Reaction of Nitrogen‐Radicals with Organometallics Under Ni‐Catalysis: N‐Arylations and Amino‐Functionalization Cascades

Abstract

Herein, we report as trategy for the generation of nitrogen-radicals by ground-state single electron transfer with organyl-Ni I species.D epending on the philicity of the Nradical, two types of processes have been developed. In the case of nucleophilic aminyl radicals direct N-arylation with aryl organozinc,o rganoboron, and organosilicon reagents was achieved. In the case of electrophilic amidyl radicals,c ascade processes involving intramolecular cyclization, followed by reaction with both aryl and alkyl organometallics have been developed. The N-cyclization-alkylation cascade introduces an ovel retrosynthetic disconnection for the assembly of substituted lactams and pyrrolidines with its potential demonstrated in the short total synthesis of four venom alkaloids. Scheme 1.

Recent Advance in Single Nickel Photocatalysis for Carbon‐Heteroatom Bond Formation

“…We also note that the developed methods often use the aryl halides or their derivatives as the electrophiles and heteroatom‐containing substrates as the nucleophiles in the single photo‐nickel catalysis. In reverse, the coupling processes using heteroatom‐containing substrates as the electrophiles and the nucleophilic aryl partners has not been developed in single nickel photocatalysis, while the amination of organometallics has emerged under thermal conditions [37] . Furthermore, the emerging approaches mainly focus on C(sp2)‐heteroatom bond formations, but not on the C(sp3)‐heteroatom couplings, which have been intensively studied in copper photocatalysis [11,38,39] .…”