Electrochemical C(sp³)-H Functionalization in Conjunction with Oxidative C-O Coupling/Annulation Facilitated the Unification of highly Decorated Fused Oxepine Architectures

An electrochemical synthetic avenue has been devised for the fused oxepine scaffolds applying methyl ketones and edaravone derivatives under mild, metal- and external oxidant-free conditions liaising C(sp3)-H functionalization along with oxidative cascade annulation. The protocol utilizes DMSO-water as reaction medium and TBAI as both the supporting electrolyte and iodide source, offering high atom economy coupled with minimal additive support. Mechanistic investigations, exemplified by control experiments and cyclic voltammetry studies, provide beneficial insights into the plausible reaction pathway. The synthetic utility of this methodology is further underscored through gram-scale synthesis and post-synthetic functionalization of compound 3h via conjugation with the biologically active molecule ibuprofen.