Silica‐bonded S‐Sulfonic Acid: A Recyclable Catalyst for the Synthesis of Trisubstituted Imidazoles under Solvent‐free Conditions

Abstract

Trisubstituted imidazoles have been synthesized in high yields in the presence of silica-bonded S-sulfonic acid as a catalyst. The reaction was carried out at 130 ℃ under solvent-free conditions. The reaction work-up is simple and the catalyst is easily separated from the products by filtration.

An efficient catalytic method for the synthesis of pyrido[2,3‐d]pyrimidines as biologically drug candidates by using novel magnetic nanoparticles as a reusable catalyst

“…Niknam et al . have reported the synthesis and application of a bulky, amorphous silica‐bonded S ‐sulfonic acid (SBSSA) as a reusable catalyst for the preparation of aromatic 1,1‐diacetates, quinoxalines, 4,4 ′ ‐(arylmethylene)bis(1 H –pyrazol‐5‐ols), α ‐amino nitriles, 1,8‐dioxo‐decahydroacridines, 1,8‐dioxo‐octahydroxanthenes, bis‐indolylmethanes, silylated alcohols, trisubstituted imidazoles, 2,3‐dihydroquinazolin‐4(1 H )‐ones, and 2‐aryl‐1‐arylmethyl‐1 H ‐1,3‐benzimidazoles…”

Preparation of Silica‐bonded Propyl‐diethylene‐triamine‐N‐sulfamic Acid as a Recyclable Catalyst for Chemoselective Synthesis of 1,1‐Diacetates

“…29 Several types of solid sulfonic acid functionalized silica (both amorphous and ordered) have been synthesized and applied as an alternative to traditional sulfonic acid resins and homogeneous acids in catalyzing chemical transformations. [30][31][32][33][34][35][36] In continuation of our studies on the design and application of solid acid catalysts in organic transformations, 31-36 herein, we describe the preparation and application of silica-bonded propyldiethylene-triamine-N-sulfamic acid (SPDTSA) as a new and recyclable catalyst for the synthesis of 1,1-diacetates (Scheme 1).…”

Silica-Bonded N-Propyl Diethylenetriamine Sulfamic Acid as a Recyclable Solid Acid Catalyst for the Synthesis of α-Aminonitriles

“…Several types of solid sulfonic acid-functionalized silica (both amorphous and ordered) have been synthesized and used as an alternative to traditional sulfonic acid resins and homogeneous acids to catalyze chemical transformations [20][21][22][23][24][25][26][27][28][29]. In continuation of our studies on the design and application of solid acid catalysts in organic transformations [21][22][23][24][25][26][27][28][29], herein, we describe the application of silica-bonded N-propyl diethylenetriamine sulfamic acid (SBPDSA) as recyclable catalyst for the synthesis of α-aminonitriles.…”