Benzylic C(sp³)–H/C(sp³)–H Coupling with 2-Azaallyl Anions through Single-Electron Transfer and 1,5-Hydrogen Atom Transfer

Herein is reported a novel transition-metal-free intermolecular C(sp³)-H/C(sp³)-H coupling of <i>N-tert</i>-butyl arylamides with <i>N</i>-benzyl imines through single-electron transfer (SET) and 1,5-hydrogen atom transfer (1,5-HAT) strategies. 2-Azaallyl anions as super-electron-donors (SEDs) undergo SET with <i>N-tert</i>-butyl arylamides to generate 2-azaallyl radicals and amidyl radicals. The amidyl radical undergoes a 1,5-HAT process to form a C-centered radical, which is subsequently coupled to a 2-azaallyl radical to generate new C-C bonds. This method avoids the use of transition metals and photoredox catalysts with good functional group tolerance and yields (29 examples, 87% yield). Radical clock and radical trapping experiments provide significant evidence for the 1,5-HAT process of amidyl radicals.