Copper-catalyzed trifluoromethylation of styrene derivatives with CF₃SO₂Na

Abstract

A radical-type copper(i)-catalyzed direct trifluoromethylation of styrene derivatives using CF3SO2Na as a trifluoromethylating source for accessing trifluoromethylated alkenes has been developed.

CF3SO2X (X = Na, Cl) as reagents for trifluoromethylation, trifluoromethylsulfenyl-, -sulfinyl- and -sulfonylation. Part 1: Use of CF3SO2Na

“…Trifluoromethylation of styrene derivatives: An obviously simple route for the synthesis of trifluoromethylated styrene derivatives is the direct C–H trifluoromethylation of alkenes. Very recently, Shen, Loh and co-workers reported a copper-catalysed direct trifluoromethylation of the vinylic C sp2 –H bond of styrene derivatives with CF 3 SO 2 Na, di- tert -butyl peroxide, 10 mol % of copper(I) iodide, 1-methylimidazole (NMI) as ligand to copper and tetrabutylammonium iodide (TBAI) as additive ( Scheme 62 ) [ 87 ]. The mild reaction conditions allowed a wide variety of functional groups to be tolerated and afforded a series of trifluoromethylated styrenes in moderate to good yields and with excellent stereoselectivity.…”

Recent advances in transition-metal-catalyzed incorporation of fluorine-containing groups

“…In 2017, Loh and co-workers [141] introduced a Cu(I/II)-catalyzed C vinyl –H trifluoromethylation of a variety of styrene derivatives. This process was achieved by using 1-methylimidazole (NMI) as ligand and tetrabutylammonium iodide (TBAI) as an additive (Scheme 78).…”

May Trifluoromethylation and Polymerization of Styrene Occur from a Perfluorinated Persistent Radical (PPFR)?

“…[39] Stable at room temperature, PPFR is able to release CCF 3 radicals (Scheme1) [40,41] from 85 8C, and then initiate the radical (co)polymerization of such fluoroalkenes. This ability to release CCF 3 radicals from PPFR was also successfully used in trifluoromethylation of aromaticr ing [42] as well as that of terminal double bond [43] of organic compounds, especially allyl [44] and styrenic [42] ones. For the latter ones, the excess of PPFR led to the formationo ff luoro-trifluoromethylated product containing aC F 3 CH 2 CFHmoiety.H owever,t ot he best of our knowledge, PPFR has never been reportedf or the polymerization of non-fluorinated monomers.…”

“…Surprisingly,p reviouss tudies on the radicala ddition of CCF 3 onto styrene monomers have not reported any trace of trifluromethyl polystyrene. [33,[44][45][46] Hence, the objectives of this article are to demonstrate the possible synthesiso ff luorinated polystyrene initiated by CCF 3 radicals, generated from aperfluororinated hyperbranched persistent radical, being able to both initiatet he radical polymerization of such am onomer and to allow the trifluoromethylation of the aromatic rings.T oe videncet he contribution of the presenceo fthe fluorinea tom on the properties of polystyrene, the resulting fluorinated polystyrenes andt heir thermal properties will be compared to non-fluorinatedo nes initiated with ac onventional peroxydicarbonate initiator.…”

“…This ability to release . CF 3 radicals from PPFR was also successfully used in trifluoromethylation of aromatic ring [42] as well as that of terminal double bond [43] of organic compounds, especially allyl [44] and styrenic [42] ones. For the latter ones, the excess of PPFR led to the formation of fluoro‐trifluoromethylated product containing a CF 3 CH 2 CFH‐ moiety.…”