In recent years, magnetized nanoparticles got attention as efficient catalysts in organic processes. magnetite (Fe3O4) and metal-impregnated magnetite catalysts utilized to promote different reactions (direct cross β-alkylation of primary alcohols, and various multicomponent reactions)1. Nano-magnetite, utilized as a versatile support for functionalization of various catalytic systems (such as metals, organocatalysts, N-heterocyclic carbenes, and chiral catalysts) yielded recyclable catalysts for development of sustainable methodologies in green chemistry and pharmaceutically significant reactions2.Many types of magnetic nanoparticles including pure metals (Fe, Co, and Ni), alloys (CoPt3, FePt, and FeCo), iron oxides (FeO, Fe2O3, and Fe3O4) catalyzed different organic transformations3.Magnetic spinel ferrites nanoparticles (MFe2O4, where M dedicated M2+ oxidation state of metals such as Cu, Co, Ni, Zn, Mn, and etc.) are type of ceramic oxide with magnetoelectric properties. They are known as versatile catalysts in organic reactions and transformants such as dehydrogenation, oxidation, alkylation, couplings, and etc. In fact, MFe2O4 is a Lewis acid capable of accepting electrons to form covalent bonds, which activates specific groups of reactants by increasing their electrophilicity4,5,6. The magnetites and ferrites possess special characteristics such as selectivity, stability, recyclability (due to their magnetic behavior, they could be easily separated from the reaction mixture by an external magnet and reused), reactivity, and easy preparation procedures.FeAl2O4 is aluminum-iron single-phase spinel, in which Fe2+ cations occupy one eighth of the tetrahedral sites and Al3+ occupy one half of the octahedral sites. The distribution of those ions in the unit cell depends on the synthesis conditions, as some Fe2+ cations can also occupy octahedral sites7. FeAl2O4, which named also as iron aluminate and hercynite, rarely found in nature. It has been synthesized via various methods such as combustion reaction7,8, furnace heating of iron and aluminum acetylacetonate complexes9, microwave magnetic field (H-field) irradiation10, thermal treatment of mechanochemically activated (Al + Fe3O4) mixtures11, and pulsed laser ablation in liquid media technique12.Ionic liquids (ILs) are salts that usually exist in liquid form (low-melting salts with melting point below 100 °C) and consist of organic cations and organic/inorganic anions. They also nominated as molten salts, fused salts, liquids organic salts, and liquid electrolytes13. ILs contain special and great properties such as wide range thermal stability, good solvating ability, high ionic conductivity, negligible vapor pressure or non-volatility at room temperature, non-flammability, low toxicity, adjustable solubility, and very low corrosivity14,15.ILs are novel solvents which are “green” and “environmentally friendly” alternative of some traditional volatile organic solvents. ILs are suitable solvent replacement in different organic reactions, electrochemistry (batteries, sensors, solar cells, and separation process), industrial processes (thermal fluids and acid scavenging), spectroscopy, and material science16,17,18. In addition to their applicability in solvent media, they could be utilized as homogenous and/or heterogenous catalysts in many organic and bioorganic transcreations19.Recently designation ILs based on biomolecules and natural compounds (as cations and/or anions) got special research interest due to their special characteristics such a biodegradability (that is related to green chemistry’s important rule), easily preparation techniques, good chemo and/or stereo-selectivity, and accessible natural resources. The amino acid-derived ionic liquids (AAILs), AAILs could play multiple roles as solvents and/or catalysts with high catalytic activity and also as chiral additives20. Polysaccharide- and lignin-based ionic liquids, demonstrated catalytic applications as well as environmental remediations21. Carbohydrate-based ionic liquids, displayed several applications in the fields of catalysis, biomedicine, ecology, biomass, and energy conversion22.Bio-ionic liquids and also catalytic systems based on alanine (ALA) amino acid, represented special roles in various transformations. Yang group in 2008, synthesized new series of ILs ([Cnmim][Ala]) based on alanine anion and 1-alkyl-3-methylimidazolium cation ([Cnmim], n = 2,3,4,5,6), and studied their physicochemical properties such as molecular volume, surface tension, molar enthalpy of vaporization, and thermal expansion coefficient23. Gathergood et al. in 2023, gained some classes of dipeptide ILs with L-alanine fragments and examined their microbial toxicity screening and aerobic biodegradation testing24. Matavos-Aramyan research group in 2019, introduced two