1,3-Dipolar cycloaddition of chalcones and arylidene-1,3-dicarbonyls with diazosulfone for the regioselective synthesis of functionalized pyrazoles and pyrazolines
作者:Deepa Nair、Prashant Pavashe、Irishi N.N. Namboothiri
DOI:10.1016/j.tet.2018.04.030
日期:2018.5
mediated conditions (Cs2CO3 or NaOEt in EtOH). In few cases, the initial cycloadducts, the intermediate pyrazoline derivatives, could also be isolated and characterized. The pyrazoline derivatives undergo an alkoxide mediated 1,4-elimination, viz. decarboxylation-detosylation to afford the pyrazole derivatives.
本文报道了一种使用重氮砜作为反应性1,3-偶极子和重氮甲烷当量的合成3-酰基吡唑和吡唑-3-羧酸酯的简便方法。在简单的碱介导条件下(EsOH中的Cs 2 CO 3或NaOEt),在与重氮砜的反应中,查耳酮,芳基丙二酸酯和其他芳基-1,3-二羰基化合物表现出良好的偶极亲和性。在少数情况下,也可以分离和表征起始的环加合物,即中间体吡唑啉衍生物。吡唑啉衍生物经历醇盐介导的1,4-消除,即。脱羧-脱甲苯磺酸化得到吡唑衍生物。