Debus-Radziszewski Reaction Research Articles

Rational Synthesis of Functionalized Covalent Organic Frameworks via Four-Component Reaction.

The construction of function-oriented covalent organic frameworks (COFs) remains a challenge as it requires simultaneous consideration of diversified structures, robust linkage, and tailorable functionalities. Herein, we report the rational synthesis of functionalized COFs via a four-component reaction strategy. Through the four-component Debus-Radziszewski reaction, 11 N-substituted imidazole-based COFs with diversified structures were facilely constructed from readily available building blocks. By forming the N-substituted imidazole linkage, these synthesized COFs displayed ultrastability toward strong acids and base. Moreover, the four components reaction allows the rational synthesis of COFs with tailorable functionalities. As an example, the phosphonate-functionalized COF (LZU-530) was rationally constructed for the efficient adsorption of uranium(VI). The uranium(VI) uptake of LZU-530 reaches up to 95 mg·g-1 in 2 M HNO3, which is the highest uptake of the existing organic porous materials under such harsh conditions. Our results highlight the use of multicomponent reaction for the rational synthesis of robust and functionalized COFs toward targeted applications.

Imidazolium-Containing Hybrid Organic-Inorganic Materials for the Conversion of CO2: Unveiling the Key Role of the Ionic Template.

A straightforward synthesis of a series of hybrid organic-inorganic materials (HOIMs) containing imidazolium moieties was achieved. The preparation of the imidazolium acetate precursor was performed in a single-step procedure using the Debus-Radziszewski reaction. The as-synthesized alkoxysilane was employed in combination with tetraethyl orthosilicate to generate an HOIM presenting a high specific surface area. Two different structure-directing agents (SDAs), an anionic (sodium dodecyl sulfate (SDS)) or a cationic (cetyltrimethylammonium bromide) surfactant, were used to investigate the role played by the SDA on the distribution of the imidazolium-based active sites within the silica structure. After the synthesis, the acetate ion was replaced with Cl- and Br- via a simple acid treatment. This procedure favors also the removal of the surfactant, thus releasing the porosity of the solids. The HOIMs synthesized were fully characterized via low-angle X-ray diffraction, N2 physisorption, transmission electron microscopy, 13C and 29Si MAS NMR, combustion chemical analysis, X-ray photoelectron spectroscopy, and CO2 physisorption to assess their physicochemical and structural features, as well as the successful incorporation of imidazolium salts. Their catalytic activity in the conversion of CO2 was tested over different epoxides to produce the corresponding cyclic carbonates. The key role of the SDS (anionic surfactant) as a templating agent was proved. The best material was stable under the selected reaction conditions, reusable over multiple cycles, and active on a series of different epoxides, thus proving its versatility.

Unlocking the potential of aromatase inhibitors: recent advances in drug design, synthesis, docking activity, and in vitro bioactivity evaluations

Breast cancer, a global health concern claiming approximately 685,000 lives in 2020, necessitates continual advancements in therapeutic strategies. Estrogen and aromatase play pivotal roles in hormone-responsive breast cancer, with 80% of patients exhibiting estrogen receptor-positive tumors. Aromatase inhibitors (AIs), notably non-steroidal inhibitors like anastrozole and letrozole, have significantly improved outcomes, yet challenges persist, including side effects. This review focuses on recent developments in AIs, exploring xanthone derivatives, imidazole derivatives, and curcumin derivatives as potential inhibitors of aromatase. Molecular docking studies, employing Auto Dock and other tools, reveal the binding affinities and interactions of these compounds with the aromatase enzyme. Among xanthones, Erythrommone emerges as a potent inhibitor, holding promise for clinical trials. Imidazole derivatives, synthesized through the Debus-Radziszewski reaction, demonstrate anticancer potential, with compounds like 1a exhibiting superior efficacy against MCF7 cells. ADME-Tox analyses indicate promising drug-likeness but reveal potential mutagenic effects and environmental impacts. Curcumin derivatives, particularly 1,5-diaryl-1,4-pentadien-3-ones, present alternatives to address curcumin's bioavailability challenges. A study of 25 compounds (DKC) identifies DKC-10 as a potent inhibitor, outperforming established breast cancer drugs in terms of binding affinity and interactions with aromatase and ERα+ receptors. These findings underscore the importance of exploring diverse chemical structures in developing AIs, paving the way for more effective and well-tolerated therapeutics. The integration of computational techniques, such as molecular docking studies, accelerates drug discovery by predicting interactions at the molecular level. Overall, this comprehensive review provides valuable insights into the evolving landscape of aromatase inhibitors, offering a roadmap for future research and the development of advanced breast cancer therapeutics.

