Fluoroalkylsulfonyl Chlorides Promoted Vicinal Chloro-fluoroalkylthiolation of Alkenes and Alkynes

Abstract

The unprecedented use of CFSOCl for direct bifunctional chloro-trifluoromethylthiolation of alkenes and alkynes is reported. CFSCl, which is generated by the reduction of PPh, undergoes electrophilic addition and then chlorination to give the bifunctionalized products without using an additional chlorine source. The method is also applicable for chloro-difluoromethylthiolation using CFHSOCl.

Trifluoromethanesulfinyl Chloride for Electrophilic Trifluoromethythiolation and Bifunctional Chlorotrifluoromethythiolation

“…It seems that the CF 3 SOCl system was more efficient than our previously reported CF 3 SO 2 Cl/PPh 3 system and higher yields were obtained. Similar to alkenes, 9 a – l were found to be Markovnikov products by 1 H NMR analysis while 9 m and 9 n were anti‐Markovnikov products . In contrast to our previous report, internal alkyenes, for example, 1,2‐diphenylethyne, were also applicable to give the product 9 o in 70 % yield.…”

“…Reaction of two nonstyrene‐type alkenes afforded 8 l and 8 m in >80 % yields. The regiochemistry of the bifunctionalized products was confirmed by 1 H NMR analysis, 8 a – l were Markovnikov products while 8 m was produced in high anti‐Markovnikov selectivity. The regiochemistry was similar to our previous CF 3 SO 2 Cl/PPh 3 /DMF system, which made us believe that the process of bifunctionalization of alkenes is also an electrophilic addition by the decomposition product CF 3 SCl.…”

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.…”

Recent Advances in Difluoromethylthiolation

“…The HCF 2 SO 2 Cl (R10)/Ph 3 P system can be used to achieve not only difluoromethylthiolation, 28,29 but also chloro-difluoromethylthiolation. 30 Zhang, Yi, and co-workers disclosed the chloro-difluoromethylthiolation of alkenes and alkynes with this reagent system (Scheme 12). 30 Interestingly, iodide anion was not necessary in this conversion, and the regioselectivity depends on whether the unsaturated bond is conjugated with an aromatic ring or not.…”