the reagent is N-trifluoromethylthiosaccharin. saccharin is the cyclic imide of o-sulfobenzoic acid and that imide nitrogen is highly acidic. so saccharin is a good leaving group (cf. the similar compound phthalimide) and so this CF₃S- compound is good for achieving electrophilic trifluoromethylthiolation of a number of substrates (electron-rich aromatics, the alpha position of ketones, etc.)
eh, pretty special purpose, but neat. synthesis is kinda ugly (uses carbon disulfide. ew!)
@Alyx Whenever I see talk of chemicals and chemical synthesis I worry that I'm learning forbidden information, like how to make c4, or what's actually inside twinkies.
@Anarkat oh hahaha! well, I suppose there's that touch of forbidden knowledge to this stuff, even though it's all just off a publicly readable website. _Organic Syntheses_ goes back many decades and it's a great resource
CS₂ is poisonous, volatile, extremely flammable, and unavoidable impurities in it make it reek. thumbs down