Photocatalytic anti-Markovnikov hydroalkylation of 2-aryl enamides via 1,2-hydrogen atom transfer of amidyl radicals

Abstract

A novel, efficient, and selective photoredox catalytic anti-Markovnikov hydroalkylation of 2-aryl enamides is described. In the presence of base, 2-methyl-2-(N-methylbenzamidooxy)propanoic acid generated an N-centered amidyl radical under visible-light irradiation, which transformed into a C-centered α-amino alkyl radical via an unusual 1,2-hydrogen atom transfer (HAT) process. The addition of an α-amino alkyl radical to 2-aryl enamide and the subsequent reduction-protonation processes afforded 1,3-propanediamine derivatives.