Cobalt ferrite encapsulated in a zwitterionic chitosan derived shell: An efficient nano-magnetic catalyst for three-component syntheses of pyrano[3,2-<i>c</i>
]quinolines and spiro-oxindoles
作者:Fatereh Asghari-Haji、Kurosh Rad-Moghadam、Nosrat O. Mahmoodi、Tayyebeh Tonekaboni、Najmeh Rahimi
DOI:10.1002/aoc.3891
日期:2017.12
nano‐magnetic core‐shell composite fabricated of a unique zwitterionicchitosan‐derived coating and cobaltferrite core was found to be a green and reusable heterogeneous catalyst for efficient synthesis of pyrano[3,2‐c]quinoline and spiro‐oxindole derivatives in high to excellent yields. Due to having negative charges at its outermost layer and a high magnetization, the catalyst is finely dispersed
由独特的两性离子壳聚糖衍生的涂层和钴铁氧体磁芯制成的纳米磁性核-壳复合物被发现是一种绿色且可重复使用的非均相催化剂,可高效合成吡喃并[3,2- c ]喹啉和螺-吲哚衍生物高到优异的产量。由于在其最外层具有负电荷并具有高磁化强度,因此该催化剂可以精细地分散在乙醇中,并且可以通过使用简单的外部磁体轻松地从反应混合物中分离出来。它相当稳定,可以重复使用多次,而催化活性没有明显损失。
Ambient synthesis of spiro[4H-pyran-oxindole] derivatives under [BMIm]BF4 catalysis
作者:Kurosh Rad-Moghadam、Leila Youseftabar-Miri
DOI:10.1016/j.tet.2011.05.077
日期:2011.8
A simple and efficient one-pot approach for assembling some fused spiro[4H-pyran-oxindole] heterocycles by means of three-component reactions between isatins, malononitrile or ethyl cyano-acetate, and 1,3-dicarbonyl compounds is reported. The combinatorial syntheses were achieved for the first time without applying extra activation energy at ambient temperature while making use of [BMIm]BF4 as an ionic liquid catalyst. Good functional group tolerance and broad scope of usable substrates are other prominent features of the present methodology. (C) 2011 Elsevier Ltd. All rights reserved.