Triphenylphosphine‐Mediated Deoxygenative Reduction of CF₃SO₂Na and Its Application for Trifluoromethylthiolation of Aryl Iodides

Abstract

We report herein a practical method for taming Langlois’ reagent CF3SO2Na to generate CuSCF3 by a triphenylphospine‐mediated deoxygenative reduction process. This chemistry highlights a novel utilization of the inherent CF3S skeleton of Langlois’ reagent as a CF3S feedstock under mild conditions. The CuSCF3 intermediate generated by this protocol can react with a wide array of supporting ligands to furnish several air‐stable [LCu(SCF3)] complexes as valuable trifluoromethylthiolating agents. In addition, the CuSCF3 intermediate can be directly employed for the trifluoromethylthiolation of (hetero)aryl iodides with operational simplicity and atomic efficiency.

Trifluoromethanesulfinyl Chloride for Electrophilic Trifluoromethythiolation and Bifunctional Chlorotrifluoromethythiolation

“…Stable and readily available CF 3 SO 2 Na (Langlois reagent) was recently introduced to generate CF 3 S + in situ under reductive and catalytic conditions for electrophilic trifluoromethylthiolation . CF 3 SO 2 Na has also been used to generate CF 3 S − for nucleophilic, trifluoromethylthiolation of aryliodides . More recently, CF 3 SO 2 Cl was introduced for electrophilic trifluoromethylthiolation by using Ph 3 P or (EtO) 2 P(O)H .…”

“…More recently, CF 3 SO 2 Cl was introduced for electrophilic trifluoromethylthiolation by using Ph 3 P or (EtO) 2 P(O)H . Even though some progress has been made, CF 3 SO 2 ‐based trifluoromethylthiolation still has the following limitations: 1) the requirement of stoichiometric amounts of metal salts and 2) a limited scope for electron‐rich heterocycles and alkenes, such as indoles, pyrroles and enamines …”

“…[19] CF 3 SO 2 Na has also been used to generate CF 3 S À for nucleophilic, trifluoromethylthiolation of aryliodides. [20] More recently, CF 3 SO 2 Cl was introduced for electrophilic trifluoromethylthiolation by using Ph 3 Po r( EtO) 2 P(O)H. [21] Even though some progress has been made, CF 3 SO 2 -based trifluoromethylthiolation still has the following limitations:1 )the requirement of stoichiometric amountso fm etal salts and 2) al imited [a] L. Jiang scope for electron-rich heterocycles and alkenes, such as indoles, pyrroles and enamines. [19][20][21] During the trifluoromethylthiolation reactions with CF 3 SO 2 Na or CF 3 SO 2 Cl, reactive speciess uch as CF 3 SSCF 3 andC F 3 SCl were observedf rom the reaction process.…”

“…[20] More recently, CF 3 SO 2 Cl was introduced for electrophilic trifluoromethylthiolation by using Ph 3 Po r( EtO) 2 P(O)H. [21] Even though some progress has been made, CF 3 SO 2 -based trifluoromethylthiolation still has the following limitations:1 )the requirement of stoichiometric amountso fm etal salts and 2) al imited [a] L. Jiang scope for electron-rich heterocycles and alkenes, such as indoles, pyrroles and enamines. [19][20][21] During the trifluoromethylthiolation reactions with CF 3 SO 2 Na or CF 3 SO 2 Cl, reactive speciess uch as CF 3 SSCF 3 andC F 3 SCl were observedf rom the reaction process. [19][20][21] CF 3 SOCl, which could be obtained from commercial suppliers or easily synthesized by the treatment of readily availableC F 3 SO 2 Na and SOCl 2 , [22] has been reported for direct trifluoromethylsulfoxidations.…”

“…[19][20][21] During the trifluoromethylthiolation reactions with CF 3 SO 2 Na or CF 3 SO 2 Cl, reactive speciess uch as CF 3 SSCF 3 andC F 3 SCl were observedf rom the reaction process. [19][20][21] CF 3 SOCl, which could be obtained from commercial suppliers or easily synthesized by the treatment of readily availableC F 3 SO 2 Na and SOCl 2 , [22] has been reported for direct trifluoromethylsulfoxidations. [23] It was reportedt hat CF 3 SOCl could disproportionate into CF 3 SCl and CF 3 SO 2 Cl.…”