Academic literature on the topic 'Solvent-free multi-component reactions'

Herein, we demonstrate that several reactions can be telescoped into a single continuous process and/or be carried out as a continuous multi-component reaction (MCR), by twin screw extrusion (TSE), in the complete absence of solvent.

Considering the very important medicinal and biological properties of heterocycles including isatin skeleton, synthesis of isatin-containing compounds has attracted the attention of medicinal and organic chemists, especially researchers involved in the synthesis of heterocycles. The present review focuses on the recent investigation in the synthesis of heterocycles with isatin moiety using isatin derivatives as reaction reactants via multi-component for the period of 2014–2024. The reports were classified according to the conditions of the reactions, which distinguishes this review from similar studies. In some reports, green chemistry has been used, such as the use of green solvent, green and reusable catalyst, solvent-free conditions, microwave irradiations and ultrasonic irradiations. Most reviews of isatin published so far have focused only on spirooxindoles, but this review not only addresses the condition for the synthesis of spirooxindoles, but also the synthesis of other isatin-contaning heterocycles such as pyrroloquinolines, imidazole-indoles and pyrazoloquinoline. The main objective of this review is to present an overview of the latest methodologies involving isatin in the multicomponent synthesis of heterocyclic compounds, specifically for organic and medicinal chemists.

A simple, efficient and high-yielding one-pot protocol for the synthesis of novel functionalised 4H-chromenes and chromene carboxylic acids has been developed using multi-component domino coupling reactions of anil-like compounds with 1,3-diketones and indole in the presence of formic acid catalyst under solvent-free conditions. The protocol avoids the use of expensive catalysts, toxic solvents and chromatographic separation.

In the work, the preparation, characterization and use of Fe₃O₄@SiO₂–ZrCl₂-MNPs as nano magnetic reagents in the promotion of some multi-component reactions is reported.

A new-fangled, proficient, one-pot multi component, intramolecular C-S bond formation reaction, mediated by phase transfer catalyst, Triton-B, is described in this paper. The reaction of alkyl/ phenyl amines, CS2 and formaldehyde catalyzed via Triton-B resulted in formation of 3-(Alkyl or aryl methyl),5-(Alkyl or aryl methyl) substituted tetrahydro-2H-1,3,5-thiadiazine-2-thiones compounds(1a-15a). These compounds (1a-15a) were characterized with the help of elemental analysis, IR, NMR and mass spectroscopic methods. The PTC mediated reactions require mild reaction condition and reduced time period for completion. The reaction is achieved at normal temperature under solvent free conditions with good yields and great selectivity. This methodology discourages the traditional synthesis method of inorganic base for such coupling reaction.

This study introduces an environmentally sustainable approach for the synthesis of 3,4-dihydropyrimidin-2(1H)-ones (DHPMs), via the Biginelli reaction. A heterogeneous catalyst, Heteropolyacid-Clay (HPA-Clay), is developed by immobilizing H5PV2W10O40 on Montmorillonite KSF clay. The catalyst exhibits enhanced stability and catalytic efficiency, confirmed through X-ray powder diffraction and scanning electron microscopy. Utilizing a one-pot multi-component strategy under solvent-free conditions, various aldehydes, urea or thiourea, and ethylacetoacetate generate DHPMs with excellent yields and reduced reaction times. Catalysed by 2 mol% HPA-Clay, the process aligns with green chemistry principles, emphasizing cost-efficiency, environmental sustainability, and recyclability. The catalyst demonstrates consistent activity over multiple cycles, highlighting its potential for advancing Biginelli reactions.

The catalytic efficiency of silver nanoparticles supported on chitosan as a green, robust, and efficient nanocatalyst for the direct synthesis of biologically active compounds, such as: imidazole derivatives as well as pyrazine scaffolds through multi-component reactions strategy, have been demonstrated. In this work, imidazole derivatives were achieved via pseudo four-component reactions by utilization of benzaldehydes, benzils, anilines, and ammonium acetate under solvent-free conditions. Moreover, pyrazine scaffolds were synthesized through a three-component reaction of phenylenediamine derivatives, isocyanides and various ketones in water. The main advantages of this protocol are the reusability of the catalyst, operational simplicity, mild reaction conditions, and high-yielding. Copyright © 2019 BCREC Group. All rights reservedReceived: 19th January 2018; Revised: 10th September 2018; Accepted: 18th September 2018; Available online: 25th January 2019; Published regularly: April 2019How to Cite: Hamzavi, S.F., Jamili, S., Yousefzadi, M., Moradi, A.M., Biuki, N.A. (2019). Silver Nanoparticles Supported on Chitosan as a Green and Robust Heterogeneous Catalyst for Direct Synthesis of Nitrogen Heterocyclic Compounds under Green Conditions. Bulletin of Chemical Reaction Engineering & Catalysis, 14 (1): 51-59 (doi:10.9767/bcrec.14.1.2105.51-59)Permalink/DOI: https://doi.org/10.9767/bcrec.14.1.2105.51-59

Abstract 3D scaffolds are known to be used in bone tissue engineering applications due to their great potential of providing multi-functionalized environment for cells. Different production techniques have been used focusing on changing geometrical features or adding biological/chemical compounds to improve the functionality of current 2D/3D scaffolds. A critical component to this functionalization relates to the effect of endogenous and exogeneous growth factors (GF) in the bone regeneration process that could be incorporated to the scaffolds via Initiated Chemical Vapor Deposition (iCVD) which is a solvent free method that requires low energy while also containing a wide variety of monomer choices for the layer by layer coating of polymers with individual functionality choices. However, GFs come with several difficulties such as rapid deactivation, low protein stability profile and little time of half-life, hence ideal environments that can overcome these issues are yet to be defined. Towards that goal, in this study we develop a computational framework based on the implementation of the advection-diffusion-reaction Partial Differential Equations (PDE) in a Finite Element Analysis (FEA) solver in COMSOL Multiphysics software. The goal is to develop a tool and conduct an initial analysis to be utilized for the simulation of multi-layer scaffold functionalized using encapsulation and immobilization of GFs inside nanoparticles possibly via iCVD. In this paper we focus on the analysis of two typical GF (BMP-2 and TGF) release mechanisms based on the effect of key material and geometrical parameters such as thickness of layers, initial GF concentration, diffusion coefficient, release function and uptake rate (absorption coefficient). The ultimate goal is to develop a model that can be used for future bone scaffold design studies when integrated to more advanced optimization methodologies. This model with further integration and updates of chemical and biological parameter measurements and inclusion of presence of antibodies should lay down a valuable basis for directing possible experimental functionalization efforts and their effects on the healing process of bone tissue. Initial results indicate that the proposed computational model can be utilized to predict the response of multi-layered bone scaffolds in terms of the concentration profiles of the GFs. Results of the parametric study presented in this paper prompt for the relative importance of each parameter in tuning the GF release profiles and point towards the need for formal optimization studies to achieve desired GF release responses considering all factors simultaneously. Among them, the diffusion coefficient is a key parameter with both a dominant effect on the GF profile and its ability to characterize different coatings using iCVD methods. As a next step, the developed framework will be updated to incorporate more detailed surface reactions and morphological data to simulate iCVD coated growth factors and verified with possible in-vitro studies before its integration to a formal optimization methodology.