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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 (kH /kD =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. 75?%) than reactions in decalin (ca. 30?%).

SUBMITTER: Wang M

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

REPOSITORIES: biostudies-literature

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

Wang Meng M Zhao Yuntao Y Mei Donghai D Bullock R Morris RM Gutiérrez Oliver Y OY Camaioni Donald M DM Lercher Johannes A JA

Angewandte Chemie (International ed. in English) 20191212 4

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 (kH /kD =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 ...[more]

PMID: 31512341

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