Solvent-free and montmorillonite K10-catalyzed domino reactions for the synthesis of pyrazoles with alkynylester as a dual synthon
作者:Sesuraj Babiola Annes、Rajendhiran Saritha、Saravanan Subramanian、Bhaskaran Shankar、Subburethinam Ramesh
DOI:10.1039/d0gc00162g
日期:——
4-trisubstituted and 1,4-disubstituted pyrazole derivatives. The reaction proceeded via nucleophilic attack of enamine from an intermediate on the β-carbon of an amino acrylate. Experimental outcomes clearly revealed that organic solvents had an adverse effect upon pyrazole formation, and that an oxidative condition in the presence of the reusable clay favored formation of the 1,3,4-trisubstituted pyrazole. The clay
具有高度区域选择性,无溶剂和蒙脱土K10粘土催化的多米诺骨牌工艺与空前的闭环C-C键形成反应被描述用于合成新的1,3,4-三取代和1,4-类二取代吡唑衍生物。该反应通过烯胺的中间体的亲核攻击从氨基丙烯酸酯的β-碳上进行。实验结果清楚地表明,有机溶剂对吡唑的形成有不利影响,并且在可重复使用的粘土存在下的氧化条件有利于1,3,4-三取代的吡唑的形成。在N-溴琥珀酰亚胺催化剂存在下,粘土在高温下热解后得到1,4-二取代的吡唑。