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Stable palladium (II) complexes, incorporating a double (N-benzoylthiourea) arrangement bonded to a complex heterocyclic scaffold, are used as precursors of catalytic species able to promote Suzuki–Miyaura, Mizoroki–Heck, Hiyama, Buchwald–Hartwig, Hirao and Sonogashira–Hagihara cross-coupling transformations in water. These sustainable processes are chemoselective and very versatile. The nanoparticles responsible for these catalytic reactions were analyzed and studied. Their usefulness is demonstrated after several tests and analyses. The heterogeneous character of this species in water was also confirmed.

Zeolitic imidazolate framework-67 (ZIF-67) functionalized with graphene quantum dots was prepared and utilized for the reduction of Au (III) and stabilization of Au nanoparticles. This newly prepared ZIF-67/GQD@Au was characterized with different techniques and employed as a capable heterogeneous catalyst for reduction of aromatic nitro compounds and A1-coupling reaction of alkynes, amines, and aldehydes in water solvent. Experiments indicate that this catalyst is able to reduce nitroarenes in short reaction times (10–20 min) in water at room temperature and corresponding amines were obtained in excellent yields (90–100%). Also, reactions of structurally different alkynes, amines, and aldehydes in the presence of this catalyst proceed effectively at 60°C and desired propargylic amine achieved in good to very good yields (76–88%) in water during 1 day. This catalyst displayed excellent stability and recyclability in both reactions and recycled for six runs with a small decrease in the activity.

Herein, core–shell magnetic nanoparticles are modified with imidazolium-tagged phosphine and propylene glycol moieties and used for the stabilization of bimetallic AuCu nanoparticles. The structure and morphology of the prepared material are identified with SEM, TEM, XRD, XPS, atomic absorption spectroscopy, Fourier translation infrared spectroscopy, and a vibrating sample magnetometer. This hydrophilic magnetic bimetallic catalyst is applied in the reduction of toxic nitroarenes and reductive degradation of hazardous organic dyes such as methyl orange (MO), methyl red (MR), and rhodamine B (RhB), as well as in the degradation of tetracycline (TC). This magnetic AuCu catalyst indicated superior activity in all three mentioned reactions in comparison with its single metal Au and Cu analogs. This catalyst is recycled for 17 consecutive runs in the reduction of 4-nitrophenol to 4-aminophenol without a significant decrease in catalytic activity and recycled catalyst is characterized.

Multilayer graphene (MLG), obtained by mild sonication of graphite in NMP, was functionalised via 1,3-dipolar cycloaddition with azomethine ylides generated by thermal 1,2-prototropy from various imino esters. The microwave-assisted functionalisation took place in five hours at 100 °C. The resulting MLG, containing substituted proline-based amine functional groups, was characterized using XPS and showed a nitrogen loading three times that obtained for the same transformation performed for five days using convection-assisted heating. The preparation of the imino ester containing a bipyridine unit at the arylidene position allowed for the preparation of the corresponding functionalised MLG, which incorporated the ruthenium atom to achieve a heterogeneous MLG-Ru complex. This supported complex was tested, as a proof of concept, as a photocatalyst of the aerobic oxidative hydroxylation of 4-methoxyphenylboronic acid.

Se conoce que los complejos quirales de Ag(I), Cu(I) o Cu(II) y Zn(II) catalizan eficazmente la cicloadición entre iluros de azometino generados a partir de iminoésteres y alquenos electrofílicos dando lugar a derivados heterocíclicos con elevadas enantioselectividades. Esta reacción suele funcionar con cantidades subestequiométricas tanto de base como de complejo quiral que actúa como ácido de Lewis, siendo impresionante el control de la reacción sobre los tres o los cuatro nuevos centros estereogénicos formados. De acuerdo con la experiencia previa del grupo de investigación en esta reacción 1,3-dipolar enantioselectiva, durante la elaboración de la siguiente memoria se estudiará la enantioselectividad de la cicloadición 1,3-dipolar de iluros de azometino y derivados alquénicos de la sacarina, en presencia de un ligando quiral constituido por diversos metales como Ag o Cu(II). Los derivados de isotiazol han demostrado tener una interesante actividad biológica, pues resultan ser precursores de sustancias que inhiben la acción de virus como el Sars-Cov2.

