase Transfer Hydrogenation of Acetophenone Under Low External Electric Field

Phase transfer catalysis (PTC) has been extensively studied as a practical method for organic synthesis, as it not only achieves high reactivity and selectivity but also features operational simplicity, and economic and environmentally benign reaction systems. While having various advantages, PTC processes are not as efficient as homogeneous catalysis due to the mass transfer limitation between the two essentially immiscible liquid phases. Additionally, the novel design of phase transfer catalysts is a significant challenge, which limits the potential of PTC for large-scale applications. Here we show that an oriented external electric field (OEEF) can work as phase transfer agent to accelerate the migration of the desired species into a second liquid phase with the absence of phase transfer catalysts. We demonstrated experimentally that an oriented external electric field (OEEF) can act as promoter or inhibitor for the phase transfer hydrogenation of acetophenone depending on its direction. Organic solvents showed differing influences on the reaction attributed to different electrical conductivities. A non-linear dependence of product yield on OEEF potential was also discovered.While further systematic study should be done to obtain insights of the mechanism, this method opens up an opportunity for easy and economic intensification of a wide range of organic reactions with OEEF.