TiO₂ Nanoparticles Immobilized on Carbon Nanotubes: An Efficient Heterogeneous Catalyst in Cyclocondensation Reaction of Isatins with Malononitrile and 4‐Hydroxycoumarin or 3,4‐Methylenedioxyphenol under Mild Reaction Conditions

Abstract

TiO2 nanoparticles supported on carbon nanotubes (TiO2‐CNTs) as an efficient heterogeneous catalyst was used for the synthesis of spiro[3,4′]1,3‐dihydro‐2H‐indol‐2‐one‐2′‐amino‐5′‐oxo‐4'H,5'H‐pyrano[3′,2′‐c]chromen‐3′‐yl cyanides and spiro[3,8′]1,3‐dihydro‐2H‐indol‐2‐one‐6′‐amino‐8'H‐[1′,3′]dioxolo[4′,5′‐g]chromen‐7′‐yl cyanides via the cyclocondensation reaction of isatins with malononitrile and 4‐hydroxycoumarin or 3,4‐methylenedioxyphenol in aqueous media at room temperature. This reaction offers several sustainable and economic benefits such as high yields of products, convenient operation, and use of non‐toxic catalyst in water media.

Novel butane sulfonic acid-functionalized core–shell magnetic nanocatalysts for ultrasound-assisted coumarin synthesis

“…72 Likewise, 120 1C was found as the ideal temperature for coumarin synthesis employing Fe 3 O 4 @C@PrNH@BuSO 3 H NPs (0.03 g; 3 mol%). Next, a variety of polar and non-polar solvents were tested to identify the ideal conditions (Table 1, entries [11][12][13][14][15][16][17].…”

“…9 Heterogeneous catalysts have a significant advantage over homogeneous catalysts owing to their ease of separation from the reaction medium. [10][11][12][13][14][15][16] In addition, catalyst recovery and reusability are significantly increased. Researchers studying catalysts have focused especially on nanostructured materials because of the following special qualities: a highly dispersible, specifically designed surface, and comparatively high mechanical and thermal stability.…”

Six-component synthesis and biological activity of novel spiropyridoindolepyrrolidine derivatives: A combined experimental and theoretical investigation

“…For this reason, the mixture of two or more metals and their curing procedures permit the change of the properties of materials’ surface and optimization of the properties for a particular goal ( Zhang et al, 2012 ; Lin-Bing et al, 2015 ). Therefore, the mixture of metal oxide catalysts and nanocomposite structures of them exhibited production of heterocyclic compounds according to green rules with high efficiency ( Abdolmohammadi, et al, 2019 ; Abdolmohammadi et al, 2020a ; Kalantari et al, 2020 ; Abdolmohammadi, et al, 2021 ; Khalilzadeh et al, 2021 ). Among the metal oxide nanoparticles, Fe 3 O 4 magnetic nanoparticles (MNPs) are important because of high surface area, simple removing from reaction, and employment of it in MCRs several times.…”

“…Therefore, high-efficiency methods or actively synthesized compounds were needed for eliminating or decreasing these problems. In recent years, we studied about enhancing new and easy processes for the generation of important heterocyclic compounds ( Babizhayev et al, 2004 ; Ebrahimi, et al, 2008 ; Kassaee et al, 2010 ; Yavari et al, 2010 ; Khandan-Barani et al, 2011 ; Rustaiyan, et al, 2011 ; Rustaiyan, et al, 2011 ; Shahvelayati et al, 2012; Ezzatzadeh et al, 2012 ; Hassanabadi and Khandan-Barani, 2013 ; Masoodi, et al, 2013 ; Abdolmohammadi, 2014b ; Maghsoodlou, et al, 2014 ; Azizi et al, 2015 ; Hajinasiri et al, 2015 ; Khandan-Barani et al, 2015 ; Balar et al, 2016 ; Balar et al, 2016 ; Ghambarian et al, 2016 ; Soleimani Amiri, et al, 2016 ; Ghambarian et al, 2017 ; Koohi, et al, 2017 ; Salehi Borban et al, 2017 ; Shahvelayati et al, 2017 ; Soleimani-Amiri et al, 2018 ; Abdolmohammadi and Hossaini, 2019 ; Ghashghaee et al, 2019 ; Hekmatara et al, 2019 ; Mohammadi, et al, 2019 ; Seifi Mansour et al, 2019 ; Abdolmohammadi et al, 2020a ; Ghashghaee et al, 2020a ; Ghashghaee et al, 2020b ; Shafaei et al, 2020 ; Ghavidel, et al, 2021 ; Zare Davijani et al, 2022b ). In this research, initially, a green procedure was employed for the generation of new spiropyridoindolepyrrolidines 7 via MCRs of isatins 1 , acetyl chloride 2 , secondary amines 3 , vinilidene Meldrum’s acid 4 , primary amines 5, and malononitrile 6 in an aqueous medium at room temperature in the vicinity of Ag/Fe 3 O 4 /CdO@MWCNT MNCs as an organometallic catalyst in aqueous media at room temperature ( Scheme 1 ).…”

A PANI-Fe3O4@ZnO nanocomposite: a magnetically separable and applicable catalyst for the synthesis of chromeno-pyrido[d]pyrimidine derivatives

“…46 Pyridine is a nitrogen-containing basic heterocycle found in various synthetic and naturally occurring compounds that have been shown to possess promising agrochemical and pharmaceutical properties. 47 As a part of ongoing studies into the synthesis of biologically signicant heterocycles catalyzed by various inorganic nanosized materials, [48][49][50] we explored a low-cost and ecofriendly cyclocondensation reaction for the synthesis of 9,11-dimethyl-7aryl-6H-chromeno[3 0 ,4 0 :5,6]pyrido [2,3-d]pyrimidine-6,8,10(9H,11H)trione derivatives in the presence of water as a green solvent and a PANI-Fe 3 O 4 @ZnO nanocomposite as a applicable heterogeneous catalyst at room temperature. The synthetic pathway is presented in Scheme 1.…”