학술논문

Reaction of Nitrogen‐Radicals with Organometallics Under Ni‐Catalysis: N‐Arylations and Amino‐Functionalization Cascades.
Document Type
Article
Source
Angewandte Chemie International Edition. Apr2019, Vol. 58 Issue 15, p5003-5007. 5p.
Subject
*LACTAMS
*CHARGE exchange
*INTRAMOLECULAR catalysis
*ALKALOIDS
Language
ISSN
1433-7851
Abstract
Herein, we report a strategy for the generation of nitrogen‐radicals by ground‐state single electron transfer with organyl–NiI species. Depending on the philicity of the N‐radical, two types of processes have been developed. In the case of nucleophilic aminyl radicals direct N‐arylation with aryl organozinc, organoboron, and organosilicon reagents was achieved. In the case of electrophilic amidyl radicals, cascade processes involving intramolecular cyclization, followed by reaction with both aryl and alkyl organometallics have been developed. The N‐cyclization–alkylation cascade introduces a novel retrosynthetic disconnection for the assembly of substituted lactams and pyrrolidines with its potential demonstrated in the short total synthesis of four venom alkaloids. Nitrogen‐radicals can be generated by ground‐state SET with organo‐Ni complexes to achieve direct amination of aryl organometallics as well as amino‐arylation and, for the first time, amino‐alkylation radical cascades. [ABSTRACT FROM AUTHOR]