Transition-metal-free electrochemical oxidative C(sp2)-H trifluoromethylation of aryl aldehyde hydrazones

A simple protocol of metal-free C-H trifluoromethylation of hydrazones via electrolysis was developed. This environment-friendly transformation showed high efficiency, good tolerance, and scaled-up functionalization, providing the desired products in moderate to good yields. At the same time, a high yield can be obtained for the substrates either bearing an electron-donating group or an electron-withdrawing group by using different trifluoromethyl reagents. In addition, the radical mechanism was confirmed by the control experiment.

Automated summary

A simple metal-free protocol for C-H trifluoromethylation of hydrazones via electrolysis was developed. This environmentally friendly transformation exhibited high efficiency, good tolerance, and the ability to scale-up functionalization, yielding the desired products in moderate to good yields. Additionally, different trifluoromethyl reagents were used to achieve high yields for substrates containing either electron-donating or electron-withdrawing groups. The radical mechanism was confirmed through control experiments.