Novel nano-titania embedded on graphite (nano-TiO2@Cg) as an efficient, eco-friendly, and recyclable catalyst for one-pot, solvent-free synthesis of 4-aryl-3,4-dihydroquinolin-2(1H)-ones, 3-methyl-4-aryl/alkyl-2,4,5,7-tetrahydropyrazolo[3,4-b]pyridin-6-ones, and coumarin-3-carboxylic esters
作者:Kobra Nikoofar、Fatemeh Molaei Yielzoleh
DOI:10.1007/s11164-018-3560-4
日期:2018.12
three-component reaction of Meldrum’s acid, aromatic amines (5-methylpyrazol-3-amine), and various aromatic aldehydes to form 4-aryl-3,4-dihydroquinolin-2-(1H)-ones and 3-methyl-4-aryl/alkyl-2,4,5,7-tetrahydropyrazolo[3,4-b]pyridin-6-ones, respectively. The catalytic activity has also examined for the preparation of coumarin-3-carboxylic esters from Meldrum’s acid, salicylaldehydes, and alcohols successfully
摘要 工业锐钛矿相纳米TiO 2和石墨(nano-TiO 2 @C g)通过简单的步骤合成了一种新型的酸催化剂,并通过傅里叶变换红外光谱,能量色散X射线光谱,热重分析,现场表征发射扫描电子显微镜和电位滴定技术。它已被用作便利的纳米催化剂来加速Meldrum酸,芳族胺(5-甲基吡唑-3-胺)和各种芳族醛的一锅法,无溶剂三组分反应以形成4-芳基-3,4-二氢喹啉-2-(1 H)-ones和3-甲基-4-芳基/烷基-2,4,5,7-四氢吡唑并[3,4- b] pyridin-6-ones。还成功地检测了由Meldrum的酸,水杨醛和醇制备香豆素3-羧酸酯的催化活性。低催化剂装载量,清洁工艺,不使用任何有害溶剂,简便的后处理程序,四次运行中纳米催化剂的可重复使用性和可回收性,无活性损失,产物收率高以及使用多种底物是一些突出亮点报告的协议。 图形概要