DABCO‐modified super‐paramagnetic nanoparticles as an efficient and water‐compatible catalyst for the synthesis of pyrano[3,2‐c:5,6‐c']dichromene‐6,8‐dione derivatives under mild reaction conditions

Abstract

In this paper, a novel catalyst is introduced based on the immobilization of 1,4‐diazabicyclo[2.2.2] octane (DABCO) on super‐paramagnetic iron oxide nanoparticles. For the synthesis of the catalyst, silica‐magnetic iron oxide core‐shell nanoparticles were first functionalized by (3‐chloropropyl)trimethoxysilane. The functionalized silica‐magnetic iron oxide core‐shell nanoparticles then reacted with DABCO to form the final catalyst. The catalyst was characterized by scanning electron microscopy, vibrating‐sample magnetometer, thermogravimetric analysis, X‐ray photoelectron spectroscopy and Fourier‐transform infrared spectroscopy. This catalyst was used for the synthesis of pyrano[3,2‐c:5,6‐c']dichromene‐6,8‐dione derivatives. Several starting materials were used, and all of them led to the desired products in high isolated yields (19 examples). The catalyst also showed very good reusability in the reaction.

A decennary update on applications of metal nanoparticles (MNPs) in the synthesis of nitrogen- and oxygen-containing heterocyclic scaffolds

“…Panahi et al synthesized an L-cysteine-tagged magnetite NP (LCMNP) catalyst via the vinylation of Fe 3 O 4 @SiO 2 NPs followed by graing with L-cysteine in the presence of azobisisobutyronitrile (AIBN) as a reducing agent. Using this catalyst, the three-component reaction of substituted indoles (88g), malononitrile (29a) and substituted salicylaldehydes (21f) for the synthesis of 2-amino-4H-chromenes (243, Scheme 131), 257 and Kabachnik-Fields reaction of substituted aldehydes (244), diethyl phosphonates (245) and anilines (6b) for the synthesis of anti-cancer a-aminophosphonates possessing the nitrogenous heterocycles theophylline, benzimidazole, and adenine (246, Scheme 132) were successfully achieved in reasonable yields. 258 They also evaluated 246 for its anti-cancer activity against the Jurkat cancer cell line.…”

“…The catalyst was separated by magnetic decantation and recycled several times.Iron oxide NPs prepared via co-precipitation of Fe 2+ and Fe 3+ salts in alkaline medium were loaded with silica and 1-butyl-3-(3-trimethoxypropyl)-1H-imidazol-3-ium chloride to prepare ILloaded superparamagnetic MNPs (IL-SiO 2 @MNP, Scheme 120) by Mahadvi et al244 These recyclable MNPs were used for the synthesis of 6H-chromeno[4,3-b]quinolin-6-ones (226) via the multi-component reaction of 4-hydroxycoumarin (20a), aniline or 3,4-methylenedioxyaniline (6f) and substituted benzaldehydes (21a). Further, they reported the synthesis of pyrano[3,2c:5,6-c 0 ]dichromene-6,8-diones from 4-hydroxy coumarin and benzaldehydes using DABCO-modied super-paramagnetic iron oxide NPs (SPIONs) in aqueous ethanol at 80 C 245.…”

Sulfonic Acid Functionalized Magnetic Starch as an Efficient Catalyst for the Synthesis of Chromeno[4,3‐b]quinoline‐6,8(9H)‐dione Derivatives

“…The synthesis of chromeno [4,3-b]quinoline-6,8(9H)dione derivatives have been reported by multicomponent reactions. [35][36][37][38][39][40] Chromeno [4,3-b]quinoline-6,8(9H)-diones are Scheme 1. Starch/SPION@SO 3 H catalyzed synthesis of chromeno [4,3-b]quinoline-6,8(9H)-dione derivatives.…”

Copper Supported onto Magnetic Nanoparticles as an Efficient Catalyst for the Synthesis of Triazolobenzodiazepino[7,1‐b]quinazolin‐11(9H)‐ones via Click N‐Arylation Reactions

“…[30][31][32][33] In addition, is has been observed that immobilization of the catalysts onto nanoparticles could facilitate the reusability of the catalysts and at the same time increase the activity and the efficiency of the catalysts. [34][35][36][37][38][39]52] Among various nanoparticles, which are used as support for the immobilization of the catalysts, magnetic nanoparticles are of high interest, due to their unique properties. [40][41][42][43][44][45] Superparamagnetic iron oxide nanoparticles (SPION) are significant support, due to their chemical and thermal stability and ease of functionalization.…”