Contrary to the common idea that Fischer indole cyclization often cannot be effectively applied to the synthesis of the corresponding azaindoles, we show that this approach can be actually very efficient for the formation of 4- and 6-azaindoles bearing an electron-donating group on the starting pyridylhydrazines. Two 4-azaindole natural product analogues were synthesized in a few steps and very good
Active and Recyclable Catalytic Synthesis of Indoles by Reductive Cyclization of 2-(2-Nitroaryl)acetonitriles in the Presence of Co–Rh Heterobimetallic Nanoparticles with Atmospheric Hydrogen under Mild Conditions
作者:Isaac Choi、Hyunho Chung、Jang Won Park、Young Keun Chung
DOI:10.1021/acs.orglett.6b02659
日期:2016.11.4
cobalt–rhodium heterobimetallic nanoparticle-catalyzed reductive cyclization of 2-(2-nitroaryl)acetonitriles to indoles has been achieved. The tandem reaction proceeds without any additives under the mild conditions (1 atm H2 and 25 °C). This procedure could be scaled up to the gram scale. The catalytic system is significantly stable under these reaction conditions and could be reused more than ten times without
钴-铑异双金属纳米粒子催化的2-(2-硝基芳基)乙腈还原环化成吲哚。在温和条件下(1 atm H 2和25°C),串联反应在没有任何添加剂的情况下进行。该过程可以按比例放大至克级。在这些反应条件下,催化体系非常稳定,可以重复使用十次以上,而不会损失催化活性。