Tungstophosphoric acid/mesoporous silicas as suitable catalysts in quinoxaline synthesis

In situ preparation of a ferric polymeric aluminum chloride–silica gel nanocatalyst by mechanical grinding and its solid-phase catalytic behavior in organic synthesis

“…Four classes of nitrogen-containing compounds such as 3alkylindole derivatives, 21,22 quinoxaline derivatives, 23,24 benzimidazole derivatives, 25,26 and b-amino alcohol derivatives 27,28 are widely used in the synthesis of pharmaceutical intermediates. The research on the green and efficient synthesis of these products from simple chemical raw materials has great practical value, and the use of mechanochemical methods to produce the above compounds will greatly reduce the generation of toxic waste during the production process.…”

Reusable nano-catalyzed green protocols for the synthesis of quinoxalines: an overview

“…Then, the carbocation intermediate is obtained by dehydration and elimination of the protons to give the quinoxaline, and the catalyst is regenerated (Schemes 32 and 33). 121,122 The silica-based nanosphere-graphene oxide (SiO 2 -GO) hybrid was prepared by Shitre and co-workers. Further, this material was characterized by TEM, FTIR, EDS and XRD.…”

Hantzsch reaction using copper nitrate hydroxide-containing mesoporous silica nanoparticle with C3N4 framework as a novel powerful and reusable catalyst

“…The well-defined pore structure of porous silica can function as a molecular sieve at small sizes and may ultimately be utilized to control substrate access to the catalyst which is very important in improving/tuning the selectivity 42 , 43 . These materials have proved their versatility in separation 44 , sensor 45 , drug delivery 46 , and catalysis 47 . Carbon nanostructures are especially of attention owing to their promising properties including high specific surface area, excellent mechanical strength, high conductivity, and fascinating physicochemical features.…”