Ionic Conjugated Microporous Polymers for Cycloaddition of Carbon Dioxide to Epoxides

AbstractAlong the development of ionic porous organic polymers, simple and efficient synthetic methods are actively pursued. Herein, the Debus–Radziszewski reaction is applied to synthesize ionic conjugated microporous polymers (iCMPs) in one step. A series of imidazolium‐linked iCMP‐X (X = 1, 2, 3) are developed for CO2 sorption and in situ conversion with epoxide into cyclic carbonates. The as‐synthesized iCMPs are characterized in detail by scanning electron microscope, solid‐state nuclear magnetic resonance, X‐ray photoelectron spectroscopy, X‐ray diffraction analysis, N2/CO2 sorption, and more. Among all synthesized iCMPs, iCMP‐1 possesses the highest specific surface area and in turn the strongest CO2 sorption capacity. Moreover, through a simple anion ion exchange reaction with halide, iCMP‐1 is transformed to iCMP‐1@Cl that embodies significant catalytic capability for converting CO2 into cyclic carbonates.

Multicomponent Synthesis of Imidazole-Linked Fully Conjugated 3D Covalent Organic Framework for Efficient Electrochemical Hydrogen Peroxide Production.

The semiconducting properties and applications of three dimensional (3D) covalent organic frameworks (COFs) are greatly hampered because of their long-ranged non-conjugated skeletons and relatively unstable linkages. Here, a robust imidazole-linked fully conjugated 3D covalent organic framework (BUCT-COF-7) is synthesized through the one-pot multicomponent Debus-Radziszewski reaction of the saddle-shaped aldehyde-substituted cyclooctatetrathiophene, pyrene-4,5,9,10-tetraone, and ammonium acetate. The semiconducting BUCT-COF-7, as a metal-free catalyst, shows excellent two electron oxygen reduction reaction (ORR) activity in alkaline medium with high hydrogen peroxide (H2 O2 ) selectivity of 83.4 %. When the BUCT-COF-7 as cathode catalyst is assembled into the electrolyzer, the devices showed high electrochemical production rate of H2 O2 up to 326.9 mmol g-1 h-1 . The accumulative amount of H2 O2 could totally degrade the dye methylene blue via Fenton reaction for wastewater treatment. This is the first report about intrinsic 3D COFs for efficient electrochemical synthesis of H2 O2 , revealing the promising applications of fully conjugated 3D COFs in the environment-related field.

Recent developments in amino acid-derived imidazole-, imidazolium- and N-heterocyclic carbene-carboxylate complexes

Compounds based on imidazole or imidazolium moieties are excellent building blocks for the preparation of a plethora of ligand precursors. The introduction of chirality in these compounds is relatively easy through the Debus-Radziszewski reaction, in which the chiral pools are natural or non-natural amino acids. Using this synthetic route, enantiopure imidazole-carboxylate, imidazolium-carboxylate, and imidazolium-dicarboxylate ligand precursors can be prepared, from which N-heterocyclic carbenes (NHC) with one or two carboxylate groups can also be obtained. This review is a personal account that summarizes our recent results regarding the use of all these compounds as chiral ligands coordinated to several transition metals (Cu, Zn, Ag and Mo). The structural features of the new synthesized coordination polymers with novel bonding modes will be described, and the bonding capabilities of these ligands rationalized on the basis of theoretical calculations. The efficiency of homochiral imidazolium-dicarboxylate compounds as chiral inductors in asymmetric catalysis will also be discussed. Finally, the antimicrobial and antitumoral activities of imidazolium- and NHC-carboxylate silver complexes and the found chirality-activity and structure–activity relationships will be highlighted.

