A highly efficient heterogeneous palladium-catalyzed cascade three-component reaction of acid chlorides, terminal alkynes and hydrazines leading to pyrazoles
作者:Qiurong Chen、Fang Yao、Lin Yin、Mingzhong Cai
DOI:10.1016/j.jorganchem.2015.12.037
日期:2016.2
MCM-41-immobilized palladium(II) complex [MCM-41-2N–Pd(OAc)2] and 1.0 mol% of CuI, acid chlorides were coupled with terminal alkynes in Et3N at 50 °C to give α,β-unsaturated ynones, which were converted in situ into pyrazoles by the cycloaddition of hydrazines at room temperature with acetonitrile as cosolvent. The cascade reactions generated a variety of pyrazole derivatives in moderate to good yields, and
在0.5摩尔%的3-(2-氨基乙基氨基)丙基官能化的MCM-41固定的钯(II)配合物[MCM-41-2N-Pd(OAc)2 ]和1.0摩尔%的CuI的存在下,酰氯将其与末端炔烃在50°C的Et 3 N中偶合,得到α,β-不饱和炔酮,通过在室温下以乙腈为助溶剂将肼环加成,将其原位转化为吡唑。级联反应以中等至良好的产率生成了多种吡唑衍生物,并且这种非均相钯催化剂显示出比PdCl 2(PPh 3)2更高的催化活性,并且可以被回收并重复使用至少10次连续试验而活性没有降低。