Electrochemical Difunctionalization of gem-Difluoroalkenes: A Metal-Free Synthesis of α-Difluoro(alkoxyl/azolated) Methylated Ethers

Abstract

A scalable electrochemical difunctionalization of gem-difluoroalkenes to structurally versatile difluoro motifs was achieved. This methodology features reagent-free conditions, good functional group tolerance, and a relatively broad substrate scope. Meanwhile, the electrolysis protocol is easy to handle, and the products show good regio-and chemoselectivity. The reaction mechanism was also preliminarily studied.

Electrochemically Direct Fluorination Functionalization of Styrenes with Different Fluorine Source: Access to Fluoroalkyl Derivatives

“…Second, besides the corrosive NEt 3 -HF as both electrolyte and fluorine source, there has been no progress in the application of greener fluorine sources to run electrochemical fluorination. As electro-organic synthesis has gradually been accepted as an environmentally friendly and impressive tool for novel chemical transformations and because of our ongoing interest in the electrochemical introduction of widely applicable fluorine into organic molecules using easily handled fluorine sources, , we report herein, using NEt 3 -HF and CsF as fluorine sources and sodium sulfinate derivatives as sulfonyl or fluorinated alkyl sources, an electrochemical oxidative fluorofunctionalization of styrenes, affording various β-fluorosulfone/fluoromethyl derivatives.…”

Synthesis of Sterically Hindered Dialkyl Ethers via Palladium-Catalyzed Fluoro-alkoxylation of gem-Difluoroalkenes

“…This system was further applied to the synthesis of ethers through C­(sp 3 )–O cleavage components . Despite these advances, the transition-metal-catalyzed oxidized fluorination of gem -difluoroalkenes using aliphatic alcohols as nucleophilic donors, especially the application of sterically hindered tert -substituted alkyl alcohols, still needs to be explored …”

Electrochemical Fluorination Functionalization of gem-Difluoroalkenes with CsF as a Fluorine Source: Access to Fluoroalkyl Building Blocks

“…Given the general demand for organofluoride and our ongoing interest in the direct anodic oxidative functionalizaiton of unsaturated hydrocarbons, we sought to overcome the challenge of a green and operationally simple protocol for synthesis of various perfluoroalkyl molecules by using readily available gem -difluoroalkenes and CsF as reactants (Figure ). The present approach possesses several distinct features: (i) many difluoroalkenes with various functional groups can undergo chemo- and regioselective difluorination, fluoroalkoxylation, and azofluorination under air at room temperature; (ii) CsF acts as an efficient fluorine source; (iii) this transformation is amenable to 18 F labeling chemistry; (iv) the manipulative simplicity of this protocol and potential application of this new class of perfluoroalkyl building blocks would render electrochemical difunctionalization available to broader chemistry community.…”