Electrocatalytic C(sp3)-H bond functionalization using biomass-derived electrodes.

Organic electrosynthesis is a versatile and evergreen tool for constructing chemical compounds. However, the study of highly active electrodes has not received enough attention, which limits the further development of organic electrosynthesis. This work introduces a bottom-up route to prepare chitin-derived composite carbon aerogel electrodes (CCAEs), which can be directly used as electrodes in organic electrosynthesis systems. Various metal nanoparticles, such as Pt, Pd, RuO2, Cu and Ni, are well confined in these free-standing and porous CCAEs (M-CCAEs). The linear sweep voltammetry and in-situ Raman tests under electrochemical conditions show that RuO2-CCAEs possess good electrochemical oxidation ability for chlorine anions and good stabilizing effect on the generated chlorine radicals, which can serve as a mediator for the electrochemical C(sp3)-H activation. The combination of M-CCAEs with mediators achieves a series of electrochemical oxidative C(sp3)-H chlorination, bromination, nitration and etherification. Moreover, M-CCAEs promote the electrochemical hydrogen isotope exchange reaction of some important drug molecule structures, such as Ibuprofen, Diclofenac and Zolpidem.