Divergent Carbocyanation and Hydrocyanation of Alkynes Enabled by Photoinduced Nickel-Catalyzed Homolytic Bond Cleavage of C(sp3)–N Bond in Isonitriles

Abstract Catalytic strategies for breaking and forming chemical bonds are longstanding goals in chemical synthesis. However, the activation of inert chemical bonds remains a significant challenge. Recently, our group successfully developed a C(sp3)–N bond homolytic activation strategy for isonitriles by using an in situ-generated electronically active nickel complex. This strategy bypasses the thermodynamically unfavorable two-electron or one-electron oxidative addition process, allowing us to invent an unprecedented ‘cut-and-sew’ reaction using isonitriles and alkynes. This transformation proceeds under simple and mild conditions, demonstrating a broad substrate scope with excellent functional-group compatibility and atom economy. Moreover, we applied this activation mode to develop a selective hydrocyanation of alkynes with isonitriles as cyanating agents in the presence of an exogenous photocatalyst. 1 Introduction 2 Discovery of the Photoactivation Process of Nickel–Isonitrile Complexes 3 Photoinduced Nickel-Catalyzed Cut-and-Sew Reaction of Isonitriles and Arylalkynes 4 Dual Nickel/Photoredox-Catalyzed Hydrocyanation of Alkynes with Isonitriles 5 Proposed Reaction Pathways 6 Conclusion and Perspectives