C(sp3)–N Coupling of Nonactivated Alkyl Boronic Pinacol Esters by the Merger of Amino Radical Transfer and Copper Catalysis

Metal-catalyzed C(sp³)-N coupling remains a formidable synthetic challenge, especially with alkyl electrophiles, due to competing pathways such as slow oxidative addition, β-hydride elimination, and alkyl isomerization. While alkyl halides are commonly used, their limitations have spurred interest in alternative coupling partners. Alkyl boronic pinacol esters (Bpins), though stable and widely accessible, are underutilized in C-N coupling due to their poor transmetalation reactivity and susceptibility to protodeborylation and isomerization. Here, we report a dual catalytic strategy that merges copper catalysis with photocatalytically enabled amino radical transfer (ART) to achieve C(sp³)-N coupling of nonactivated alkyl Bpins under mild, redox-neutral conditions. Readily available morpholino benzoate acts both as an aminyl radical precursor and as an internal oxidant, circumventing the need for external oxidants and enabling efficient coupling between two nucleophiles. This strategy delivers a general and regioselective platform for C(sp³)-N bond formation, accommodating a broad array of amines (12 classes), including indoles, indazoles, pyrazoles, anilines, and sulfonamides. The synthetic utility is further exemplified through the late-stage functionalization of complex drug molecules and a one-pot hydroamination of alkenes.