Photocatalyzed Defluorinative Dichloromethylation of α-CF<sub>3</sub> Alkenes Using CHCl<sub>3</sub> as the Radical Source
Mei‐Chun Wu, Yixuan Chen, Mingzhi Li, Jun‐An Xiao, Zhipeng Ye, Jianping Guan, Hao‐Yue Xiang, Kai Chen, Hua Yang
Abstract
A visible-light-induced defluorinative dichloromethylation of α-CF3 alkenes was developed with cheap and readily accessible chloroform simultaneously as a dichloromethylation reagent and reaction medium, leading to the facile preparation of new polyhalogenated scaffolds. Notably, the change from CHCl3 to CDCl3 offers a straightforward pathway for accessing the deuterated analogues with excellent degrees of D incorporation. Mechanistic studies suggested the reaction underwent a radical addition of the dichloromethyl radical with alkenes, followed by sequential single-electron transfer and defluorination. This protocol features mild conditions, easy operation, facile scalability, and high efficiency, allowing convenient access to dichloronated gem-difluoroalkenes.