One-pot synthesis of 1,2,4,5-tetrahydro-2,4-dioxobenzo[b][1,4]diazepine and malonamide derivatives using multi-component reactions

Metal-bio functionalized bismuthmagnetite [Fe3-x Bi x O4/SiO2@l-ArgEt3 +I-/Zn(ii)]: a novel bionanocomposite for the synthesis of 1,2,4,5-tetrahydro-2,4-dioxobenzo[b][1,4]diazepine malononitriles and malonamides at room temperature and under sonication

In this work, a new magnetized composite of bismuth (Fe_3−xBi_xO₄) was prepared and functionalized stepwise with silica, triethylargininium iodide ionic liquid, and Zn(ii) to prepare a multi-layered core–shell bio-nanostructure, [Fe_3−xBi_xO₄/SiO₂@l-ArgEt₃⁺I⁻/Zn(ii)]. The modified bismuth magnetic amino acid-containing nanocomposite was characterized using several techniques including Fourier-transform infrared (FT-IR), X-ray fluorescence (XRF), vibrating sample magnetometer (VSM), field-emission scanning electron microscopy (FESEM), energy dispersive X-ray analysis (EDAX), thermogravimetric/differential scanning calorimetric (TGA/DSC) analysis, X-ray photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller (BET), and inductively coupled plasma-optical emission spectrometry (ICP-OES). The magnetized bionanocomposite exhibited high catalytic activity for the synthesis of 1,2,4,5-tetrahydro-2,4-dioxobenzo[b][1,4]diazepine malononitriles via five-component reactions between 1,2-phenylenediamines, Meldrum's acid, malononitrile, aldehydes, and isocyanides at room temperature in ethanol. The efficacy of this protocol was also examined to obtain malonamide derivatives via pseudo six-component reactions of 1,4-phenylenediamine, Meldrum's acid, malononitrile, aldehydes, and isocyanides. When the above-mentioned MCRs were repeated under the same conditions with the application of sonication, a notable decrease in the reaction time was observed. The recovery and reusability of the metal-bio functionalized bismuthmagnetite were examined successfully in 3 runs. Furthermore, the characteristics of the recovered Fe_3−xBi_xO₄/SiO₂@l-ArgEt₃⁺I⁻/Zn(ii) were investigated though FESEM and EDAX analysis.

In this work, a new magnetized composite of bismuth (Fe_3−xBi_xO₄) was prepared and functionalized stepwise with silica, triethylargininium iodide ionic liquid, and Zn(ii) to prepare a multi-layered core–shell bio-nanostructure, [Fe_3−xBi_xO₄/SiO₂@l-ArgEt₃⁺I⁻/Zn(ii)].

Arylidenemalononitriles as Versatile Synthons in Heterocyclic Synthesis

BACKGROUND

Arylidenemalononitriles are valuable synthons for the construction of a variety of novel complex heterocyclic motifs, fused heterocycle derivatives and spirocyclic compounds. They are versatile chemical intermediates and have increasing applications in industry, agriculture, medicine, biological science.

OBJECTIVE

The aim of this review is to highlight the preparation methods and reactions of arylidenemalononitriles in the synthesis of various heterocyclic compounds.

CONCLUSION

In this review, we have presented the application of arylidenemalononitriles to construct a variety of heterocycles. Various catalysts for the preparation of arylidnemalononitriles have been described.

Multicomponent reactions as a potent tool for the synthesis of benzodiazepines

Benzodiazepines (BZDs), a diverse class of benzofused seven-membered N-heterocycles, display essential pharmacological properties and play vital roles in some biochemical processes. They have mainly been prescribed as potential therapeutic agents, which interestingly represent various biological activities such as anticancer, anxiolytic, antipsychotic, anticonvulsant, antituberculosis, muscle relaxant, and antimicrobial activities. The extensive biological activities of BZDs in various fields have encouraged medicinal chemists to discover and design novel BZD-based scaffolds as potential therapeutic candidates with the favorite biological activity through an efficient protocol. Although certainly valuable and important, conventional synthetic routes to these bicyclic benzene compounds contain methodologies often requiring multistep procedures, which suffer from waste materials generation and lack of sustainability. By contrast, multicomponent reactions (MCRs) have recently advanced as a green synthetic strategy for synthesizing BZDs with the desired scope. In this regard, MCRs, especially Ugi and Ugi-type reactions, efficiently and conveniently supply various complex synthons, which can easily be converted to the BZDs via suitable post-transformations. Also, MCRs, especially Mannich-type reactions, provide speedy and economic approaches for the one-pot and one-step synthesis of BZDs. As a result, various functionalized-BZDs have been achieved by developing mild, efficient, and high-yielding MCR protocols. This review covers all aspects of the synthesis of BZDs with a particular focus on the MCRs as well as the mechanism chemistry of synthetic protocols. The present manuscript opens a new avenue for organic, medicinal, and industrial chemists to design safe, environmentally benign, and economical methods for the synthesis of new and known BZDs.