Herein, silica-core shell magnetic nanoparticles were functionalized with imidazolium-based ionic liquid and 3-amino-1,2-propanediol, and the resulting hydrophilic media was used to stabilize bimetallic CoCu species. The structure of this new composite, Fe3O4@ILD-CoCu, was identified and analyzed by various techniques including TEM, XRD, XPS, VSM, FT-IR, EDX, and SEM Mapping. In the following, its catalytic performance was investigated in the reduction of nitrophenol compounds including 4-nitrophenol (4-NP), 3-nitrophenol (3-NP), and 2-nitrophenol (2-NP), decolorization of organic dyes such as methyl orange (MO), methyl red (MR), and rhodamine B (Rh B) and degradation of tetracycline and the results showed that the mentioned compounds participated properly in the reduction and degradation reactions. The research results showed that bimetallic cobalt-copper catalyst performs much better than monometallic cobalt and copper catalysts. The recyclability of the desired magnetic catalyst was also investigated and showed 14 runs of recyclability without a significant reduction in catalytic activity.

The asymmetric catalytic synthesis of 1,2-diamines has received considerable interest, especially in the last ten years, due to their presence in biologically active compounds and their applications for the development of synthetic building blocks, chiral ligands and organocatalysts. Synthetic strategies based on C–N bond-forming reactions involve mainly (a) ring opening of aziridines and azabenzonorbornadienes, (b) hydroamination of allylic amines, (c) hydroamination of enamines and (d) diamination of olefins. In the case of C–C bond-forming reactions are included (a) the aza-Mannich reaction of imino esters, imino nitriles, azlactones, isocyano acetates, and isothiocyanates with imines, (b) the aza-Henry reaction of nitroalkanes with imines, (c) imine–imine coupling reactions, and (d) reductive coupling of enamines with imines, and (e) [3+2] cycloaddition with imines. C–H bond forming reactions include hydrogenation of C[double bond, length as m-dash]N bonds and C–H amination reactions. Other catalytic methods include desymmetrization reactions of meso-diamines.

A novel magnetic nanocomposite modified with a new branched polymer containing nitrogen-rich ligand moieties was synthesized and used to stabilize Pd nanoparticles. The resulting catalyst was characterized by Fourier transform infrared spectroscopy, transmission electron microscopy, scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, vibrating sample magnetometry, thermogravimetric analysis and energy-dispersive X-ray. The synthesized catalyst has been applied as an efficient catalyst in the reduction of nitro compounds to corresponding amines and reductive degradation of organic dyes such as methyl orange and methyl red. The catalyst showed high stability and reusability for 10 runs without significant loss in catalytic activity.

In this work, a convenient approach has been applied to discover the potential valorization of biomass waste such as orange peel in which PdCu-based nanostructured systems were synthesized via a one-step in-situ dry-milling approach to obtain the benign bimetallic catalysts with different palladium(Pd) and Copper(Cu) loadings on the orange peel support (Pd1%Cu1%, Pd0.3%Cu0.7%, Pd0.5%Cu0.5%, Pd0.5%Cu1%). Catalytic applications of these new composites were investigated in the Sonogashira-Hagihara coupling reaction as well as the Sonogashira–click reaction sequence to the preparation of substituted 4-aryl-1,2,3-triazoles and reduction of nitroaromatics under mild reaction conditions. Catalytic tests with the four activated carbons catalysts showed that the C@Pd1%Cu1% catalyst was the most active in the Sonogashira-Hagihara coupling reaction compared to the other catalysts. Also, the C@Pd0.5%Cu0.5% catalyst showed the highest catalytic activity in the reduction of 1-chloro-4-nitrobenzene and 4-nitrophenol in comparison with other prepared carbon catalysts.

