Olefin aminations are important synthetic technologies for the construction of aliphatic C-N bonds. Here we report a catalytic protocol for olefin hydroamidation that proceeds through transient amidyl radical intermediates that are formed via proton-coupled electron transfer (PCET) activation of the strong N-H bonds in N-alkyl amides by an excited-state iridium photocatalyst and a dialkyl phosphate base. This method exhibits a broad substrate scope, high functional group tolerance, and amenability to use in cascade polycyclization reactions. The feasibility of this PCET protocol in enabling the intermolecular anti-Markovnikov hydroamidation reactions of unactivated olefins is also demonstrated.
Keywords: amidyl radicals; hydroamidation; hydrogen atom transfer; photoredox catalysis; proton-coupled electron transfer.