The first catalytic application of oxidized carbon nanotubes in a four-component synthesis of fused heterocycles

CoFe2O4@SiO2‐PA‐CC‐Guanidine MNPs as an Efficient Catalyst for the One‐Pot, Four‐Component Synthesis of Pyrazolopyranopyrimidines

“…In recent years, synthesis of fused heterocycle compounds via multicomponent reactions (MCRs) as an efficient and eco‐friendly protocol has enhanced. Multicomponent reactions have advantages such as high atom‐economy, high stereoselectivity, low time and cost and save energy . In the past decades, the use of nanoparticles as heterogeneous catalysts in the organic synthesis was increased.…”

“…Multicomponent reactions have advantages such as high atom-economy, high stereoselectivity, low time and cost and save energy. [16,17] In the past decades, the use of nanoparticles [18] as heterogeneous catalysts in the organic synthesis was increased. Activity of heterogeneous catalysts [19] in compare to homogeneous catalysts [20] is less but extraction of these catalysts from the reaction mixture is very comfort.…”

Green synthesis of pyrazolopyranopyrimidinone and pyranopyrazole derivatives using porphyrin‐initiated amine‐functionalized PolyBCMO dendritic polymer as sonocatalyst

“…Only a few methods for the synthesis of pyrazolopyranopyrimidinones using base catalysts were reported in the literature, including the four‐component reaction between ethyl acetoacetate, hydrazine hydrate, aromatic aldehyde, and barbituric acid . This procedure has many limitations including toxic solvent, long reaction time, and low product yield.…”

Ultrasound-promoted green synthesis of 1,4-dihydropyridines using fuctionalized MWCNTs as a highly efficient heterogeneous catalyst

“…Various catalysts were used for the synthesis of these compounds such as ionic liquid (21), tetrabutylammonium hydrogen sulfate (22), I 2 (23), cellulose sulfuric acid (24), HY-Zeolite (25), nano-Fe 3 O 4 (26) nano-Fe 2 O 3 (27), SnCl 4 -functionalized nano-Fe 3 O 4 encapsulated-silica particles (28), ZnFe 2 O 4 nanopowder (29), 3D printed α-Al 2 O 3 (30), Alginic Acid (31), Fe 3 O 4 @SiO 2 (32), magnetic nanoparticle supported Ni 2+ -containing ionic liquid (33) and metal triflate (34). Recently, the direction of science and technology has been shifted towards eco-friendly and natural product resources (such as natural biopolymers) that are attractive candidates in the search for solid support catalysts (24,(35)(36)(37)(38)(39)(40)(41)(42)(43)(44)(45)(46). Also in recent years, ultrasound has been used to accelerate the chemical reactions proceed via the formation and collapse of transient cavitation bubbles.…”

“…Carbon nanotubes (CNTs) with exceptional physical properties such as high specific surface area, excellent electron conductivity incorporated with the good chemical inertness and relatively high oxidation stability is a promising support material for a heterogeneous catalyst (35,36,51,52). In view of recent surge in the use of heterogeneous catalysts, we wish to report a simple, convenient and efficient method for the preparation of 1,4-DHPs in the presence of multiwalled carbon nanotubes (MWCNTs@meglumine), as a heterogeneous inexpensive, highly efficient and reusable catalyst under ultrasonic irradiation (Scheme 1).…”