title: Chemoselective synthesis of substituted pyrazoles through AgOTf-catalyzed cascade propargylic substitution-cyclization-aromatization.
abstract: A cascade AgOTf-catalyzed chemoselective approach to 3,5/1,3-disubstitued pyrazoles from propargylic alcohols and para-tolylsulfonohydrazide has been developed. Good chemoselectivity is observed depending on the different substituents in the alkyne moiety of the propargylic alcohols, generating two different kinds of products through different aromatization mechanisms. The pyrazolo[5,1-a]isoquinoline skeleton can also be effectively constructed by this method through a cascade bicyclization process.
authors.affiliation: Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, Fujian, P. R. China.
authors.forename: Su-Xia
authors.initials: SX
authors.lastname: Xu
authors.forename: Lu
authors.initials: L
authors.lastname: Hao
authors.forename: Tao
authors.initials: T
authors.lastname: Wang
authors.forename: Zong-Cang
authors.initials: ZC
authors.lastname: Ding
authors.forename: Zhuang-Ping
authors.initials: ZP
authors.lastname: Zhan
mesh_terms: D000480:Alkynes / Q000737:chemistry*; D002384:Catalysis; D002625:Chemistry, Organic / Q000379:methods*; D003500:Cyclization; D006834:Hydrazines / Q000737:chemistry; D006841:Hydrocarbons, Aromatic / Q000138:chemical synthesis* / Q000737:chemistry; D008698:Mesylates / Q000737:chemistry*; D020005:Propanols / Q000737:chemistry*; D011720:Pyrazoles / Q000138:chemical synthesis* / Q000737:chemistry; D012997:Solvents / Q000737:chemistry
chemical_list: D000480:Alkynes; D006834:Hydrazines; D006841:Hydrocarbons, Aromatic; D008698:Mesylates; D020005:Propanols; D011720:Pyrazoles; D012997:Solvents; C028255:propargyl alcohol; C012077:trifluoromethanesulfonic acid