Magnetic Nanoparticles (CoFe₂O₄)‐Supported Phosphomolybdate as an Efficient, Green, Recyclable Catalyst for Synthesis of β‐Hydroxy Hydroperoxides

Synthesis of furo[3,2-c]coumarins under microwave irradiation using nano-CoFe2O4@SiO2–PrNH2 as an efficient and magnetically reusable catalyst

“…CoFe 2 O 4 @SiO 2 -PrNH 2 nanoparticles were prepared according to a method reported in the literature with some modifications. 21 CoFe 2 O 4 nanoparticles were prepared by a chemical co-precipitation method using FeCl 3 ·6H 2 O and CoCl 2 ·6H 2 O as precursors. FeCl 3 ·6H 2 O (5.40 g, 0.02 mol) and CoCl 2 ·6H 2 O (2.38 g, 0.01 mol) were dissolved in distilled water (100 ml).…”

Nano-catalysts with magnetic core: sustainable options for greener synthesis

“…The incorporation of a second metal serves to futher expand the catalytic abilities of Fe and incorporation of oxides on to silica has been utilized for the biodiesel production [37]. Supporting various ligands on the magnetic nanoparticles facilitates synthesis of several chemical entities with sustainable advantages, predominant being the magnetic separation and recyclability aspects [38,39]. Incorporation of copper provides an easy preparation of propargylamines via a multicomponent reaction [40] and asymmetric nanocatalysis is facilitated by support of heterocyclic carbenes as chiral modifiers [41].…”

Silica-coated magnetic NiFe2O4 nanoparticles-supported H3PW12O40; synthesis, preparation, and application as an efficient, magnetic, green catalyst for one-pot synthesis of tetrahydrobenzo[b]pyran and pyrano[2,3-c]pyrazole derivatives

“…Furthermore, HPA are capable of protonating and activating substrates, and are sometimes more effective than conventional inorganic acids and traditional acid catalysts. Because the high solubility of these materials often makes their separation from the reaction mixture difficult, immobilization of HPA on supports with high surface area facilitates their use as catalysts in a variety of heterogeneous reactions [1][2][3].…”

“…Catalysts used for one-pot, three-component reactions include piperidine [21], hexadecyltrimethyl ammonium bromide (HTMAB) [22], sodium bromide [23], ionic liquids [24][25][26][27][28][29], tetramethylammonium hydroxide [30], diammonium hydrogen phosphate [31], organocatalysts [32], sodium selenite [33], tetrabutylammonium bromide (TBAB) [34,35], polyaniline-silica gel [36], alum [KAl(SO 4 ) 2 Á12H 2 O] [37], rare earth perfluorooctanoates, e.g. Re(PFO) 3 [38], Caro's acid [39], amines or amino acids [40], potassium phosphate [41], PPA-SiO 2 [42], microwave irradiation [43], BF 3 ÁOEt 2 [44], magnetic core-shell titanium dioxide nanoparticles (Fe 3 O 4 @SiO 2 @TiO 2 ) [45], NH 4 H 2 PO 4 -Al 2 O 3 [46], DABCO-EtOH [47], TPPA [48], t-BuOK-t-BuOH [49], L-proline under ultrasound irradiation [50], and silica coated magnetitepolyoxometalate nanoparticles (Fe 3 O 4 @SiO 2 @NH-NH 2 -H 3 PW 12 O 40 ) [51]. Many of these methods suffer from one or more limitations, for example low yields, use of expensive reagents, long reaction times, tedious work-up procedures, and cooccurrence of several side reactions.…”