Ultrasonic Effects on Electroorganic Processes. Part 9. Current Efficiency and Product Selectivity in the Electroreduction of Alkyl Halides to Alkyl Stannanes at a Reactive Tin Cathode

摘要

The ultrasonic effects on the electroreduction of methyl and allyl halides (RX) to the corresponding stannanes (R_3SnSnR_3 and R_4Sn) at a reactive (consumable) tin cathode were examined. The current efficiency and product selectivity for the reduction were found to be greatly affected by ultrasonic irradiation. For instance, the selectivity for (CH_3)_3SnSn(CH_3)_3 to (CH_3)_4Sn from CH-3I was significantly increased under irradiation. This fact is rationalized as being due to because the intermediate species [(CH_3)_3Sn·] formed by the primary one-electron reduction of CH_3I are activated for their coupling by mobilization on/from the cathode surface under irradiation. On the other hand, the ultrasonic effects on the reduction of CH_3Br and C_3H_5Br seemed to be slightly different from those in the reduction of CH_3I.