Integrating Olefin Carboamination and Hofmann‐Löffler‐Freytag Reaction by Radical Deconstruction of Hydrazonyl N−N Bond

Abstract

As a type of elementary organic compounds containing N‐N single bond, hydrazone involved chemical conversions are extremely extensive, but they are mainly limited to N2‐retention and N2‐removal modes. We report herein an unprecedented protocol for the realization of division utilization of the N2‐moiety of hydrazone by a radical facilitated N‐N bond deconstruction strategy. This new conversion mode enables the successful combination of alkene carboamination and Hofmann‐Löffler‐Freytag reaction by the reaction of N‐homoallyl mesitylenesulfonyl hydrazones with ethyl difluoroiodoacetate under photocatalytic redox neutral conditions. Mechanism studies reveal that the reaction undergoes a radical relay involving addition, crucial remote imino‐N migration and H‐atom transfer. Consequently, a series of structurally significant ε‐N‐sulphonamide‐α,α‐difluoro‐γ‐amino acid esters are efficiently produced via continuous C‐C bond and dual C‐N bonds forging.