Multicomponent Domino Reaction Research Articles

Light-Initiated Four-Step Domino-Multicomponent Synthesis of Functionalized Alkylidenecyclobutanes.

A four-step domino-multicomponent reaction (domino-MCR) is described for the synthesis of functionalized E-alkylidenecyclobutanes from 4-hydroxy-2-methylcyclopent-2-enone derivatives and three other simple reagents. The domino-MCR is accomplished in a single protocol, comprising a tandem photochemical [2 + 2]-cycloaddition/Norrish-I/γ-H transfer reaction followed by an acetal protection and an allylic substitution reaction. In parallel, a consecutive process has been established with distinct photochemical and nonradiative sequences. An intramolecular version of these reactions provides access to complex fused-bicyclic alkylidenecyclobutanes.

A facile and green procedure in preparing dibenzo-chromeno-phenazine-diones using an effectual and recyclable Brønsted acidic ionic liquid

First, a Brønsted acid ionic liquid (BAIL) in the role of a double acid-base called 1,3-n-propyl-bipyridinium bisulfonic acid-ditrifluoroacetate (PBPBSDT) was produced, and its skeleton was determined via TGA, mass, 13C NMR, 19F NMR, 1H NMR and FT-IR data. Further, it was successfully applied in the preparation of dibenzo-chromeno-phenazine-dione derivatives (1a-12a, 9–15 min, 90–98%) via one-pot multicomponent domino reaction among 2 mmol 2-hydroxynaphthalene-1,4-dione, 1 mmol benzene-1,2-diamine, and 1 mmol aldehydes under optimal conditions (5 mol% of PBPBSDT, solvent-free, 60 °C). The proper reproducibility of the PBPBSDT homogeneous catalyst (5 times), solvent-free medium, reasonable TON (Turnover Number) and TOF (Turnover Frequency) numbers, the non-metallic framework of the catalyst, and the formation of C-N, C = N, C-C, C = C, C-O bonds in a single operation are the distinct advantages of this protocol.

An Acid-Mediated Multicomponent Domino Reaction for the Synthesis of N-Substituted Isoindolinones

AbstractA one-pot multicomponent reaction of 2-carboxybenzaldehyde, nitriles/anilines and a nucleophile (N,N-disubstituted anilines) for the synthesis of a range of functionalized N-substituted isoindolinone derivatives is described. This metal-free intramolecular cyclization reaction furnishes the desired products in good to excellent yields. The process is environmentally friendly and offers a sustainable method for synthesizing a diverse library of N-substituted isoindolinone derivatives under acidic conditions. This cascade reaction triggers the formation of a C–C and two C–N bonds involving carbonyl and carboxyl groups in the presence of nitriles/anilines. Additionally, in the absence of a nitrogen source, 3-substituted isobenzofuran-1(3H)-ones are synthesized.

Heteropolyaromatic Covalent Organic Frameworks via One-Pot Multicomponent Reactions.

Multicomponent reactions (MCRs) offer a platform to create different chemical structures and linkages for highly stable covalent organic frameworks (COFs). As an illustrative example, the multicomponent Povarov reaction generates 2,4-phenylquinoline from aldehydes and amines in the presence of electron-rich alkenes. In this study, we introduce a new domino reaction to generate unprecedented 2,3-phenylquinoline COFs in the presence of epoxystyrene. This work thus presents, for the first time, structural isomeric COFs produced by multicomponent domino and Povarov reactions. Furthermore, 2,3-phenylquinolines can undergo a Scholl reaction to form extended aromatic linkages. With this approach, we synthesize two thermally and chemically stable MCR-COFs and two heteropolyaromatic COFs using both domino and in situ domino and Scholl reactions. The structure and properties of these COFs are compared with the corresponding 2,4-phenylquinoline-linked COF and imine-COF, and their activity toward benzene and cyclohexane sorption and separation is investigated. The position of the pendant phenyl groups within the COF pore plays a crucial role in facilitating the industrially important sorption and separation of benzene over cyclohexane. This study opens a new avenue to construct heteropolyaromatic COFs via MCR reactions.