novel chiral ionic liquids based on the L-( +)-alanine [which are 1-(4-((1-carboxyethyl)carbamoyl)benzyl)pyridin-1-ium chloride and 1-(4-(((1-carboxyethyl)carbamothioyl)carbamoyl)benzyl)pyridin-1-ium chloride] and examined their antibacterial and antioxidant preparties that demonstrated that they are potent to replace many antibiotic, and potentially, anticancer compounds25.Presence of chromenopyrazole moiety in heterocycles, ultimate notable characteristics that made the compounds applicable in various field of chemistry, science and technology. Choi group in 2018, reported chromenopyrazole-based bipolar blue host materials for highly efficient thermally activated delayed fluorescence organic light-emitting diodes26. In 2023, spirocyclization of chromenopyrazoles yielded the improved inhibitory activity against the oncogenic RNA-binding protein LIN2827. Some chromeno[4,3-d]pyrazolo[3,4-b]pyridin-6(3H)-ones consist high fluorescence quantum yields, that recommended them as luminescence or fluorescence probe28. Bazgir research group in 2010, prepared aqueous-mediated spiro[chromeno[2,3-c]pyrazole-4,3′-indoline]-2′,5(6H)-diones via cyclocondensation reaction of isatins, 1,3-cyclohexadiones, and 3-methyl-1-phenyl-1H-pyrazol-5-ol, in the presence of p-TSA under reflux conditions29. Mukhopadhyay and co-workers in 2017, synthesized spiro[chromeno[2,3-c]pyrazole-4,3′-indolin]-2′,5-diones in the presence of recyclable spinel ZnFe2O4 nanopowder via three-component reaction of substituted isatins, cyclic-1,3-diketones, and 1-phenyl pyrazolone in 80 °C water medium30. Mohammadi Ziarani group in 2018, obtained spiro[chromeno[2,3-c]pyrazole-4,3′-indoline]-2′,5(6H)-diones via cyclocondensation reaction of isatins, 1,3-cyclohexadiones, and pyrazolone in aqueous media using sulfonic acid-functionalized mesoporous silica (SBA-Pr-SO3H) in refluxing water31. Safaei-Ghomi et al. in 2016, reported domino four-component reaction of hydrazines, ethyl acetoacetate, isatins, and cyclic 1,3-diketones in the presence of Fe3O4@SiO2-SO3H or Fe3O4@SiO2-NH2 NPs (as catalyst) in EtOH at 80 °C to get spiro[chromeno[2,3-c]pyrazole-4,3′-indoline]-diones. Fe3O4@SiO2-SO3H NPs signified as better promoter32. Das group in 2015, obtained functionalized tricyclic 4-spiropyrano[2,3-c]pyrazoles via the domino four-component reaction of hydrazines, ethyl acetoacetate, cyclic 1,2-dicarbonlys (such as ninhydrin and isatins), and cyclic 1,3-diketones in 90 °C aqueous medium using dodecylbenzenesulphonic acid (DBSA) as a Brønsted acid-surfactant combined catalyst33. It must be mentioned that reports for the preparation of functionalized tricyclic 4-spiropyrano[2,3-c]pyrazoles via the domino four component reaction of hydrazines, ethyl acetoacetate, cyclic 1,2-dicarbonlys, and cyclic 1,3-diketones are rare32,33.Recently, diverse multi-layered novel magnetized silicated nanostructures get special attention in various fields of science, technology, and catalysis34,35,36,37. Several kinds of silicate materials has bene utilized as linkers and/or supports due to special characteristics such as hydrophilicity (due to their surface silanol groups), biocompatibility, post-functionalization capability, agglomeration avoidance of nano-sized cores, low toxicity, easily surface modification, stability, cost-effectiveness and oxidation preventer of their inner layers38,39.In recent years, several types of magnetized nanohybrids (consist of bio/organic and inorganic parts) get special attention in various fields of science and technology such as nanocarrier for targeted gene delivery into HEK-293 T cells40, removal of toxic pollutants from contaminated water41, Magnetic resonance/Raman imaging42, and catalysts of various transformations43.In continuation of our research field in synthesizing of amino-acid based catalysts and examining their catalytic efficacy in multi-component reactions under green conditions44,45,46,47, herein we prepared a novel magnetized inorganic-bioorganic nanohybrid (nano FeAl2O4-SiO2@[DL-Ala][NO3]) via step-by-step functionalization of spinel FeAl2O4 core by silica and alaninium nitrate ionic liquid ([DL-Ala][NO3]). The alanine-based multi-layered nanostructure characterized by FT-IR, VSM, FESEM, EDAX, TEM, TGA/DSC, XRF, and XRD techniques. It catalytic efficacy examined via domino four-component one-pot reaction of various hydrazine derivatives, ethyl acetoacetate, heterocyclic 1,2-ketones and cyclic 1,3-diketones in refluxing aqueous media to obtain some dihydro-1H-spiro[chromeno[2,3-c]pyrazole-4,2′-indene]-1′,3′,5(6H)-triones and dihydro-1H-spiro[chromeno[2,3-c]pyrazole-4,3′-indoline]-2′,5(6H)-diones (Fig. 1).Figure 1Scheme for synthesis of dihydro-1H-spiro[chromeno[2,3-c]pyrazole-4,2′-indene]-1′,3′,5(6H)-triones and dihydro-1H-spiro[chromeno[2,3-c]pyrazole-4,3′-indoline]-2′,5(6H)-diones.
