DABCO-promoted synthesis of pyrazoles from tosylhydrazones and nitroalkenes.
نویسندگان
چکیده
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.
منابع مشابه
Synthesis of 1,3,5-tri-substituted pyrazoles promoted by P2O5.SiO2
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Silica supported phosphorus pentoxide (P2O5·SiO2) is an efficient catalyst for synthesis of 1,3,5-substituted pyrazoles via the condensation of 1,3-diketones and hydrazines. Simplicity of procedure, mild condition, being solvent-free, high yields, and easy workup are some advantages of this protocol.
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ورودعنوان ژورنال:
- Organic & biomolecular chemistry
دوره 11 37 شماره
صفحات -
تاریخ انتشار 2013