Synthesis of substituted isoquinolines via iminoalkyne cyclization using Ag(<scp>i</scp>) exchanged K10-montmorillonite clay as a reusable catalyst
作者:Mariappan Jeganathan、Kasi Pitchumani
DOI:10.1039/c4ra05026f
日期:——
Monosubstituted isoquinolines are synthesized in good to excellent yields by the Ag(I)-exchanged K10-montmorillonite clay catalyzed ring closure of iminoalkynes. This silver catalyzed ring closure is highly effective in cyclizing aryl- and alkyl-substituted iminoalkynes at 100 °C and accommodates a variety of iminoalkynes, thus affording a convenient route to the synthesis of isoquinolines. The other salient features of this procedure are its reusability, environmentally benign nature, high yield, operational simplicity with fewer steps, easy separation, and minimization of metallic wastes. The reaction proceeds smoothly in moderate yields and tolerates various functional groups. The solid catalyst can be readily recovered and reused. Notably, no additional base or other co-catalysts are needed. A plausible mechanism is proposed in which isoquinolines are formed via simultaneous bifunctional acid-base catalysis by Ag(I) clay.
单取代异喹啉通过银(I)交换的K10膨润土催化的亚氨炔环化反应以良好到优异的产率合成。该银催化的环化反应在100°C下对芳基和烷基取代的亚氨炔有很高的高效性,并适应各种亚氨炔,从而提供了一条便捷的合成异喹啉的路线。该程序的其他显著特点包括可重复使用、环保、高产率、操作简单且步骤较少,易于分离,并减少金属废物。反应顺利进行,产率中等,并且耐受多种官能团。固体催化剂可以方便地回收和重复使用。值得注意的是,无需额外的碱或其他助催化剂。提出了一种合理的机制,通过银(I)粘土的双功能酸-碱催化同时生成异喹啉。