Thio(seleno)cyano-difluoroalkylation of Alkenes Using Visible-Light Photocatalysis

Abstract

A mild and efficient three-component thio(seleno)cyano-difluoroalkylation of simple alkenes is demonstrated using an iridium(ruthenium) photocatalyst. This protocol provides a direct and regioselective installation of both C–S(Se)CN [thio(seleno)cyanation] and C–CF (difluoroalkylation) bonds.

Visible-Light-Induced Copper-Catalyzed Intermolecular Three-Component Difluoroalkyl Thiocyanidation of Alkenes

“…However, the main research object of these methods is trifluoromethylation or perfluoromethylation; thus, there is still great development space for the difluoromethylene thiocyanation reaction. Very recently, during the preparation of this letter, the Hong group developed a simple and practical method for the thio­(seleno)­cyanation–difluoroalkylation of alkenes via visible-light photoredox catalyst iridium (ruthenium) . In a continuation of our previous reports of copper-catalyzed three-component fluoroalkylation reactions, herein, we report visible-light-induced, copper-catalyzed three-component couplings of an array of alkenes and BrCF 2 CO 2 Et with inorganic compound KSCN as the SCN source, which can be achieved under mild conditions (without the assistance of an external oxidant) to afford thiocyanodifluoroalkylation products in moderate to good yields (Scheme d).…”

Organophotocatalyzed Mono- and Bis-Alkyl/Difluoroalkylative Thio/Selenocyanation of Alkenes

“…Recently, Molander et al reported the first photocatalytic 1,2-difunctionalization of N -alkenyl amides with BrCF 2 CO 2 Et and other nucleophiles availed by a radical-polar-crossover pathway (Scheme b) . During the preparation of this paper, Hong et al described thio­(seleno)­cyano-difluoroalkylation of alkenes, which uses an expensive Ir-based photocatalyst and has a limited substrate scope and inadequate synthetic yields . Herein, we report a transition metal-, stoichiometric oxidant-, and additive-free, 1,2-thio/selenocyano-difluoro/alkyl-acetylation of simple styrene and alkene derivatives, using 4CzIPN as the organophotocatalyst.…”

Metal-free phosphine-catalyzed visible-light-induced radical cyclization of alkenes: access to cyclic gem-difluoroacyl scaffolds

“…3 As there is growing recognition of the significance of radical chemistry in difluoroalkylation reactions, the direct generation of difluoroalkyl radical intermediates using ruthenium- or iridium-based photoredox catalysts mediated by visible light has gained great interest. 4…”