(α-Fe2O3)-MCM-41 as a magnetically recoverable nanocatalyst for the synthesis of pyrazolo[4,3-c]pyridines at room temperature

Synthesis of heterocycles and fused heterocycles catalyzed by nanomaterials

“…The prepared nanocatalyst was also shown to have excellent and green catalytic activity in the synthesis of imidazo[1,2-a]pyridines 83a-y via the one-pot reaction of 2-aminopyridines 9, aldehydes 7 and phenylacetylene 35 in aqueous media (Scheme 55, Table 48). 99 It is worth mentioning that 3,5-dibenzylidenepiperidin-4-one with electron-withdrawing groups on the phenyl rings induce greater electronic positive charge on the corresponding β-atoms and reacted rapidly whereas electron-rich groups on the phenyl rings require longer reaction times. The Cu 2+ of CuFe 2 O 4 catalyzes the subsequent Michael addition reaction of the 6-aminouracil 86 to the α,β-unsaturated nitroalkene.…”

Fe3O4@silica‐MCM‐41@DABCO: A novel magnetically reusable nanostructured catalyst for clean in situ synthesis of substituted 2‐aminodihydropyrano[3,2‐b]pyran‐3‐cyano

“…Despite their superior features, due to poor morphology, low thermal stability, high aggregation tendency and susceptibility to oxidation of these bare materials, polymers, carbon layers and silicate materials are utilized to coat such magnetic nanoparticles. Mesoporous silicate coatings, by preventing the aggregation of nanoparticles, can improve the characteristics of magnetic nanostructures due to their biocompatibility, small nanopore size, controllable morphologies, high surface area, chemical stability and inertness, and can be widely utilized as heterogeneous catalysts in organic transformations . In order to recover the catalysts based on silica‐MCM‐41 from reaction mixtures, functionalized magnetic nanoparticles with mesoporous silica coating have been developed as a powerful tool .…”

Синтез Кластеров Оксидов Железа В Мезопорах Монодисперсных Сферических Частиц Кремнезема

“…Это затрудняет масштабное практическое применение частиц в меди-цине и катализе. Для использования частиц оксидов железа в катализе и в качестве электрохимических сенсоров было предложено размещать частицы (нано-кластеры) в пористых носителях, например, заполнять подсистему цилиндрических мезопор кремнезема типа MCM-41 водными растворами солей железа (FeCl 3 , Fe(NO 3 ) 3 ) или вводить соли железа в процессе гид-ротермального синтеза МСМ-41, с последующим тер-мическим разложением для формирования оксидных нанокластеров [8][9][10].…”