Practical and efficient synthesis of tetrahydrobenzo[b]pyran using caffeine supported on silica as an ionic liquid solid acid catalyst
作者:Mohammad Bakherad、Ali Keivanloo、Elmira Moradian、Amir H. Amin、Rahele Doosti、Mahsa Armaghan
DOI:10.1007/s13738-018-1468-y
日期:2018.12
The catalyst prepared was then characterized by the FT-IR spectroscopy, TGA, EDX, and SEM techniques. It was found that this heterogeneous catalyst was a highly efficient one for the synthesis of tetrahydrobenzo[b]pyrans in good-to-high yields, and could be recovered by a simple filtration of the reaction solution and reused for five consecutive runs. The attractive features of this method are simple
新型催化剂二氧化硅-咖啡因硫酸氢盐[SiO 2 -caff。] HSO 4可以方便地由市售的3-氯丙基三乙氧基硅烷固定在二氧化硅上,然后与咖啡因反应制得。然后通过FT-IR光谱,TGA,EDX和SEM技术表征制备的催化剂。发现该非均相催化剂是用于以高至高收率合成四氢苯并[ b ]吡喃的高效催化剂,并且可以通过简单过滤反应溶液进行回收并将其重复使用五次。该方法的吸引人的特征是操作简单,反应干净,后处理容易,使用可重复使用的催化剂以及进行多组分反应。
Convenient selective synthesis of 5,7,8,9-tetrahydro-4H,6H-chromeno[2,3-d][1,3]oxazin-4-ones
作者:Yu. M. Litvinov、A. M. Shestopalov
DOI:10.1007/s11172-010-0037-z
日期:2009.2
A method for the synthesis of 5,7,8,9-tetrahydro-4H,6H-chromeno[2,3-d][1,3]oxazin-4-ones was developed. The method involves acid-catalyzed acylation of substituted ethyl 2-amino-4-aryl-5-oxo-5,6,7,8-tetrahydro-4H-chromene-3-carboxylates with acetic anhydride.
Copper‐amine complex immobilized on nano NaY zeolite as a recyclable nanocatalyst for the environmentally friendly synthesis of 2‐amino‐4
<i>H</i>
‐chromenes
catalytic activity of the synthesized nano-sample was evaluated in a three-component synthesis of 2-amino-4H-chromene derivatives, which resulted in high reaction yields and short reaction times under green conditions. The catalyst is separated by filtration and can be reused for at least seven consecutive runs without significant loss of catalytic activity. The nature of the supported [2-(3-[(2-ami