Synthesis of α-Difluoromethylene Ethers via Photoredox-Induced Hyperconjugative Ring Opening of gem-Difluorocyclopropanes.

Fluorinated compounds have found widespread applications in pharmaceuticals, agrochemicals, and materials science. Precise construction of α-difluoromethylene ether (CF2-O) moiety in organic molecules is of high demand. Herein, a visible light-promoted reaction protocol for the synthesis of α-difluoromethylene ether from gem-difluorocyclopropane is described. The key ring-opening step is induced by hyperconjugative interaction of cyclopropane with photo-oxidized aromatic rings. This reaction is easy scale-up, and the products bearing a synthetic handle enable their further manipulation.

Copper-catalyzed aerobic decarboxylative sulfonylation of cinnamic acids with sodium sulfinates: stereospecific synthesis of (E)-alkenyl sulfones.

A copper-catalyzed aerobic decarboxylative sulfonylation of alkenyl carboxylic acids with sodium sulfinates is developed. This study offers a new and expedient strategy for stereoselective synthesis of (E)-alkenyl sulfones that are widely present in biologically active natural products and therapeutic agents. Moreover, the transformation is proposed to proceed via a radical process and exhibits a broad substrate scope and good functional group tolerance.