Multipurpose of Zwitterionic Poly(imidazolium)-Based Hydrogel Coating for Oil/Water Separation with Long-Term Antibiofouling Property

Hydrogel coatings have been applied to separate oil/water mixtures with low oil fouling property. However, most contemporary hydrogels have a short lifespan because of their poor antimicrobial and anti-biofouling ability. Zwitterionic polymeric materials have shown their potential to inhibit microbe (e.g., bacteria) adhesion and can deactivate bacteria by cationic moieties in zwitterion. Herein, we developed a zwitterionic poly(imidazolium) (ZPIM)-based hydrogel coated stainless steel mesh (SSM) with superhydrophilicity and underwater superoleophobicity. The 3D hydrogel network was constructed via cross-linking chitosan with the Debus-Radziszewski reaction, which resulted in the formation of poly(imidazolium) chain. Moreover, PVA and diatomite were also introduced to improve the mechanical property of ZPIM hydrogel coating, resulting in outstanding stability and endurance under harsh conditions. Finally, the ZPIM coated SSM demonstrated high water flux and oil separation efficiency (>99.5 %) as well as superb antibacterial and anti-biofouling activity against both Gram-positive and Gram-negative bacteria. Overall, the study of ZPIM hydrogel coating revealed a new technique for fabricating oil/water separation materials for practical application with low in cost, effective in preparation and excellent bio-fouling resistance.

A Porphyrinic Donor-Acceptor Conjugated Porous Polymer as Highly Efficient Photocatalyst for PET-RAFT Polymerization.

Heterogeneous catalysts offer a highly desirable platform for exploring environmental-benign transformation systems, yet, they typically suffer from significant loss of catalytic efficiency compared with their homogeneous counterparts. Here, the facile synthesis of a porphyrinic conjugated porous polymer incorporated with imidazolium bromide moieties by taking advantage of the Debus-Radziszewski reaction is reported. Owing to the unique donor-acceptor structure, this heterogeneous and metal-free photocatalyst exhibits much improved catalytic activity compared with its small molecular analogs in photoinduced electron transfer reversible addition-fragmentation chain transfer (PET-RAFT) polymerization, producing polymers with narrow distribution (Đ = 1.06-1.18) and high degree of chain-end fidelity. Moreover, the heterogeneous catalyst can be easily separated at the end of polymerization by centrifugation and recycled for five independent PET-RAFT polymerizations without obvious decreases in catalytic efficiency.

Siloxane-Based Main-Chain Poly(ionic liquid)s via a Debus-Radziszewski Reaction.

Herein, we synthesized a series of siloxane-based poly(ionic liquid)s (PILs) with imidazolium-type species in the main chain via the multicomponent Debus–Radziszewski reaction. We employed oligodimethylsiloxane diamine precursors to integrate flexible spacers in the polymer backbone and ultimately succeeded in obtaining main-chain PILs with low glass transition temperatures (Tgs) in the range of −40 to −18 °C. Such PILs were combined with conventional hydrophobic vinylimidazolium-based PILs for the fabrication of porous membranes via interpolyelectrolyte complexation with poly(acrylic acid), which leads to enhanced mechanical performance in the tensile testing measurements. This study will enrich the structure library of main-chain PILs and open up more opportunities for potential industrial applications of porous imidazolium-based membranes.

Trifunctional Metal-Organic Framework Catalyst for CO2 Conversion into Cyclic Carbonates.

Herein, we reported a facile strategy for the preparation of trifunctional ionic metal-organic frameworks (MOFs) incorporating imidazolium cation functionalities. This strategy exploits the Debus-Radziszewski reaction to create the cationic imidazole ring by postsynthetic modification, meanwhile introducing exchangeable counteranions. On the basis of this strategy, MIL-101-IMOH-Br- has been synthesized, which combines Lewis acidic sites, Brønsted acidic sites, and nucleophilic centers to achieve catalysis for the carbon dioxide-epoxide cycloaddition into cyclocarbonate without any cocatalyst and solvent.

Recent Advances on Fabrication of Polymeric Composites Based on Multicomponent Reactions for Bioimaging and Environmental Pollutant Removal.

