Brønsted acidic hydrogensulfate ionic liquid immobilized SBA-15: [MPIm][HSO4]@SBA-15 as an environmentally friendly, metal- and halogen-free recyclable catalyst for Knoevenagel–Michael-cyclization processes

Functionalization of MCM-22 by Dual Acidic Ionic Liquid and Its Paraffin Absorption Modulation Properties

“…1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 immobilization, MCM-22-IL showed an initial weight loss of 2.4% up to 180 °C due to the adsorbed water water as well as the loss of C 2 H 5 OH upon the further condensation of unreacted ethoxy groups 18 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 The acid amounts of MCM-22 and MCM-22-IL were measured by amine titration method. )…”

“…Besides, solid acid catalysts have been investigated but they have not yet to achieve commercial application due to its rapid catalyst decay 15 . Sadegh Rostamnia summarized many literatures and found that most silica mesostructure-supported catalysts have beneficial properties for catalysis, stereoselectivity, and green reaction delivery 16 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 immobilizing the homogenous precursors on solid support is one of the most important routes for developing novel heterogeneous catalysts, which could provide advantages during separation and reusability processes 16,17,18 …”

Novel magnetic nanoparticles with ionic liquid tags as a reusable catalyst in the synthesis of polyhydroquinolines

“…1 [19]. Due to the above listed excellent therapeutic applications of the 1,4-dihydropyridine derivatives, synthetic chemists have explored several protocols for the synthesis of them using different reaction conditions and varied catalytic systems as follows: Yb(OTf) 3 [20], [pyridine-SO 3 H]Cl [21], [Dsim]HSO 4 [22], Triton X-100 in water [23], TiO 2 NPs [24], SnO 2 NPs [25], silica-bonded imidazolium-sulfonic acid chloride [26], [2-MPyH]OTf [27], SBA-15/SO 3 H [28], Ninanoparticles [29], IL-HSO 4 @SBA-15 [30], Baker's yeast [31], Lproline [32], and [bmim]BF 4 [33]. Although the reported methods offer several merits and provide improvements for the synthesis of the target molecules, many of these protocols need longer reaction times, hard reaction conditions, using unsafe organic solvents, and drastic workups.…”

Design and characterization of nano-silica-bonded 3-n-propyl-1-sulfonic acid imidazolium chloride {nano-SB-[PSIM]Cl} as a novel, heterogeneous and reusable catalyst for the condensation of arylaldehydes with β-naphthol and alkyl carbamates

“…The immobilization of IL catalysts can extensively expand their applications in addition to the advantages of their homogeneous counterparts, their application, handling, isolation, and reusing process make them superior to other catalysts. From the economic point of view, it is highly favorable to minimize the amount of IL applied in the potential transformations [15][16][17][18][19][20][21], and alternatively solid-supported acidic ILs have been applied as remarkable heterogeneous catalysts for a myriad of acid-catalyzed transformations [15][16][17][18][19][20][21].…”