Electrochemical assembly of isoxazoles via a four-component domino reaction.

Multicomponent domino reactions via electrochemical annulations have emerged as a robust strategy for the rapid assembly of heterocyclics. Herein, an electrochemical annulation via a [1 + 2 + 1 + 1] four-component domino reaction was accomplished in a user-friendly undivided cell setup to assemble valuable five-membered isoxazole motifs. Our approach is characterized by a high level functional group tolerance and operational simplicity, avoiding the tedious and time-consuming preparation of pre-functionalized substrates. Detailed mechanistic studies were conducted including isotopic labeling, kinetic studies, cyclic voltammetry (CV) analysis, and intermediate characterization, providing support for a radical pathway.

Multicomponent Domino Reaction for Concise Access to 2-Amino-Substituted 1,3,4 Oxadiazoles via Smiles Rearrangement.

A multicomponent domino reaction has been developed for the preparation of N-substituted 2-amino-1,3,4-oxadiazoles directly from various hydrazides (32 examples). The formation of 2-amino-1,3,4-oxadiazole involves the Smiles rearrangement of thiazolidinone, which results in the formation of carbodiimide intermediate that concomitantly undergoes amide-imidic acid tautomerism followed by cyclization. The protocol developed has wide applicability and provides the desired 2-amino-1,3,4-oxadiazole in excellent yields. The GSD studies of NMR spectra of aliphatic substrates (4di, 4dh) revealed the formation of three products, whereas, in the case of allylic and benzylic substrates, thiazolidinones were obtained as the sole products. Furthermore, to elucidate the plausible mechanism, DFT studies were performed affirming carbodiimide as the crucial intermediate for the interconversion of thiazolidinone to oxadiazole.

Brønsted acid catalyzed mechanochemical domino multicomponent reactions by employing liquid assisted grindstone chemistry

Here, we have demonstrated a metal-free energy-efficient mechanochemical approach for expedient access to a diverse set of 2-amino-3-cyano-aryl/heteroaryl-4H-chromenes, tetrahydrospiro[chromene-3,4′-indoline], 2,2′-aryl/heteroarylmethylene-bis(3-hydroxy-5,5-dimethylcyclohex-2-enone) as well as tetrahydro-1H-xanthen-1-one by employing the reactivity of 5,5-dimethylcyclohexane-1,3-dione/cyclohexane-1,3-dione with TsOH⋅H2O as Brønsted acid catalyst under water-assisted grinding conditions at ambient temperature. The ability to accomplish multiple C–C, C=C, C–O, and C–N bonds from readily available starting materials via a domino multicomponent strategy in the absence of metal-catalyst as well as volatile organic solvents with an immediate reduction in the cost of the transformation without necessitates complex operational procedures, features the significant highlights of this approach. The excellent yield of the products, broad functional group tolerances, easy set-up, column-free, scalable synthesis with ultralow catalyst loading, short reaction time, waste-free, ligand-free, and toxic-free, are other notable advantages of this approach. The greenness and sustainability of the protocol were also established by demonstrating several green metrics parameters.

Immobilized Cu(0) nanoparticles on montmorillonite-modified with benzalkonium chloride (MMT-BAC@Cu(0)): as an eco-friendly and proficient heterogeneous nano-catalyst for green synthesis of 5-substituted 1H-tetrazoles.

In this study, Cu(0) nanoparticles supported on organo-modified montmorillonite with benzalkonium chloride (MMT-BAC@Cu(0)) were synthesized and used as an eco-friendly and green heterogeneous catalyst for the synthesis of 5-substituted 1H-tetrazoles in mild media. The structure of the catalyst was investigated using various techniques including XRD, EDX, ICP, TEM, FE-SEM, and FT-IR. The advantages of availability, low cost, non-toxicity, and biocompatibility of clay were our focus in synthesizing this nanoclay catalyst. The method's advantages include good to excellent product yields, mild conditions, easy work-up, short reaction times, and easy reuse of the nanocatalyst.