The stereoselective synthesis of vicinal amino alcohols derivatives from 1-substituted cyclopropanols and chiral N-tert-butanesulfinyl imines is described. Cyclopropanols are easily prepared from carboxylic esters upon reaction with ethylmagnesium bromide in the presence of titanium tetraisopropoxide and undergo carbon–carbon bond cleavage by means of diethylzinc to produce, upon base deprotonation, enolized zinc homoenolates, which react with chiral sulfinyl imines in a highly regio- and stereoselective manner.

Single-walled carbon nanotubes (SWCNTs) were functionalized by treatment with imino esters through 1,3-dipolar cycloaddition activated by thermal 1,2-prototropy. The reaction was optimized and analyzed by using various heating methods. The functionalization afforded pyrrolidino-functionalized nanotubes that were characterized by using several techniques. The ester group was then transformed into the corresponding SWCNT–iridium carboxylate and, as a proof of concept, the product was tested as a catalyst in the hydrogen-transfer reaction of acetophenone to yield 1-phenylethanol.

Designing efficient hydrophilic catalysts for applying in aqueous media is still a great sustainable processes challenge. In this research, glycerol as a non-toxic and biodegradable chemical was used for preparation of water dispersible magnetic nanoparticles which was applied for stabilization of Pd NPs. Resulting composite (Fe3O4@SiO2-T-G@Pd) was characterized using multiple techniques including FTIR, SEM mapping, TEM, XRD, VSM, and TGA. Hydrophilic property of the Fe3O4@SiO2-T-G@Pd was proved by experiments. This magnetic palladium catalyst showed high catalytic performance in the conversion of nitro compounds to corresponding amines as well as in C-C coupling reactions in aqueous media with high efficiency and selectivity. Using this catalyst and NaBH4 as reducing agent, structurally different nitroarenes were reduced to corresponding amines with very good to excellent yields in aqueous media at room temperature. Furthermore, typical Suzuki-Miyaura coupling reaction of 4-bromoanisole with phenylboronic acid was proceeded very well in aqueous media at 60°C. The magnetically water dispersible catalyst was recycled and reused several cycles in the reduction of nitrobenzene without significant loss in its activity and stability such as confirmed TEM, SEM and XPS analyses.

A magnetic nanocomposite comprising imidazolium ionic liquid and glucosamine is successfully synthesized and used for stabilization of Pd nanoparticles. This new material, Fe3O4@SiO2@IL/GA-Pd, is fully characterized and applied as a catalyst in the reduction of nitroaromatic compounds to desired amines at room temperature. Also, the reductive degradation of organic dyes such as methylene blue (MB), methyl orange (MO), and rhodamine B (RhB) is studied and compared with another previous publications. The survey of the stabilization of the palladium catalytic entities is described demonstrating the separation ability and recycling of them. In addition, TEM, XRD, and VSM analyses of the recycled catalyst confirmed its stability.

La popularidad de los derivados de maleimida ha aumentado constantemente a lo largo de los años, particularmente en los campos de la biotecnología y la química bioorgánica. Esto se puede atribuir a varios factores importantes que destacan sobre las maleimidas, tanto en términos de velocidad, como de reacción, selectividad y rendimiento, así como su buena estabilidad frente al aire, el agua o el calor. Además, varias maleimidas funcionalizadas ahora están disponibles comercialmente o son fácilmente accesibles en unos pocos pasos sintéticos a bajo costo y a través de estrategias escalables y de alto rendimiento. En el presente trabajo se estudiará la posibilidad de sintetizar una maleimida que posteriormente pueda ser útil a la hora de realizar adiciones Michael, consiguiendo de esta manera derivados de aminoácidos que puedan ser de utilidad.

