Expanded perlite: an inexpensive natural efficient heterogeneous catalyst for the green and highly accelerated solvent-free synthesis of 5-substituted-1H-tetrazoles using [bmim]N₃ and nitriles

Abstract

A versatile, green and highly accelerated protocol for preparing 5-substituted-1H-tetrazoles is reported using expanded perlite as a heterogeneous catalyst.

Effect of different filter aids used in cake filtration process on the removal of suspended solids in anaerobically digested palm oil mill effluent (POME)

“…5(a). It is similar to the observation of perlite reported by Jahanshahi and Akhlaghinia [38] in which the surface layer was highly porous. Therefore, the fine porous structure of perlite enabled better retention of suspended solids by its high removal of TSS and turbidity in the filtered digestate.…”

Experimental Investigations on the Performances of Composite Building Materials Based on Industrial Crops and Volcanic Rocks

“…The microscopic image presented in Figure 2b illustrates the exterior porous surface of a perlite grain. According to Reference [36], the unexpanded perlite can increase volume by 10 to 20 times more, when heated over 700 • C, becoming an expanded perlite. The water molecules from the initial stage evaporate during the heating process, cracks appear as a consequence of the steam leak, therefore the resulting cavities will define the perlite structure [34,36,37].…”

“…According to Reference [36], the unexpanded perlite can increase volume by 10 to 20 times more, when heated over 700 • C, becoming an expanded perlite. The water molecules from the initial stage evaporate during the heating process, cracks appear as a consequence of the steam leak, therefore the resulting cavities will define the perlite structure [34,36,37]. The X-ray diffraction graph of perlite, from Reference [19], resembles the curve shape of powder perlite studied in Reference [38], indicating an amorphous structure already identified in previous studies [39,40].…”

Synthesis of α‐Aminonitriles and 5‐Substituted 1H‐Tetrazoles Using an Efficient Nanocatalyst of Fe3O4@SiO2–APTES‐supported Trifluoroacetic Acid

“…An isocyanide‐based multicomponent reaction (Passerini‐azide and Ugi‐azide reactions) is also used for the synthesis of tetrazoles . According to the literature, 5‐substituted and 1‐substituted 1 H ‐tetrazoles have been synthesized using different azide agents (NaN 3 , TMSN 3 , and [bmim]N 3 ) and catalyzed by different systems such as SnCl 2 –SiO 2 , InCl 3 , ZnS nanoparticles (NPs) , Pt NPs@rGO , Cu–MCM‐41 , MCM‐41–SO 3 H , SiO 2 –H 3 BO 3 , Fe 3 O 4 @chitin , and boehmite–Ni . However, the reported works suffer from serious drawbacks such as using harmful organic solvents [e.g., dimethylformamide (DMF)], operating at elevated temperatures (above 100°C), requiring excessive time to reaction completion, and, in some cases, poor catalyst recyclability and reusability.…”