Cascade Radical 1,2-N-Shift/C-H Bond Coupling, Halogenation and Selenation Enabled by Cooperative Ni/Diboron Catalysis

Herein, we reported an unprecedented, efficient radical cascade merging 1,2-N-shift with C-H bond coupling, halogenation, and selenation via an inert C(sp3)-N bond cleavage, leading to pharmaceutically important β-amino acid motifs. A π-system-independent 1,2-N-shift mode enabled by cooperative Ni/diboron catalysis has been uncovered for the first time, wherein the diboron compounds were observed to function as both an activator for the C(sp3)-N bond and a reductant precursor for Ni catalytic cycle, shedding new light on radical remote migration of N-functionalities without the aid of π-systems. This synthetic method enabled the formation of a new C(sp3)-C(sp2) bond and a new C-N bond using a bench-stable Ni(dme)Br2/pyridine-imidazoline/B2neo2 systems featuring a broad substrate scope and excellent diastereoselectivity, under mild and safe reaction conditions that avoid oxidants, toxic radical initiators, or elevated temperatures, offering an expedient access to useful β-amino acid scaffolds.