A clean and expedient synthesis of spirooxindoles in aqueous media catalyzed over nanocrystalline MgO

Sulfonic acid supported on Fe2O3/VO2 nanocatalyst: A highly efficient and reusable nanocatalyst for synthesis of spirooxindole derivatives

“…Various catalysts including carbon-SO3H [14], magnesium oxide (MgO) [15], ZnS NPs [16], triethylbenzyl ammonium chloride (TEBA) [17],…”

Efficient and green pathway for one-pot synthesis of spirooxindoles in the presence of CuO nanoparticles

“…The need to develop synthetic methods for the preparation of these heterocycles has attracted the attention of many scientists. Therefore, different catalysts have been used to synthesize these structures, such as guanidinefunctionalized magnetic nanoparticles (12), MgO nanoparticles (13), nickel chloride (14), p-TSA (15,16), HAuCl 4-·3H 2 O (17), cesium fluoride (18), L-proline (19) (22) and triphenylphosphine (23).…”

Synthesis of spirooxindole pyrimidines catalyzed by silica-bonded N-propyltriethylenetetramine as a recyclable solid base catalyst in aqueous medium

“…Among them, the one-pot condensation reaction of isatin and activated methylene reagent could readily afford various spirooxindole pyramidine structures and has attracted wide attention, and this type of reaction has been achieved by a number of different catalysts and conditions, such as InCl 3 [43], electrochemical methods [44], triethylbenzylammonium chloride (TEBA) [45], Et 3 N [46], tetrabutylammonium fluoride (TBAF) [47], NH 4 Cl [48], lipase [4], p-TSA [49], ZnS nanoparticles [50], NaCl under sonication [51], butylmethylimidazolium tetrafluoroborate ([BMIm]BF 4 ) [52], amino-functionalized SBA-15 [53], CaCl 2 under ultrasonic irradiation [54], piperidine under ultrasonic irradiation [55], nanocrystalline MgO [56], gluconic acid [57], MnFe 2 O 4 nanoparticles [58], 1,8-diazabicyclo [5.4.0]undec-7-ene (DBU) [59], ethylenediammonium diformate (EDDF) [60], and sulfated choline based heteropolyanion [61] which some of them suffer from technical intricacy and generation of mixtures of pyrans and unsaturated nitriles.…”