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

The ultrasonic effects on the electroreduction of methyl and allyl halides (RX) to the corresponding stannanes (R3SnSnR3 and R4Sn) 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 (CH3)(3)SnSn-(CH3)(3) to (CH3)(4)Sn from CH3I was significantly increased under irradiation. This fact is rationalized as being due to because the intermediate species [(CH3)(3)Sn .] formed by the primary one-electron reduction of CH3I 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 CH3Br and C3H5Br Seemed to be slightly different from those in the reduction of CH3I.