Synthesis of novel γ-butyrolactone-based phenazine compounds via microwave-assisted multicomponent domino reactions

Synthesis of novel γ-butyrolactone-based phenazine compounds via microwave-assisted multicomponent domino reactions

Green Synthesis of Spiro Compounds with Potential Anticancer Activity through Knoevenagel/Michael/Cyclization Multicomponent Domino Reactions Organocatalyzed by Ionic Liquid and Microwave-Assisted.

In this work a microwave-assisted Knoevenagel/Michael/cyclization multicomponent domino methodology, using ethanol as solvent and the ionic liquid 1-methylimidazolium chloride as catalyst was developed for the synthesis of spiro compounds. The reaction conditions considered ideal were determined from a methodological study varying solvent, catalyst, amount of catalyst, temperature, and heating mode. Finally, the generality of the methodology was evaluated by exploring the scope of the reaction, varying the starting materials (isatin, malononitrile, and barbituric acid). Overall, the twelve spiro compounds were synthesized in good yields (43-98%) and the X-ray structure of compound 1b was obtained. In addition, the in vitro antiproliferative activities of the spirocycles against four types of human cancer cell lines including HCT116 (human colon carcinoma), PC3 (prostate carcinoma), HL60 (promyelocytic leukemia), and SNB19 (astrocytoma) were screened by MTT-based assay. It is noteworthy that spiro compound 1c inhibited the four cell lines tested with the lowest IC50 values: 52.81 µM for HCT116, 74.40 µM for PC3, 101 µM for SNB19, and 49.72 µM for HL60.

Recent Advances in Green Synthesis of Functionalized Quinolines of Medicinal Impact (2018‐Present)

AbstractThe synthetic chemists are awakening to make substantial development in finding safer drugs against the rising communicable and non‐communicable type of diseases. By replacing traditional methods to more sustainable and greener approaches, multicomponent reactions are the rapid and efficient tool for the synthesis of organic molecules of structural diversity and complexity. Heterocyclic chemistry transforms small set of precursors into series of molecules by multicomponent domino reactions. This review covers recent trends of last five years (2018–2022) in construction of potentially drug‐like quinoline derivatives. The methods discussed here are preferable over conventional approaches being inexpensive, consuming lesser reaction time, atom economical, saving energy and manpower while avoiding toxic reagents/materials, chemical wastes and are environmental/occupational benign. The contributions covered here involve metallic, metal free strategies and other catalytic pathways including nanoparticles, ionic liquids and photocatalysis which are operationally safe and reliable.

A Green and Efficient NH4OAc-catalyzed Synthesis of 2-Hydroxy-3-(arylmethyl)(4-hydroxy-2-oxo-2,5-dihydrofuran-3-yl)-1,4-naphthoquinones

The green and efficient approach for synthesis of 2-hydroxy-3-(arylmethyl)(4-hydroxy-2-oxo-2,5-dihydrofuran-3-yl)-1,4-naphthoquinones starting from 2-hydroxy-1,4-naphthoquinone, tetronic acid, and aromatic aldehydes was developed. These reactions were carried out in ethanol under microwave irradiation in the presence of ammonium acetate as catalyst. These multicomponent domino reactions presumably occur via NH4OAc-catalyzed Mannich reaction - Michael addition - hydration - tautomerism - elimination sequence of reactions.

Transition-Metal-Free Domino Reaction of [60]Fullerene, Indole, and DMSO/HCl: One-Pot Access to Diverse N-Substituted [60]Fulleroindole Derivatives.

An unprecedented multicomponent domino reaction of [60]fullerene, indole, and DMSO/HCl has been developed for the one-pot efficient synthesis of diverse N-substituted [60]fulleroindole derivatives. This methodology features simple operation, low cost, and transition-metal-circumvented and good functional group tolerance in indole.