Access to molecular complexity. Multicomponent reactions involving five or more components

The evaluation of the significance of a chemical transformation addresses many factors, including such important characteristics as the number of chemical bonds formed in one step, the reaction time, labour intensity, the cost of reactants and catalysts and so on. The amount of waste produced in the reaction has also gained increasing importance in recent years. Multicomponent reactions (MCRs) occupy a special place as a synthetic tool in modern organic chemistry. These reactions allow the synthesis of target products with complex structures, minimizing labour costs. This review summarizes the literature on multicomponent reactions involving five or more components. The data in the review are classified according to the number of reactants participating in the reaction and the types of reactions. It is worth noting that in some cases, these transformations can be a part of a domino process, making this classification difficult, if not impossible. The structural diversity of the reaction products greatly increases with increasing number of components involved in the MCR, which becomes virtually unlimited when using combinations of MCRs. This review highlights the main trends of past decades in the field of MCRs. The last two decades have witnessed an explosive growth in the number of publications in this area of chemistry.

The bibliography includes 309 references.

The status of isocyanide-based multi-component reactions in Iran (2010-2018)

Isocyanides as key intermediates and magic reactants have been widely applied in organic reactions for direct access to a broad spectrum of remarkable organic compounds. Although the history of these magical compounds dates back more than 100 years, it still has been drawing widespread attention of chemists who confirmed their versatility and effectiveness. Because of their wide spectrum of pharmacological, industrial and synthetic applications, many reactions with the utilization of isocyanides are reported in the literature. In this context, Iranian scientist played a significant role in the growth of isocyanides chemistry. The present review article covers literature from the period starting from 2010 onward and encompasses new synthetic routes and organic transformation involving isocyanides by Iranian researchers. During this period, a diverse range of isocyanide-based multi-component reactions (I-MCRs) has been reported such as a new modification of Ugi, post-Ugi, Passerini and Groebke-Blackburn-Bienayme condensation reactions, isocyanide-based [1 + 4] cycloaddition reactions, isocyanide-acetylene-based MCRs, isocyanide and Meldrum's acid-based MCRs, several unexpected reactions besides green mediums and novel catalytic systems for the synthesis of diverse kinds of pharmaceutically and industrially remarkable heterocyclic and linear organic compounds. This review also emphasizes the neoteric applications of I-MCR for the synthesis of valuable peptide and pseudopeptide scaffolds, enzyme immobilization and functionalization of materials with tailorable properties that can play important roles in the plethora of applications.

Crystal structure of ethyl (E)-1-(3-ethoxy-3-oxoprop-1-en-1-yl)-2-(4-nitrophenyl)-2,5-dihydro-1H-benzo[b][1,4]diazepine-3-carboxylate, C23H23N3O6

C23H23N3O6, monoclinic, P21/c (no. 14), a = 11.235(6) Å, b = 11.251(7) Å, c = 17.814(10) Å, β = 98.872(12)°, V = 2225(2) Å3, Z = 4, R gt(F) = 0.0581, wR ref(F 2) = 0.1590, T = 296(2) K.

A Metal-Free Regioselective Multicomponent Approach for the Synthesis of Free Radical Scavenging Pyrimido-Fused Indazoles and Their Fluorescence Studies

This study deals with a new and efficient metal-free regioselective synthesis of pyrimido-fused indazoles with nitrogen ring junction motifs. We have developed a metal-free domino type reaction between 3-aminoindazole, aryl aldehydes and aceotophenones in the presence of KOH/DMF that leads to pyrimido[1,2-b]indazole analogues. Response Surface Methodology (RSM) coupled with a Box-Behnken design (BBD) were utilized for exploring the effect of base used (A), temperature of reaction (B) and (C), reaction time. This approach can allow access to a variety of pyrimidoindazole fluorophores and related compounds. The compound N,N-dimethyl-4-(2-phenylpyrimido[1,2-b]indazol-4-yl)aniline (4e) displays the maximum fluorescence intensity at 518 nm and shows a fluorescence quantum yield of 0.068. The synthesized pyramido-fused indazoles have been evaluated for their free radical scavenging activity and compound 4f showed good antioxidant activity.

Isocyanide and Meldrum's acid-based multicomponent reactions in diversity-oriented synthesis: from a serendipitous discovery towards valuable synthetic approaches

Multicomponent reactions, which lead to synthesis of target compounds with inherent molecular diversity, greater efficiency and atom economy, are single step types of reactions made from three or more reactants attract the attention of all chemists.