DABCO-promoted synthesis of pyrazoles from tosylhydrazones and nitroalkenes
作者:Meng Tang、Wen Zhang、Yuanfang Kong
DOI:10.1039/c3ob41435c
日期:——
An efficient synthesis of pyrazoles fromtosylhydrazones 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