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Selective Synthesis of Z-Silyl Enol Ethers via Ni-Catalyzed Remote Functionalization of Ketones.

ABSTRACT: We report a remote functionalization strategy, which allows the Z-selective synthesis of silyl enol ethers of (hetero)aromatic and aliphatic ketones via Ni-catalyzed chain walking from a distant olefin site. The positional selectivity is controlled by the directionality of the chain walk and is independent of thermodynamic preferences of the resulting silyl enol ether. Our mechanistic data indicate that a Ni^(I) dimer is formed under these conditions, which serves as a catalyst resting state and, upon reaction with an alkyl bromide, is converted to [Ni^(II)-H] as an active chain-walking/functionalization catalyst, ultimately generating a stabilized η³-bound Ni^(II) enolate as the key selectivity-controlling intermediate.

SUBMITTER: Guven S

PROVIDER: S-EPMC8193638 | biostudies-literature | 2021 Jun

REPOSITORIES: biostudies-literature

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Selective Synthesis of Z-Silyl Enol Ethers via Ni-Catalyzed Remote Functionalization of Ketones.

Guven Sinem S Kundu Gourab G Weßels Andrea A Ward Jas S JS Rissanen Kari K Schoenebeck Franziska F

Journal of the American Chemical Society 20210525 22

We report a remote functionalization strategy, which allows the Z-selective synthesis of silyl enol ethers of (hetero)aromatic and aliphatic ketones via Ni-catalyzed chain walking from a distant olefin site. The positional selectivity is controlled by the directionality of the chain walk and is independent of thermodynamic preferences of the resulting silyl enol ether. Our mechanistic data indicate that a Ni(I) dimer is formed under these conditions, which serves as a catalyst ...[more]

PMID: 34033717

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