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The Critical Role of Reductive Steps in the Nickel‐Catalyzed Hydrogenolysis and Hydrolysis of Aryl Ether C−O Bonds
Author(s) -
Wang Meng,
Zhao Yuntao,
Mei Donghai,
Bullock R. Morris,
Gutiérrez Oliver Y.,
Camaioni Donald M.,
Lercher Johannes A.
Publication year - 2020
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201909551
Subject(s) - hydrogenolysis , decalin , chemistry , ether , aryl , bond cleavage , medicinal chemistry , catalysis , diphenyl ether , kinetic isotope effect , photochemistry , ring (chemistry) , organic chemistry , deuterium , alkyl , physics , quantum mechanics
The hydrogenolysis of the aromatic C−O bond in aryl ethers catalyzed by Ni was studied in decalin and water. Observations of a significant kinetic isotope effect ( k H / k D =5.7) for the reactions of diphenyl ether under H 2 and D 2 atmosphere and a positive dependence of the rate on H 2 chemical potential in decalin indicate that addition of H to the aromatic ring is involved in the rate‐limiting step. All kinetic evidence points to the fact that H addition occurs concerted with C−O bond scission. DFT calculations also suggest a route consistent with these observations involving hydrogen atom addition to the ipso position of the phenyl ring concerted with C−O scission. Hydrogenolysis initiated by H addition in water is more selective (ca. 75 %) than reactions in decalin (ca. 30 %).