Late-stage azolation of benzylic C-H bonds enabled by electrooxidation

The installation of azoles via C-H/N-H cross-coupling is significantly underdeveloped, particularly in benzylic C-H azolation due to the requirement for external chemical oxidants and the challenge in controlling the site- and chemo-selectivity. Herein, a late-stage azolation of benzylic C-H bonds enabled by electrooxidation is described, which proceeds in an undivided cell under mild, catalyst- and chemical-oxidant-free reaction conditions. The strategy empowers the C-H azolation on primary, secondary, and even challenging tertiary benzylic positions selectively. The remarkable synthetic utility of our approach is highlighted by its easy scalability without overoxidation of products and ample scope with valuable functional groups The approach can be directly used to install benzyl and azole motifs on highly functionalized drug molecules.

Automated summary

This study presents a late-stage azolation of benzylic C-H bonds enabled by electrooxidation, allowing for highly selective azolation at benzyl positions with easy scalability, no overoxidation of products, and a wide range of valuable functional groups.