Magnetic core–shell titanium dioxide nanoparticles as an efficient catalyst for domino Knoevenagel–Michael-cyclocondensation reaction of malononitrile, various aldehydes and dimedone
Magnetic core–shell titaniumdioxide nanoparticles (Fe3O4@SiO2@TiO2) were efficiently used for the preparation of tetrahydrobenzo[b]pyran derivatives via a one-pot three component condensation reaction of various aldehydes, dimedone and malononitrile at 100 °C under solvent-free conditions. The catalyst was synthesized and characterized by several techniques including X-ray diffraction (XRD), transmission
磁性核-壳二氧化钛纳米颗粒(Fe 3 O 4 @SiO 2 @TiO 2)可通过各种浓度的醛,二甲酮和丙二腈的一锅三组分缩合反应有效地用于制备四氢苯并[ b ]吡喃衍生物。无溶剂条件下的℃。通过几种技术合成并表征了催化剂,包括X射线衍射(XRD),透射电子显微镜(TEM),场发射扫描电子显微镜(FESEM)和能量色散X射线光谱(EDX)。
An eco-friendly innovative halide and metal-free basic ionic liquid catalyzed synthesis of tetrahydrobenzo [b] pyran derivatives in aqueous media: A sustainable protocol
作者:Priyanka Patil、Suresh Kadam、Dayanand Patil、Paresh More
DOI:10.1016/j.molliq.2021.117867
日期:2022.1
was employed as a catalyst for the multicomponent synthesis of tetrahydrobenzo[b]pyran derivatives by the condensation of dimedone, malononitrile and various substituted aldehydes as key starting materials in aqueousmedia. Novelty, the efficacy of the catalyst, high yields of desired products, greener approach, high atom economy and use of aqueousmedia make this protocol worthwhile. The inventive idea
使用一种非常简单的方法合成了一种新型的咪唑基高效、可回收和可重复使用的碱性离子液体 [PEMIM][OH]。该离子液体用作多组分合成四氢苯并[ b]的催化剂]吡喃衍生物,由二甲酮、丙二腈和各种取代的醛缩合而成,作为水性介质中的关键起始原料。新颖性、催化剂的功效、所需产品的高产率、更环保的方法、高原子经济性和水性介质的使用使该协议值得。采用卤化物和不含金属的离子液体催化剂的发明理念将其确立为可持续的过程。该协议还展示了通过避开柱子和重结晶技术来经济高效地分离纯、高产所需产品。提出了形成四氢苯并 [ b ] 吡喃的合理机制。通过使用各种分析技术,如 FTIR、1H NMR、13 C NMR、DEPT-135、LC-Mass、元素、HSQC、HPLC、TG-DSC、TG-DTG 和单晶 XRD 分析。
Silica sulfuric acid (SSA) was used as efficient catalyst for the synthesis of 4Hbenzo[
b]pyran derivatives via the one-pot three-component condensation of aromatic aldehyde (1),
5,5-dimethyl-1,3-cyclohexanedione (2a) or 1,3-cyclohexandione (2b) and malononitrile (3) in aqueous
media with high yields. The luminescence of products was studied in detail.
Efficient and green synthesis of 4<i>H</i>-pyran derivatives under ultrasound irradiation in the presence of K<sub>2</sub>CO<sub>3</sub> supported on acidic montmorillonite
作者:Dung Duc Pham、Giang Vo-Thanh、Thach Ngoc Le
DOI:10.1080/00397911.2017.1342844
日期:2017.9.17
ABSTRACT Acid-treated montmorillonite coating with K2CO3 is used as a catalyst for an efficient, rapid, one-pot synthesis of 4H-pyran derivatives in good yield under ultrasonic irradiation. The catalyst is environmentally benign, easy handling, nontoxic, stable in air, and inexpensive. GRAPHICAL ABSTRACT