Bifunctional N-Aminopyridinium Reagents Enable C–H Amination, Olefin Carboamination Cascades

C–H amination reactions provide streamlined access to nitrogen-containing small molecules. Here, we disclose benzylic C–H amination with N-aminopyridiniums, which are bifunctional reagents that provide avenues for further diversification. Reductive activation of the incipient N–N bonds unveils electrophilic N-centered radicals, which can be engaged by nucleophilic partners such as olefins, silyl enol ethers, and electron-rich heterocycles. We highlight the synthetic potential of these sequences in the synthesis of tetrahydroisoquinolines, which are important heterocycles in molecular therapeutics, via anti-Markovnikov olefin carboamination. Unlike many C–H amination reactions that provide access to protected amines, the current method installs an easily diversifiable synthetic handle that serves as a lynchpin for C–H amination, deaminative N–N functionalization sequences.