Three-component difluoroalkylation and trifluoromethylthiolation/trifluoromethylselenolation of π-bonds

Abstract

This report describes a new method for three-component difluoroalkylation and trifluoromethylthiolation/trifluoromethylselenolation of π-bonds via air-stable SCF and SeCF reagents as free-radical initiators of ethyl iododifluoroacetate. β-Proton elimination can be overcome effectively in this reaction system, and a broad substrate scope, including alkenes and alkynes, makes this approach practical and attractive.

Atom‐Economical and Stereoselective Difunctionalization of Electron‐Withdrawing Alkynes with N‐Trifluoromethylthiophthalimide

“…b) Very recently, Qing disclosed tandem trifluoromethylthiolation/aryl migration of aryl alkynoates to afford a mixtures trifluoromethylthiolated alkenes; Zhu just reported cyanotrifluoromethylthiolation of unactivated dialkyl‐substituted alkynes via intramolecular cyano migration to deliver E ‐olefinic products (Scheme b) . c) Liang described three‐component difluoroalkylation and trifluoromethylthiolation of terminal alkynes to build high stereoselectivity alkenes (Scheme c); A chloro‐trifluoromethylthiolation of terminal alkynes using CF 3 SO 2 Cl as a difunctionalization reagent giving was reported by Zhang (Scheme d) . The vicinal difunctionalization of alkenes and alkynes is particularly important transformations, and can be used to make highly complex molecular architectures.…”

Promising reagents for difluoroalkylation

“…154b In 2018, the Liang group found that air-stable SCF 3 and SeCF 3 reagents could act as free-radical initiators of ethyl iododifluoroacetate via reduction reaction (Scheme 73). 155 In the presence of air-stable SCF 3 and SeCF 3 reagents, the difluoroalkylation reaction of alkynes with ethyl iododifluoroacetate proceeded smoothly. β-Proton elimination was successfully avoided.…”

[(bpy)CuSCF3]: A Practical and Efficient Reagent for the Construction of C–SCF3 Bonds

“…The authors developed a three-component difluoroalkylation and trifluoromethylthiolation of styrene derivatives, and ICF 2 CO 2 Et with reagent 1 in the presence of CsF in 1,2-dimethoxyethane (DME) at 100°C, which led to the desired products in yields ranging between 41 and 83% (Scheme 21). 62 However, none of the desired product was obtained in the reaction with aliphatic alkene. The authors also reported a three-component reaction employing alkynes that underwent difluoroalkylation and trifluoromethylthiolation reactions with ICF 2 CO 2 Et and reagent 1, to generate products with high stereoselectivity.…”