As the core of polymer chemistry, manufacture of functional polymers is one of research hotspots over the past several decades. Various polymers are developed for diverse applications due to their tunable structures and unique properties. However, traditional step-by-step preparation strategies inevitably involve some problems, such as separation, purification, and time-consuming. The multicomponent reactions (MCRs) are emerging as environmentally benign synthetic strategies to construct multifunctional polymers or composites with pendant groups and designed structures because of their features, such as efficient, fast, green, and atom economy. This mini review summarizes the latest advances about fabrication of multifunctional fluorescent polymers or adsorptive polymeric composites through different MCRs, including Kabachnik-Fields reaction, Biginelli reaction, mercaptoacetic acid locking imine reaction, Debus-Radziszewski reaction, and Mannich reaction. The potential applications of these polymeric composites in biomedical and environmental remediation are also highlighted. It is expected that this mini-review will promote the development preparation and applications of functional polymers through MCRs.

Dehydration of heavy crude oil emulsions using novel imidazolium-based poly ionic liquids

Sea water/ heavy crude oil emulsions are highly stable and cause serious industrial problems. Amphiphilic poly ionic liquids (ILs) as environmentally safe chemicals can be used as highly efficient demulsifiers to for W/O emulsions. In the present work, two imidazolium-based poly ionic liquids (IMPIL-1 and IMPIL-2) were prepared via one pot modified Debus-Radziszewski reaction by the interaction of triethylenetetramine or diethylenetriamine with glyoxal and formaldhyde in aqeous acetic acid solution. The prepared PILs were after that reacted with glycidyl 4-nonylphenyl ether through the epoxy ring opening to produce two amphiphilic PILs. 1HNMR, DLS and drop shape analyzer were utilized to verify their chemical structures and surface properties of the prepared PILs. The surface properties of AIMPIL-1 and AIMPIL-2 and their ability to reduce the IFT of sea water/ crude oil interface recommended their application as demulsfiers for W/O emulsions. Factors affecting the demulsification properties like relative solubility index, Demulsifier dose and separation time were investigated. The results confirmed the high efficiency of AIMPIL-1 and AIMPIL-2 to act as demulsifiers for W/O emulsions with a priority to the less aminated AIMPIL-1 that reached 100% for emulsion compositions (30/70 and 10/90 vol%).

One-pot synthesis of symmetric imidazolium ionic liquids N,N-disubstituted with long alkyl chains.

The Debus–Radziszewski imidazole synthesis was adapted to directly yield long-chain imidazolium ionic liquids. Imidazolium acetate ionic liquids with side-chains up to sixteen carbon atoms were synthesised in excellent yields via an on-water, one-pot reaction. The imidazolium acetate ILs acted as surfactants when dissolved in various solvents. The imidazolium acetate ionic liquids were also derivatised via an acid metathesis to the chloride, nitrate, and hydrogen oxalate derivatives. The thermal behaviour of all the ionic liquids was determined via thermogravimetric and calorimetric analysis.

Syntheses of Pyrazine-, Quinoxaline-, and Imidazole-Fused Pyrroline Nitroxides

A synthesis of a new diamagnetic synthon, 1-methoxy-2,2,5,5-tetramethylpyrrolidine-3,4-dione, was developed. Condensation of this compound with aliphatic or aromatic 1,2-diamines followed by deprotection yielded pyrroline nitroxide-fused pyrazines, pteridines, or quinoxalines, demonstrated on 7 examples in 15–39% overall yield over 2 or 3 steps. Reaction of the diamagnetic 1,2-diketone with an aldehyde and ammonium acetate produced a pyrrolo[3,4-d]imidazole scaffold in the Debus–Radziszewski reaction.

Phenanthro[9,10-d]imidazole with thiophene rings toward OLEDs application

A series of phenanthro [9,10-d]imidazole derivatives with thiophene units were synthesized using the Debus-Radziszewski reaction. A study of the optical, electrochemical and thermal properties of the new compounds was conducted. All derivatives were found to be thermally stable, with high melting temperatures (250–267 °C) and with the beginning of decomposition starting above 350 °C. They underwent the multistage electrochemical reduction. All phenanthro [9,10-d]imidazole derivatives were luminescent in solution and in solid state. In solution they emitted radiation with maximum emission band located at 414–461 nm with photoluminescence quantum yields in the range of 56%–64% in chloroform. As films they emitted blue light with ΦPL ranging from 12 to 23%. The possibility of applying one of the synthesized compound in optoelectronics devices was studied as well. The devices showed intense electroluminescence which can be further enhanced by increasing the content of 2-(2,2′-bithiophen-5-yl)-1-phenyl-1H-phenanthro [9,10-d]-imidazole in the active layer.

