(544gt) Electrically Enhanced Catalytic Transfer Hydrogenation of Acetophenone in a Biphasic System
Phase transfer catalysis is an important and growing technique in the overall field of catalysis and green chemistry. While increasing the selectivity and reducing the pollution, it is not efficient due to the mass transfer limitation. Electric field has been proved to improve mass transfer in biphasic systems, and oriented electric field has been shown to lower the reaction barrier and achieve higher selectivity or conversion. However, phase transfer catalysis coupled with external electric field has not been widely investigated. In the present work, the effects of external electric field on catalytic phase transfer hydrogenation of acetophenone was studied. The two phase system was set up with sodium formate solution as aqueous phase and acetophenone as organic phase. RuCl(p-cymene)[(S,S)-Ts-DPEN] was employed as catalyst, which dissolves in organic phase. With the same reaction time of 24 h, the yield of 1-phenylethanol was enhanced by 2.8 times, from 4.7% to 13.1%. The selectivity was enhanced by about 2.5 times at the same time. The enhancement was possibly due to the enriched formate species transferred to the interface / organic phase by the electrostatic force. In order to eliminate the mass transfer limitation and reveal the effects of electric field only on the catalyst orientation and performance, an electrostatic spraying reactor will be employed in further experiments. Modeling simulation will also be done to reveal the possible mechanism of this reaction system.