En esta memoria se ha llevado a cabo la síntesis de diferentes maleimidas quirales derivadas de aminoácidos, además de sus derivados ésteres metílicos para su posterior evaluación en reacciones de cicloadición 1,3-dipolares multicomponentes. Se estudió del alcance sintético de este proceso con modificaciones en la estructura empleando diferentes aminas, aldehídos y maleimidas con el fin de evaluar la diastereoselectividad demostrando, además, la amplia variabilidad estructural en la síntesis de estos compuestos espirocíclicos, tanto en el dipolo como en el dipolarófilo. Con el objetivo de obtener de forma diastereoselectiva nuevas familias de espiropirrolidinas racémicas, se evaluó el empleo de otros dipolarófilos. También fue posible, a partir de dipolos que contenían maleimidas quirales en su estructura, la síntesis diastereoselectiva en su versión enantiopura obteniendo espiropirrolidinas con relaciones diastereoméricas moderadas.

In recent years, the excellent pore volume, huge specific surface area, and easy functionalizable zeolitic imidazolate frameworks (ZIFs), as new type of porous materials, attracted the attention of scientists. In this work, the new Co-based trimetallic Cu-Ni@ZIF-67 was synthesized using embedded the Cu-Ni precursor in ZIF-67. The structure, morphology and properties of Cu-Ni@ZIF-67 was characterized by the various analysis. The catalytic performance of Cu-Ni@ZIF-67 was investigated for tetracycline (TC) degradation and nitroarenes reduction at room temperature. The resultant catalyst was demonstrated excellent TC degradation efficiency by persulfate (PS) activation in the water during 30 min, and Cu-Ni@ZIF-67 was displayed superior catalytic activity for nitroarenes reduction in the presence of NaBH4. Comparing catalytic activity of Cu-Ni@ZIF-67 with Cu/ZIF-67, Ni/ZIF-67, Cu-Ni and ZIF-67 indicated higher activity of Cu-Ni@ZIF-67. Moreover, the recyclability and stability of this catalyst were surveyed.

In this study, bimetallic RuCu supported on l-cysteine functionalized ionic liquid modified magnetic nanoparticles (Fe3O4@IL-Cys-RuCu) was successfully synthesized and characterized. This bimetallic nanocatalyst showed excellent activity in the reduction of 2,3, and 4-nitrophenol isomers and organic dyes as well as catalytic degradation of tetracycline (TC) at room temperature in water. Using this catalyst, complete reduction of nitrophenols was achieved within 9–16 min and degradation of organic dyes and tetracycline were accomplished within 7–4 and 30 min, respectively. The superior activity of bimetallic RuCu compared to similar Ru and Cu catalysts was proved and results indicated that the based on type of reaction, bimetallic catalyst was 2–33 times more efficient than the corresponding monometallic catalysts. This catalyst was recovered and recycled up to 14 times without decreasing in the catalytic activity and stability of the reused catalyst was confirmed by TEM, XRD and XPS.

A novel mixed-linker of iron-based metal–organic frameworks named Fe(INA)(H2N-BDC) has been directly synthesized by mixing 2-amino-1,4-benzenedicarboxylic acid (NH2-BDC) and isonicotinic acid (INA) using hydrothermal method. Its characterization was fully performed by a number of methods such as FT-IR, PXRD, XPS, FESEM, TEM, TGA, ICP and BET and used as a multifunctional bio-photocatalyst for the preparation of 2,4,6-triarylpyridines (TAPs) via tandem photo-oxidation condensation reactions starting from alcohols under sunlight irradiation and air atmosphere in ethanol. Mixed-linker Fe-MOF showed enhanced catalytic activity compared with its analogues with one single ligand, which indicates the synergistic effect of two linkers and Fe-O clusters in Fe(INA)(H2N-BDC) as a photocatalyst with lower band gap. This observation confirmed by an important reduction in the band gap energy and a rise in the characteristic emission of mixed-linker Fe-MOF compared with Fe-MIL-101-NH2 according to the DRS analysis and fluorescence spectrophotometry, respectively. EPR studies clearly indicated that Fe(INA)(H2N-BDC) produces 1O2 and O2•- as active oxygen units under sunlight illumination. Moreover, amine groups in NH2-BDC provide basic functional groups, which in cooperation with acidic sites (Fe in the metal nodes) promote the condensation of the in-situ formed aldehydes with acetophenone and ammonium acetate. Using sunlight irradiation as an energy-saving source, air as a safe oxidant, good yields, reusability of the photocatalyst and any requirement of additives make the present method as an environmentally-friendly method for the preparation of these important scaffolds. This is the first report of the synthesis of TAPs starting from alcohols catalyzed by MOFs.