CuBr-promoted domino Biginelli reaction for the diastereoselective synthesis of bridged polyheterocycles: Mechanism studies and in vitro anti-tumor activities

The low-cost CuBr-promoted domino Biginelli reaction among readily available ketones, salicylaldehyde derivatives and 3-amino-1,2,4-triazole was studied under solvothermal conditions, giving the novel bridged polyheterocycles bearing two or three stereocenters depending on the starting ketones. This multicomponent reaction proceeded with high diastereoselectivity (dr > 20:1) based on a combined 1H NMR, crystallographic and supercritical fluid chromatographic (SFC) analysis of the product. Time-dependent high-resolution mass spectrometry (HRMS) was performed to track the reaction process, and several key intermediates were identified, leading to the drawing of a plausible reaction mechanism. Density functional theory (DFT) calculation was supplemented, and two reaction pathways were differentiated. Moreover, in vitro antitumor activity was evaluated using HeLa and HepG2 cell lines, and two of these polyheterocycles demonstrated promising activities against HepG2 cells with EC50 down to 10 µmol/L. Additionally, ESI-MS/MS studies on all the polyheterocycles suggest a common fragmentation pathway (loss of one molecule of amino-triazole) they shared, providing the first-hand fragmentation rules for future rapid structural identification of them. The multicomponent domino reaction presented here may offer prospects for future design of more efficient strategies to access medicinally important bridged polyheterocycles.

Environmentally friendly domino multicomponent strategy for the synthesis of pyrroloquinolinone hybrid heterocycles.

An efficient and elegant assembly of pyrene/aryl fused pyrrolo[2,3-b]quinolinone and pyrrolizino[3,2-b]quinolinone hybrid heterocycles was achieved via a domino multicomponent reaction strategy using a solid state melt reaction (SSMR) condition. The 1,3-dipole component was generated in situ from N-methylgylcine/l-proline and isatin, while the Baylis–Hillman adduct prepared from pyrene-1-carbaldehyde and various benzaldehydes is used as the dipolarophile. The domino protocol comprises 1,3-dipolar cycloaddition and a consequent double annulation reaction process. The advantages of this cascade protocol include environmentally friendly conditions, the avoidance of toxic organic solvents, simple work-up and good to excellent product yields.

Multicomponent Domino Synthesis of Highly Functionalized Aryl and Heteroaryl Fused Pyrroloquinolinone Ring Systems via Environmentally Benign Solid‐state Melt Reaction

AbstractA solid‐state melt reaction has been demonstrated via a domino multicomponent process for the synthesis of highly functionalized aryl/heteroaryl fused polycyclic pyrroloquinolinone frameworks in good to excellent yields. The multicomponent domino reaction sequence involves 1,3‐dipolar cycloaddition and concomitant double annulation reaction process. Baylis‐Hillman adducts derived from various aryl/heteroaryl aldehyde were used as dipolarophiles, while the 1,3‐dipole components were azomethine ylides generated in situ from indoline‐2,3‐dione and N‐methylglycine/L‐proline/L‐pipecolinic acid. The reaction is highly regio and stereoselective, atom economic and environmentally benign in nature. The structure of compounds was elucidated through spectroscopic techniques and unambiguously ascertained by single crystal X‐diffraction analysis.

Recent Advancement in the Copper Mediated Synthesis of Heterocyclic Amides as Important Pharmaceutical and Agrochemicals

