The Critical Role of Reductive Steps in the Nickel-Catalyzed Hydrogenolysis and Hydrolysis of Aryl Ether C-O Bonds.

ABSTRACT: 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 H₂ and D₂ atmosphere and a positive dependence of the rate on H₂ 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. 7

SUBMITTER: Wang M 

PROVIDER: S-EPMC7003888 | biostudies-literature | 2020 Jan

REPOSITORIES: biostudies-literature