Copper-catalyzed C(sp3)−H amination and etherification of unactivated hydrocarbons via photoelectrochemical pathway

Abstract

C(sp³)−H activation and functionalization of unactivated hydrocarbons has provided enormous opportunities for the construction of diverse organic molecules, which facilitates the structural modification of pharmaceutical molecules. To achieve this goal, the direct hydrogen atom transfer (HAT) via radical pathway has become an attractive strategy. Taking the advantage of photo/electrochemistry, we herein describe oxidative C(sp³)−H amination and etherification reactions via a photoelectrochemical pathway, which could directly transform easily available hydrocarbons into N-heterocycle and ether products under mild conditions. Applying 9-phenylacridine as a direct hydrogen atom transfer (d-HAT) reagent under 390 nm LED light irradiation and electrolysis, the scope of our method includes not only simple alkanes, but also a wide range of C(sp³)−H molecules including ethers, thioethers, silanes, and amides. The reaction shows broad scope (>135 examples) and unconventional regioselectivity, with the occurrence of both C(sp³)−H amination and etherification preferentially at the sterically unhindered positions. Furthermore, gram-scale experiments and relevant mechanistic investigations are carried out to illustrate the reaction mechanism.