Fluorinating electrophilic interception in the oxidation or protonation of alkynyl tetracoordinate borons

Abstract

Introduction of fluorine atoms or fluorine-containing moieties into organic molecules can dramatically influence their properties, thereby increasing their applicability as drugs or building blocks for organic materials. Herein, we report intriguing fluorinating electrophilic interception achieving the synthesis of various fluorine-containing compounds where oxidation or protodeboronation of alkenyl boron species from 1,2-migration of alkynyl tetracoordinate borons were involved. Obviously, α,α-difluoroketones are readily accessible within 30 min, which might provide an alternative approach to [¹⁸F]α,α-difluoroketones. Meanwhile, versatile monofluoroalkenes, α-SCF₃ ketones, and (highly deuterated) SCF₃-containing alkenes can be assembled in good yields via this strategy. This protocol features tunable synthesis, high stereoselectivity and efficiency, applicability to late-stage modifications of bioactive molecules, and modular introduction of fluorine atoms/fluorinated groups. Additionally, these transformations can perfectly suppress the Zweifel pathway and keep the fluorine atoms/fluorinated groups intact without elimination, and the difluoropiperidine scaffolds could also be forged efficiently via this protocol.