The N-tert-butanesulfinylimine group behaves as a suitable electron-withdrawing group in 1-azadienes, allowing the diastereoselective synthesis of densely substituted pyrrolidines by 1,3-dipolar cycloadditions (1,3-DCs) with azomethylene ylides. The use of Ag2CO3 as catalyst has allowed one to obtain a wide variety of proline derivatives with high regio- and diastereoselectivities. Subsequent efficient transformations provide valuable proline derivatives, some of which can be used as organocatalysts. The influence of the N-tert-butanesulfinyl group on the diastereoselectivity was studied by computational methods.

Enantioconvergent catalysis has expanded asymmetric synthesis to new methodologies able to convert racemic compounds into a single enantiomer. This review covers recent advances in transition-metal-catalyzed transformations, such as radical-based cross-coupling of racemic alkyl electrophiles with nucleophiles or racemic alkylmetals with electrophiles and reductive cross-coupling of two electrophiles mainly under Ni/bis(oxazoline) catalysis. C–H functionalization of racemic electrophiles or nucleophiles can be performed in an enantioconvergent manner. Hydroalkylation of alkenes, allenes, and acetylenes is an alternative to cross-coupling reactions. Hydrogen autotransfer has been applied to amination of racemic alcohols and C–C bond forming reactions (Guerbet reaction). Other metal-catalyzed reactions involve addition of racemic allylic systems to carbonyl compounds, propargylation of alcohols and phenols, amination of racemic 3-bromooxindoles, allenylation of carbonyl compounds with racemic allenolates or propargyl bromides, and hydroxylation of racemic 1,3-dicarbonyl compounds.

The highly enantioselective organocatalytic synthesis of spirocyclic compounds by Diels-Alder reactions via trienamine using cyclic 2,5-dienones as bisvinylogous precursors and different nitroalkenes as dienophiles is described. The use of cinchonidine-based primary amine as catalyst and benzoic acid as co-catalyst has allowed the construction of a wide variety of spiro compounds containing three stereogenic centres in good yields and excellent diastereo- and enantioselectivities. Additionally, other dienophiles have been evaluated exhibiting different behaviour depending on the electron withdrawing group nature. Subsequent transformations have yielded complex structures with up to five stereocentres. The plausible reaction mechanism has been investigated by computational methods.

Synergistic effects in bimetallic catalysts produce a catalyst with superior activity than a monometallic component. In this work, a novel magnetic crosslinked copoly(ionic liquid) nanohydrogel was synthesized and employed for the stabilization of AuCo bimetallic nanoparticles (Fe3O4@PolyIL-AuCo). This material was characterized using different instrumental techniques such as FT-IR, TGA, XPS, VSM, solid-state UV–Vis, SEM mapping, and TEM. Results indicated a narrow size distribution of nanoparticles and high water dispersibility of Fe3O4@PolyIL-AuCo. Using this catalyst, a series of nitroarenes were reduced to the corresponding amines in aqueous media. In addition, organic dyes were efficiently degraded by this catalyst. Different experiments dealing with the same transformation confirmed that Fe3O4@PolyIL-AuCo exhibited higher catalytic activity than the similar monometallic Au and Co catalysts. This catalyst was recycled for at least 11 consecutive runs with very small deactivation, and TEM, VSM, and XPS confirmed the stability of the reused catalyst.

