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Differential Dihydrofunctionalization of Terminal Alkynes: Synthesis of Benzylic Alkyl Boronates through Reductive Three-Component Coupling.

ABSTRACT: The differential dihydrofunctionalization of terminal alkynes is accomplished through the reductive three-component coupling of terminal alkynes, aryl halides, and pinacolborane. The transformation results in hydrofunctionalization of both ?-bonds of an alkyne in a single reaction promoted by cooperative action of a copper/palladium catalyst system. The differential dihydrofunctionalization reaction has excellent substrate scope and can be accomplished in the presence of esters, nitriles, alkyl halides, epoxides, acetals, alkenes, aryl halides, and silyl ethers. Mechanistic experiments indicate that the reaction proceeds through copper-catalyzed hydroboration followed by a second hydrocupration. The resulting heterobimetallic complex is the key intermediate that participates in the subsequent palladium-catalyzed cross-coupling, which furnishes benzylic alkyl boronate products.

SUBMITTER: Armstrong MK

PROVIDER: S-EPMC7304258 | biostudies-literature | 2019 Apr

REPOSITORIES: biostudies-literature

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Differential Dihydrofunctionalization of Terminal Alkynes: Synthesis of Benzylic Alkyl Boronates through Reductive Three-Component Coupling.

Armstrong Megan K MK Lalic Gojko G

Journal of the American Chemical Society 20190403 15

The differential dihydrofunctionalization of terminal alkynes is accomplished through the reductive three-component coupling of terminal alkynes, aryl halides, and pinacolborane. The transformation results in hydrofunctionalization of both π-bonds of an alkyne in a single reaction promoted by cooperative action of a copper/palladium catalyst system. The differential dihydrofunctionalization reaction has excellent substrate scope and can be accomplished in the presence of esters, nitriles, alkyl ...[more]

PMID: 30942593

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