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Radical 1,4‐Aryl Migration Enabled Remote Cross‐Electrophile Coupling of α‐Amino‐β‐Bromo Acid Esters with Aryl Bromides
Author(s) -
Tang Shi,
Xu ZhenHua,
Liu Ting,
Wang ShuoWen,
Yu Jian,
Liu Jian,
Hong Yu,
Chen ShiLu,
He Jin,
Li JinHeng
Publication year - 2021
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.202106273
Subject(s) - electrophile , aryl , chemistry , nucleophile , aryl radical , homolysis , bond cleavage , radical , radical ion , coupling reaction , alkyl , medicinal chemistry , combinatorial chemistry , photochemistry , catalysis , organic chemistry , ion
Abstract We report an unprecedented, efficient nickel‐catalysed radical relay for the remote cross‐electrophile coupling of β‐bromo‐α‐benzylamino acid esters with aryl bromides via 1,4‐aryl migration/arylation cascades. β‐Bromo‐α‐benzylamino acid esters are considered as unique molecular scaffolds allowing for aryl migration reactions, which are conceptually novel variants for the radical Truce–Smiles rearrangement. This reaction enables the formation of two new C(sp 3 )−C(sp 2 ) bonds using a bench‐stable Ni/bipyridine/Zn system featuring a broad substrate scope and excellent diastereoselectivity, which provides an effective platform for the remote aryl group migration and arylation of amino acid esters via redox‐neutral C(sp 3 )−C(sp 2 ) bond cleavage. Mechanistically, this cascade reaction is accomplished by combining two powerful catalytic cycles consisting of a cross‐electrophile coupling and radical 1,4‐aryl migration through the generation of C(sp 3 )‐centred radical intermediates from the homolysis of C(sp 3 )−Br bonds and the switching of the transient alkyl radical into a robust α‐aminoalkyl radical.