Synthesis of Trifluoromethylated Pyrazolidines, Pyrazolines and Pyrazoles via Divergent Reaction of β-CF<sub>3</sub>-1,3-Enynes with Hydrazines
Lan Wei, Shiteng Ding, Mingqing Liu, Zongxiang Yu, Yuanjing Xiao
Abstract
Three types of trifluoromethylated pyrazolidines, pyrazolines, and pyrazoles can be synthesized via divergent reaction of β-CF3-1, 3-enyne with hydrazines. The reaction with simple hydrazine monohydrate or sulfonyl hydrazines as nucleophiles produces 1,3,4-trisubstituted pyrazolines, whereas the reaction with acetyl hydrazine as nucleophiles affords 1,4,5-trisubstituted pyrazolidines. Using phenylhydrazine or tert-butylhydrazine as a reaction partner, the products are easily oxidized to form 1,4,5-trisubstituted pyrazoles.
Topics & Concepts
ChemistryPhenylhydrazineNucleophileHydrazine (antidepressant)Reaction conditionsSulfonylOrganic chemistryCombinatorial chemistryPyrazoleMedicinal chemistryCatalysisChromatographyAlkylFluorine in Organic ChemistrySulfur-Based Synthesis Techniques