To overcome numerous health disorders, heterocyclic structures of synthetic or natural origin are utilized, and notably, the emergence of various side effects of existing drugs used for treatment or the resistance of disease-causing microorganisms renders drugs ineffective. Therefore, the discovery of potential therapeutic agents that utilize different modes of action is of utmost significance to circumvent these constraints. Pyrrolidines, pyrrolidine-alkaloids, and pyrrolidine-based hybrid molecules are present in many natural products and pharmacologically important agents. Their key roles in pharmacotherapy make them a versatile scaffold for designing and developing novel biologically active compounds and drug candidates. This review aims to provide an overview of recent advancements (especially during 2015–2023) in the exploration of pyrrolidine derivatives, emphasizing their significance as fundamental components of the skeletal structure. In contrast to previous reviews that have predominantly focused on a singular biological activity associated with these molecules, this review consolidates findings from various investigations encompassing a wide range of important activities (antimicrobial, antiviral, anticancer, anti-inflammatory, anticonvulsant, cholinesterase inhibition, and carbonic anhydrase inhibition) exhibited by pyrrolidine derivatives. This study is also anticipated to serve as a valuable resource for drug research and development endeavors, offering significant insights and guidance.

A sunlight-induced tandem air oxidation-condensation of alcohols with ortho-substituted anilines or malononitrile for the efficient synthesis of benz-imidazoles/-oxazoles/-thiazoles, or benzylidene malononitrile catalyzed by Co-isatin-Schiff-base-MIL-101(Fe) as a heterogeneous multifunctional bio-photocatalyst is reported. In these reactions, Co-isatin-Schiff-base-MIL-101(Fe) acts both as a photocatalyst, and a Lewis acid to catalyze the reaction of the in-situ formed aldehydes with o-substituted anilines or malononitrile. A significant decrease in the band gap energy and an increase in the characteristic emission of MIL-101(Fe) after functionalization with cobalt Schiff-base according to the DRS analysis and fluorescence spectrophotometry, respectively, indicate that the photocatalytic effectiveness of the catalyst is associated primarily to the synergetic influence of Fe–O cluster and Co-Schiff-base. EPR results obviously pointed out that Co-isatin-Schiff-base-MIL-101(Fe) is capable of creating 1O2 and O2⋅− as active oxygen species under visible light irradiation. Using an inexpensive catalyst, sunlight irradiation, air as a cost-effective and abundant oxidant, and a low amount of the catalyst with recoverability and durability in ethanol as a green solvent, make this methodology as an environmentally friendly process with energy-saving organic synthetic strategies. Furthermore, Co-isatin-Schiff-base-MIL-101(Fe) displays excellent photocatalytic antibacterial activity under sunlight irradiation against E. coli, S. aureus and S. pyogenes. Based on our knowledge, this is the first report of using a bio-photocatalyst for the synthesis of the target molecules.

Two supported noble metal species, gold and palladium anchored on an ionic liquid-modified Fe-based metal–organic framework (MOF), were successfully synthesized and characterized by FT-IR, XRD, TEM, XPS, SEM, EDX, and elemental mapping. The ionic liquid post-modified MOF was used for anchoring Au or Pd at ppm levels, and the resulting materials were employed as catalysts in the reduction of nitrophenol isomers, dyes, and Sonogashira–Hagihara reactions. Using the Au@Fe-MOF-IL catalyst, reduction of nitrophenol isomers, as well as the reductive degradation of dyes, e.g., methylene blue (MB), methyl orange (MO), and methyl red (MR) were performed efficiently in water. On the other hand, Pd@Fe-MOF-IL was used as an effective catalyst in the Sonogashira–Hagihara coupling reaction of aryl iodides and bromides using very low amounts of Pd. These catalysts were recycled and reused for several runs without deteriorating remarkably in catalytic performance.

The pseudo-multicomponent reaction between propargyl amine, an aldehyde and an electron-deficient alkene is described. The C–H activation takes place thermally and allows the obtaining of cycloadducts in very good yields with high diastereoselectivities. The relative configuration is determined by X-ray diffraction analysis of the chiral molecule, obtained as a single diastereoisomer, using a chiral maleimide. A brief study of the stability of the possible ylides involved in the process is also mentioned, confirming the high diastereoselectivity observed. The high functional group density of these cycloadducts permits the synthesis of complex heterocycles. After allylation or propargylation of the pyrrolidine nitrogen atom, RCM-DA cycloaddition or cyclotrimerization with an alkyne is studied, respectively. In this last example, the resulting tetracyclic structures are of potential interest as drugs for the treatment of cystic fibrosis.