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Cobalt-Catalyzed Selective Unsymmetrical Dioxidation of gem-Difluoroalkenes.

ABSTRACT: gem-Difluoroalkenes represent valuable synthetic handles for organofluorine chemistry; however, most reactions of this substructure proceed through reactive intermediates prone to eliminate a fluorine atom and generate monofluorinated products. Taking advantage of the distinct reactivity of gem-difluoroalkenes, we present a cobalt-catalyzed regioselective unsymmetrical dioxygenation of gem-difluoroalkenes using phenols and molecular oxygen, which retains both fluorine atoms and provides β-phenoxy-β,β-difluorobenzyl alcohols. Mechanistic studies suggest that the reaction operates through a radical chain process initiated by Co(II)/O₂/phenol and quenched by the Co-based catalyst. This mechanism enables the retention of both fluorine atoms, which contrasts most transition-metal-catalyzed reactions of gem-difluoroalkenes that typically involve defluorination.

SUBMITTER: Orsi DL

PROVIDER: S-EPMC7442739 | biostudies-literature | 2020 Aug

REPOSITORIES: biostudies-literature

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Cobalt-Catalyzed Selective Unsymmetrical Dioxidation of gem-Difluoroalkenes.

Orsi Douglas L DL Douglas Justin T JT Sorrentino Jacob P JP Altman Ryan A RA

The Journal of organic chemistry 20200805 16

gem-Difluoroalkenes represent valuable synthetic handles for organofluorine chemistry; however, most reactions of this substructure proceed through reactive intermediates prone to eliminate a fluorine atom and generate monofluorinated products. Taking advantage of the distinct reactivity of gem-difluoroalkenes, we present a cobalt-catalyzed regioselective unsymmetrical dioxygenation of gem-difluoroalkenes using phenols and molecular oxygen, which retains both fluorine atoms ...[more]

PMID: 32697905

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