AbstractCopper with variable oxidation states, Earth abundance was used as a tunable and multifunctional catalyst promoting organic transformations. Copper‐based catalytic materials have been effectively utilized in bioorganic chemistry, material science, and natural products synthesis. Several organic transformations involving cycloadditions, cyclizations, cross‐couplings, and condensations in one‐pot assist in the formation of multiple bonds like C−C/C−O bonds, C−C/C−N bonds, and C−N/C−S bonds. Copper has recently been explored as efficient catalytic material for the synthesis of heterocyclic amides. Heterocyclic amides are essential organic compounds are quite prevelent in the pharmaceuticals, fine chemicals and natural products. The heterocyclic amides are the key components of multivarious ace drugs and bio‐molecules like peptides and proteins, and several natural products. Therefore, heterocyclic amides are of much significance, and research focusing on the facile methods is of much interest to contemporary synthetic chemists. Different techniques have been developed using copper‐based catalysts for the synthesis of heterocyclic amdes. These heterocyclic amides are prepared by the reaction of C(sp3)−H, C(sp2)−H, C(sp)−H bonds, aldehydes, ketones, carboxylic acid, carboxylic acid‐based surrogates, and amine surrogates. N‐alkyation of amides with multifarious substrates has been the extensively investigated for the synthesis of heterocyclic amides. Finally, multicomponent domino reactions have also been investigated for the synthesis of heterocycic amides. The present review summarises various synthetic techniques for the copper catalyzed heterocyclic amides synthesis.

Modular Assembly of Polyfunctional Arenes with Three Contiguous And Different Substituents by Orchestrating Pd-Catalyzed Multi-Component Domino Reactions

By orchestrating mechanistically sequential and compatible palladium-catalyzed domino carbopalladation of arynes and norbornene (NBE)-mediated Catellani processes, polyfunctional arenes with three contiguous and different substituents could be efficiently assembled under mild conditions in an one-pot four-component modular way. Optimization on the reaction conditions revealed that balancing the reaction parameters in general, and loading amount of NBE especially, was a linchpin for the reaction. Studies on the reaction scope indicated a wide selection of functional groups, including complex natural product derived substructures, could be tolerated, making it appealing in both early and late-stage assemblies. Post-transformations showed that not only the newly installed substituents but also the parent aromatic nucleus could be conveniently derived, enabling polyfunctional arenes with diverse substitutions in a concise manner.

A Four-Component Domino Reaction: An Eco-Compatible and Highly Efficient Construction of 1,8-Naphthyridine Derivatives, Their In Silico Molecular Docking, Drug Likeness, ADME, and Toxicity Studies

A multicomponent domino reaction of enaminone, malononitrile, and o-phthalaldehyde has been established, providing direct access to novel highly functionalized pentacyclic cyclopenta [b] indeno [1, 2, 3-de] [1,8] naphthyridine derivatives. The simplicity of execution, readily available substrates, high yields, excellent functional group tolerance, scalability, and good scores of environmental parameters make this synthetic strategy more sustainable and worthy of further attention. This one-pot transformation, which involved multiple steps and did not require the use of a catalyst, constructed four new C-C bonds, two new C-N bonds, and three new rings, with efficient use of all reactants. Furthermore, we performed in silico molecular docking analysis for prediction of anticancer (against human topoisomerase IIβ protein) and antimicrobial (against E.coli. DNA gyrase B protein) activities. Drug likeness and ADMET studies were also predicted. Overall investigation indicates that compound 6i may serve as a candidate that could be developed as potential anticancer and antimicrobial agent among all.

Synthesis of novel potent cytotoxicy podophyllotoxin-naphthoquinone compounds via microwave-assited multicomponent domino reactions

A series of novel podophyllotoxin-naphthoquinone compounds 5a-p were synthesized in good yields using microwave-assisted four-component reactions of 2-hydroxy-1,4-naphthoquinone, aromatic benzaldehydes, tetronic acid and ammonium acetate. All the synthesized compounds were fully characterized by spectral data and evaluated for their cytotoxicity activities against KB, HepG2, Lu1, MCF7, and non-cancerous Hek-293 cell lines. Among 16 new compounds screened, compounds 5a, 5d, 5h, and 5k displayed high potent inhibitory activities with IC50 < 40 nM against HepG2 and SK-Lu-1 cell lines, and showed lower toxicity for non-cancerous Hek-293 cell line, demonstrating the potential importance of these compounds in the development of potential anticancer agents.