CuI-catalyzed sulfenylation of 1-aryl trifluoromethyl pyrazolones: Direct formation of C-S-C bond using aryl iodides and carbon disulfide

C−H Functionalization Reactions of 1‐Aryl‐5‐pyrazolones

“…As shown in Scheme 27, the reaction between S 8 (31) and iodobenzene 4 a generated diphenyl disulfide (30) Recently, V. D. Prajapati and coworkers carried out the sulfenylation of 1-aryl-3-trifluoromethyl pyrazolones 37 (trifluoromethyl analogue of 1) using carbon disulfide (CS 2, 38) and aryl iodides 4 as the sulfenylation reagent in presence of K 2 CO 3 catalyzed by CuI (Scheme 28). [28] A broad array of diversly fluorinated sulfenyl pyrazoles 39 have been obtained in good yields (up to 80 %) using this method. The authors claimed the formation of CÀ SÀ C bond was achieved first time using carbon disulfide (CS 2, 38) along with aryl iodides 4.…”

Mechanochemical Synthesis of Trifluoromethyl Arenes: Nanocellulose-Supported Deaminative Trifluoromethylation of Aromatic Amines

“…The recent estimates suggest that approximately 20% of prescribed or clinically approved pharmaceuticals contain at least one fluorine atom. Moreover, 30–50% of the top-selling drugs (depending on the sales period) contain at least one fluorine atom. − …”

Visible-light-induced C(sp3)−H thiocyanation of pyrazolin-5-ones: a practical synthesis of 4-thiocyanated 5-hydroxy-1H-pyrazoles

“…In this procedure, pyrazol-5-ones were directly thiocyanated with NH 4 SCN and K 2 S 2 O 8 under mild reaction conditions (Scheme 1b). 8 In 2022, Prajapati et al described a strategy for the introduction of elemental sulfur in the CuI-catalyzed sulfenylation of 1-aryl-3-alkyl-1 H -pyrazol-5(4 H )-ones using carbon disulfide as the sulfur source (Scheme 1c), 9 but the aforementioned reactions still required excess oxidants and high temperatures. Coupling of photocatalytic oxidation with the C(sp 3 )–H thiocyanation reaction is an effective and green way to achieve C(sp 3 )–H participation in thiocyanation reactions as compared to traditional C(sp 3 )–H thiocyanations.…”