title: DABCO-promoted synthesis of pyrazoles from tosylhydrazones and nitroalkenes.
abstract: An efficient synthesis of pyrazoles from tosylhydrazones and nitroalkenes was developed. In comparison with the previously reported 1,3-dipolar cycloaddition reaction of diazo compounds with electron-deficient alkenes or alkynes, this methodology proceeded with a sequential Baylis-Hillman/intramolecular cyclization mechanism and a variety of reversed regioselectivity products were prepared in good yields.
authors: School of Pharmacy, Lanzhou University, Lanzhou, P. R. China. tangmeng@lzu.edu.cn
authors: Meng
authors: M
authors: Tang
authors: Wen
authors: W
authors: Zhang
authors: Yuanfang
authors: Y
authors: Kong
mesh_terms: D000475:Alkenes / Q000737:chemistry*; D003500:Cyclization; D006835:Hydrazones / Q000737:chemistry*; D015394:Molecular Structure; D009574:Nitro Compounds / Q000737:chemistry*; D010879:Piperazines / Q000737:chemistry*; D011720:Pyrazoles / Q000138:chemical synthesis*; D013237:Stereoisomerism; D014105:Tosyl Compounds / Q000737:chemistry*
chemical_list: D000475:Alkenes; D006835:Hydrazones; D009574:Nitro Compounds; D010879:Piperazines; D011720:Pyrazoles; D014105:Tosyl Compounds; C007306:triethylenediamine