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Addition of 1,3-dicarbonyl compounds to terminal alkynes catalyzed by a cationic cobalt(iii) complex.

ABSTRACT: The Nakamura reaction using a cationic cobalt(iii) complex, [Cp*Co(CH₃CN)₃][SbF₆]₂ as the catalyst under neutral and aerobic conditions at 110 °C has been described. In solution, the complex is expected to lose a hemilabile acetonitrile ligand to produce a highly electron-deficient cobalt(iii) center, and the Lewis acidic nature of the cobalt center has been exploited for the enolization of the dicarbonyl compounds. The reaction of 1,3-dicarbonyl compounds with alkynes affords the corresponding alkenyl derivative. However, the reaction of phenylacetylene and its derivatives with β-ketoesters affords corresponding terphenyl compounds. Details of the mechanisms of the reactions have been proposed based on in situ LCMS measurements.

SUBMITTER: Chandra Sau M

PROVIDER: S-EPMC9056990 | biostudies-literature | 2020 Sep

REPOSITORIES: biostudies-literature

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Addition of 1,3-dicarbonyl compounds to terminal alkynes catalyzed by a cationic cobalt(iii) complex.

Chandra Sau Mohan M Bhattacharjee Manish M

RSC advances 20200930 59

The Nakamura reaction using a cationic cobalt(iii) complex, [Cp*Co(CH3CN)3][SbF6]2 as the catalyst under neutral and aerobic conditions at 110 °C has been described. In solution, the complex is expected to lose a hemilabile acetonitrile ligand to produce a highly electron-deficient cobalt(iii) center, and the Lewis acidic nature of the cobalt center has been exploited for the enolization of the dicarbonyl compounds. The reaction of 1,3-dicarbonyl compo ...[more]

PMID: 35517105

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