Dual NHC/HAT-Promoted Esterification to Access α-Aryl Glycines

α-Aryl glycines are among the most important carbonyl compounds, particularly as nonproteinogenic α-amino acids present in many pharmacophores. As such, many strategies have been developed to access this motif, but direct carboxylation methods remain underdeveloped. Herein, we employ a dual NHC/HAT catalysis strategy to access 2-azaallyl radicals, which subsequently couple with in situ-generated ester azolium radical intermediates. Base-mediated collapse of the ensuing tetrahedral intermediate liberates the NHC catalyst and benzophenone-protected aryl glycine. This methodology was employed to esterify a variety of aryl-substituted glycine derivatives, as well as allylic and benzylic sites. Mechanistic studies reveal that this radical process operates under both oxidative and reductive quenching cycles, while preliminary experiments employing a chiral NHC and Lewis acid additive demonstrate modest enantioselectivity.