Photocatalyzed Three-Component Difluoroalkyl-Halogenation of Electron-Deficient Alkenes via a Halogen α-Nucleophilic
Xiaoxiao Liu1, Di Chao1, Qingfeng Liu1
1Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, NMPA Key Laboratory for Research and Evaluation of Innovative Drug, School of Chemistry and Chemical Engineering, Henan Normal University, 46 East of Construction Road, Xinxiang, Henan, 453007, China.
Abstract:
Here, we disclose a halogen α-nucleophilic addition via photocatalytic oxidation of the in-situ generated α-carbonyl radical of amides or esters to corresponding α-carbonyl cation. The α-carbon radical is generated by the β-addition of difluoroalkyl radical, formed by the photocatalytic reduction of BrCF2CO2R, to the α,β-unsaturated amides/esters. This umpolung strategy enables an efficient three-component difluoroalkyl-halogenation of α,β-unsaturated amides or esters with BrCF2CO2R and Cl/F-nucleophiles to produce diverse biologically important CF2-containing α-halo-1,5-dicarboxylic derivatives under mild conditions.
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