Intramolecular hydride transfer onto arynes: redox-neutral and transition metal-free C(sp³)–H functionalization of amines

Abstract

Transition metal-free intramolecular hydride transfer onto arynes is reported for the first time. This unique transformation is utilized in redox-neutral intermolecular α-functionalization reactions of different tertiary amines, generating C(sp³)-C(sp³/sp²/sp) bonds in a single synthetic operation. Deuterium labeling studies support initial cleavage of the α-C-H bond <i>via</i> intramolecular 1,5-hydride transfer onto the aryne, which leads to activation of a range of integrated pronucleophiles and ultimately affords a new approach to cross-dehydrogenative coupling reactions which utilize aryne intermediates.