title: One-pot synthesis of pyrazoles through a four-step cascade sequence.
abstract: A one-pot synthesis of 3,4,5- and 1,3,5-pyrazoles from tertiary propargylic alcohols and para-tolylsulfonohydrazide has been accomplished. The pyrazoles are formed through a four-step cascade sequence, including FeCl3 -catalyzed propargylic substitution, aza-Meyer-Schuster rearrangement, base-mediated 6π electrocyclization, and thermal [1,5] sigmatropic shift. In this reaction, the 3,4,5- and 1,3,5-pyrazoles are produced selectively according to different substituents in the starting alcohols.
authors: Department of Chemistry and Key Laboratory for Chemical Biology of Fujian Province, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, Fujian, PR China.
authors: Lu
authors: L
authors: Hao
authors: Jun-Jie
authors: JJ
authors: Hong
authors: Jun
authors: J
authors: Zhu
authors: Zhuang-Ping
authors: ZP
authors: Zhan
mesh_terms: D000438:Alcohols / Q000737:chemistry; D000480:Alkynes / Q000737:chemistry*; D002384:Catalysis; D015394:Molecular Structure; D020005:Propanols / Q000737:chemistry*; D011720:Pyrazoles / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D000438:Alcohols; D000480:Alkynes; D020005:Propanols; D011720:Pyrazoles; C028255:propargyl alcohol