Zirconium@guanine@MCM‐41 nanoparticles: An efficient heterogeneous mesoporous nanocatalyst for one‐pot, multi‐component tandem Knoevenagel condensation–Michael addition–cyclization Reactions

Abstract

MCM-41-supported nanoscale guanine bonded with Zr (IV) was prepared using sol-gel method and characterized by FT-IR, Raman, XRD, BET, TGA, EDX, ICP, AAS, X-Ray mapping, SEM and TEM techniques. This compound was employed as an efficient, chemoselectivity and green heterogeneous catalyst in order to prepare a series of benzo[a]benzo[6,7]chromeno[2,3-c] phenazine and spiro[benzo[a]benzo[6,7]chromeno[2,3-c] phenazine] derivatives by one-pot, four-component domino reaction from the 2-hydroxy-1,-4-naphthoquinone, benzene-1,2-diamines, 2-hydroxy-1,4-naphthoquinone and carbonyl compounds in PEG, at 100 C and, also, Bis (pyrazolyl) methane derivatives using aldehydes and 3-Methyl-1-phenyl-5-pyrazolone in ethanol under reflux condition. Results indicated that all products were synthesized in short reaction times and high yields in the ranges 78-99%. The Zr-guanine-MCM-41 can be recycled four runs without any significant loss of its catalytic activity. In addition, the stability of the catalyst was confirmed by metal leaching, heterogeneity tests, SEM and FT-IR techniques. K E Y W O R D S benzo[a]benzo[6,7]chromeno[2,3-c]phenazines, Bis (pyrazolyl)methanes, Spiro[benzo[a] benzo[6,7]chromeno[2,3-c] phenazine], Tandem Knoevenagel condensation-Michael additioncyclization, Zr-guanine-MCM-41

Boehmite@SiO2@ Tris (hydroxymethyl)aminomethane‐Cu(I): a novel, highly efficient and reusable nanocatalyst for the C‐C bond formation and the synthesis of 5‐substituted 1H‐tetrazoles in green media

“…[44][45][46][47] On the other hand, easy separation and consecutive reusability of heterogeneous catalyst makes their consideration for industrial and laboratorial aims. [48,49] Due to the unique dimensions and size, physical properties, easy recyclability, large specific surface area, [5,6,49,50] make them as a perfect candida in catalysis science. [13,[51][52][53][54][55] During the past years, the use of recyclable heterogeneous catalysts (prepared by supporting solid support via homogenous precursors) has received great attention in organic synthesis.…”

“…[13,[51][52][53][54][55] During the past years, the use of recyclable heterogeneous catalysts (prepared by supporting solid support via homogenous precursors) has received great attention in organic synthesis. [5,6,47,49,50,56] In recent years boehmite have attracted viable attention as potential solid support for the nano scaled heterogenization of homogeneous catalysts. [6] This nano structural material can be prepare from inexpensive, commercially available and non-toxic substrates in aqueous media under air conditions.…”

Pd(0)‐guanidine@MCM‐41: a very effective catalyst for rapid production of bis (pyrazolyl)methanes

“…Nanoparticles can substitute conventional materials, and serve as active and stable heterogeneous catalysts or as support materials for various catalytic groups . Due to their small sizes, catalytic‐active nanoparticles have higher surface areas and increased exposed active sites, and thereby improved contact areas with reactants, akin to those of homogeneous catalytic systems …”

L‐lysine‐Pd Complex Supported on Fe3O4MNPs: a novel recoverable magnetic nanocatalyst for Suzuki C‐C Cross‐Coupling reaction

“…[ 7,31,33,34 ] One way to solve these problems is the heterogenization of the homogeneous catalysts on solid supports. [ 20,35–38 ] One of the best methods for the preparation of nanocatalysts is the synthesis of heterogeneous catalysts by suitable supports such as silica nanoparticles, [ 39 ] SBA‐15, [ 24,38,40–46 ] SBA‐16, [ 47 ] MCM‐41, [ 44,48–51 ] MCM‐48, [ 52 ] FSM‐16, [ 53–55 ] alumina, [ 56 ] heteropoly acids, [ 57 ] graphene oxide, [ 58,59 ] Multiwall carbon nanotubes (MWCNTs), [ 60 ] Boehmite, [ 31 ] polymers, [ 61 ] peptide nanofibers, [ 62 ] Fe 3 O 4 @SiO 2, [ 63 ] or ferrites nanoparticles. [ 7,5,20–23,32,37,64 ] Among various supports, iron oxide magnetic nanoparticles (Fe 3 O 4 ‐MNPs) have attracted more attention due to their significant advantages i.e.…”