Open AccessRedox Activity of Pyridine-Oxazoline Ligands in the Stabilization of Low-Valent Organonickel Radical Complexes
Author(s) -
Clifton L. Wagner,
Gabriel Herrera,
Qiao Lin,
Chunhua T. Hu,
Tianning Diao
Publication year - 2021
Publication title -
journal of the american chemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.115
H-Index - 612
eISSN - 1520-5126
pISSN - 0002-7863
DOI - 10.1021/jacs.1c00440
Subject(s) - chemistry , electrophile , redox , ligand (biochemistry) , bromide , divalent , aryl , pyridine , photochemistry , radical ion , coupling reaction , oxazoline , medicinal chemistry , stereochemistry , alkyl , inorganic chemistry , organic chemistry , catalysis , ion , biochemistry , receptor
Low-valent organonickel radical complexes are common intermediates in cross-coupling reactions and metalloenzyme-mediated processes. The electronic structures of N -ligand supported nickel complexes appear to vary depending on the actor ligands and the coordination number. The reduction products of a series of divalent (pyrox)Ni complexes establish the redox activity of pyrox in stabilizing electron-rich Ni(II)-alkyl and -aryl complexes by adopting a ligand-centered radical configuration. The reduced pyrox imparts an enhanced trans- influence. In contrast, such redox activity was not observed in a (pyrox)Ni(I)-bromide species. The excellent capability of pyrox in stabilizing electron-rich Ni species resonates with its proclivity in promoting the reductive activation of C(sp 3 ) electrophiles in cross-coupling reactions.