Work

Cobalt-Catalyzed Selective Unsymmetrical Dioxidation of gem-Difluoroalkenes

Year: 2020

Type: article

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)/O 2 /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.

Source: The Journal of Organic Chemistry

DOI: 10.1021/acs.joc.0c00415

Authors: Douglas L. Orsi, Justin T. Douglas, Jacob P. Sorrentino, Ryan A. Altman

Institutions: Vanderbilt University, University of Kansas, Purdue University West Lafayette

Language: English

Topic: Oxidative Organic Chemistry Reactions

Subfield: Organic Chemistry

Field: Chemistry

Domain: Physical Sciences

Open Access status: green

Funders: University of Kansas, National Institutes of Health, National Institute of General Medical Sciences, National Center for Research Resources

Awards: Avance II 500 High Performance Digital NMR Spectrometer System, AVIII HD 400 NMR spectrometer to replace existing DRX 400, Kansas IDeA Network of Biomedical Research Excellence 5, Fluorination and Fluoroalkylation Strategies for Synthetic and Medicinal Chemistry