Photoinduced Regioselective Fluorination and Vinylation of Remote C(sp3)-H Bonds Using Thianthrenium Salts

Org Lett. 2024 May 24;26(20):4388-4393. doi: 10.1021/acs.orglett.4c01420. Epub 2024 May 16.

Abstract

Herein, a photoredox-driven practical protocol for fluorinated alkene synthesis using easily accessible and modular thianthrenium salts with electron-withdrawing alkynes or propargyl alcohols is reported. Vinyl radical intermediates, formed by the reaction between the alkyl or trifluoromethyl thianthrenium salts and electronically diverse alkynes, can mediate the key 1,5-HAT process of regioselective C(sp3)-H fluorination and vinylation. This protocol provides straightforward access to structurally diverse trifluoromethyl- or distally fluoro-functionalized alkene products in 21-79% yields with a broad substrate range under mild photocatalytic conditions.