The multicomponent Debus–Radziszewski reaction in macromolecular chemistry

The well-known Debus–Radziszewski reaction is over one century old. However, this reaction has only been considered very recently as a new tool to design original imidazole and imidazolium-containing polymers by direct formation of the imidazole ring during the polymerization process. This article reports recent advances concerning the use of this newly emerging reaction in macromolecular chemistry.

In Situ Synthesis of Imidazolium-Crosslinked Ionogels via Debus-Radziszewski Reaction Based on PAMAM Dendrimers in Imidazolium Ionic liquid.

This study reports a remarkably facile method to synthesize novel ionogels with imidazolium cycle crosslinks based on polyamidoamine (PAMAM) dendrimers via one-pot, modified Debus-Radziszewski reaction in ionic liquid 1-ethyl-3-methylimidazolium acetate ([EMIM][OAc]). High room temperature ionic conductivity (up to 6.8 mS cm-1 ) is achieved, and more remarkably, it can still exceed 1 mS cm-1 when the dendrimer content reached 70% because PAMAM dendrimers are completely amorphous with many cavities and the newly formed imidazolium crosslinks contains ions. The elastic modulus of these ionogels can exceed 106 Pa due to the newly-formed rigid imidazolium crosslinks. Crucially, these ionogels are robust gels even at temperatures up to 160 °C. Such novel ionogels with high ionic conductivity, tunable modulus, and flexibility are desirable for use in high-temperature flexible electrochemical devices.

Click-based porous cationic polymers for enhanced carbon dioxide capture

Imidazolium-based porous cationic polymers were synthesized using an innovative and facile approach, which takes advantage of the Debus–Radziszewski reaction to obtain meso-/microporous polymers following click-chemistry principles.

ChemInform Abstract: Halogen‐Free Synthesis of Symmetrical 1,3‐Dialkylimidazolium Ionic Liquids Using Non‐Enolisable Starting Materials.

Imidazolium ionic liquids were synthesized from readily available molecules: aldehydes, 1,2-carbonyl components, alkyl amines and acids in a halogen-free procedure. Since the use of enolisable carbonyl functions is not compatible with the modified Debus–Radziszewski reaction, symmetrical 1,3-dialkylimidazolium ionic liquids were made. The use of strong acids, like sulfuric acid, leads to protonation of the amine, low yields and side products that are difficult to remove. Changing the acid in the synthesis to acetic acid greatly improved the isolated yield and produced pure imidazolium acetate ionic liquids. From these imidazolium acetate compounds, many other ionic liquids could be prepared using different metathesis strategies. These strategies were dependent on the acidity of the conjugate acid of the anion, the acid volatility and the hydrophilicity of the used reagents and resulting ionic liquid. The following anions were introduced: bis(trifluoromethylsulfonyl)imide ([Tf2N]−), p-toluenesulfonate (tosylate, [TsO]−), bis(2-ethylhexyl)phosphate ([DEHP]−) and nitrate ([NO3]−). The impact of the different anions on the properties of the ionic liquids was investigated.

Cis and trans Isomers distinguished by imidazole N-alkylation after Debus-Radziszewski reaction starting from 2,7-di-tert-butyl-pyrene-4,5,9,10-tetraone

We report the design and synthesis of three new imidazo[5,4-f]2,7-di-tert-butyl-pyrene-imidazol derivatives prepared from 2,7-di-tert-butylpyrene-4,5,9,10-tetraone and respective aromatic aldehyde through Debus-Radziszewski reaction. It is noted that three pairs of cis and trans isomers (1–6) can be separated after double imidazole N-alkylation for the central fused imidazole/pyrene/imidazole core, because of their distinguishable molecular polarity and improved solubility. Successful separation of every cis and trans isomeric pair can be verified by the single-crystal structural and spectral proofs. To the best of our knowledge, the current study is the first structural and spectral investigation on the imidazole N-alkylation of imidazole/pyrene/imidazole based compounds after successful separation of cis and trans isomers.