Trifluoromethanesulfinyl Chloride for Electrophilic Trifluoromethythiolation and Bifunctional Chlorotrifluoromethythiolation.

Trifluoromethanesulfinyl chloride (CF3 SOCl) has been introduced as a new reagent for C-H trifluoromethylthiolation of indoles, thiophenes, and ketones under catalyst-free conditions and in the absence of reductant. The disproportionation of CF3 SOCl to CF3 SO2 Cl and CF3 SCl provides two pathways for the trifluoromethylthiolation. Direct trifluoromethylthiolation with CF3 SCl or trifluoromethylsulfoxidation with CF3 SOCl is followed by reduction with CF3 SOCl. This reagent can be used to functionalize benzothiophenes, benzofurans, and indenes under the promotion of Ag2 CO3 . It can also be used for trifluoromethylthiolation of thiols and benzeneselenols, and 1,2-bifunctional chlorotrifluoromethylthiolation of indoles, styrenes, and alkyenes. The method can also be extended for difluorometylthiolation reactions using CF2 HSOCl.