CINXE.COM

<!DOCTYPE html> <html lang="en" dir="ltr"> <head>  <script async src="https://www.googletagmanager.com/gtag/js?id=G-P63WKM1TM1"></script> <script> window.dataLayer = window.dataLayer || []; function gtag(){dataLayer.push(arguments);} gtag('js', new Date()); gtag('config', 'G-P63WKM1TM1'); </script>  <script type="text/javascript" > (function(m,e,t,r,i,k,a){m[i]=m[i]||function(){(m[i].a=m[i].a||[]).push(arguments)}; m[i].l=1*new Date(); for (var j = 0; j < document.scripts.length; j++) {if (document.scripts[j].src === r) { return; }} k=e.createElement(t),a=e.getElementsByTagName(t)[0],k.async=1,k.src=r,a.parentNode.insertBefore(k,a)}) (window, document, "script", "https://mc.yandex.ru/metrika/tag.js", "ym"); ym(55165297, "init", { clickmap:false, trackLinks:true, accurateTrackBounce:true, webvisor:false }); </script> <noscript><div><img src="https://mc.yandex.ru/watch/55165297" style="position:absolute; left:-9999px;" alt="" /></div></noscript>    <title>Search results for: regioselectivity</title> <meta name="description" content="Search results for: regioselectivity"> <meta name="keywords" content="regioselectivity"> <meta name="viewport" content="width=device-width, initial-scale=1, minimum-scale=1, maximum-scale=1, user-scalable=no"> <meta charset="utf-8"> <link href="https://cdn.waset.org/favicon.ico" type="image/x-icon" rel="shortcut icon"> <link href="https://cdn.waset.org/static/plugins/bootstrap-4.2.1/css/bootstrap.min.css" rel="stylesheet"> <link href="https://cdn.waset.org/static/plugins/fontawesome/css/all.min.css" rel="stylesheet"> <link href="https://cdn.waset.org/static/css/site.css?v=150220211555" rel="stylesheet"> </head> <body> <header> <div class="container"> <nav class="navbar navbar-expand-lg navbar-light"> <a class="navbar-brand" href="https://waset.org"> <img src="https://cdn.waset.org/static/images/wasetc.png" alt="Open Science Research Excellence" title="Open Science Research Excellence" /> </a> <button class="d-block d-lg-none navbar-toggler ml-auto" type="button" data-toggle="collapse" data-target="#navbarMenu" aria-controls="navbarMenu" aria-expanded="false" aria-label="Toggle navigation"> <span class="navbar-toggler-icon"></span> </button> <div class="w-100"> <div class="d-none d-lg-flex flex-row-reverse"> <form method="get" action="https://waset.org/search" class="form-inline my-2 my-lg-0"> <input class="form-control mr-sm-2" type="search" placeholder="Search Conferences" value="regioselectivity" name="q" aria-label="Search"> <button class="btn btn-light my-2 my-sm-0" type="submit"><i class="fas fa-search"></i></button> </form> </div> <div class="collapse navbar-collapse mt-1" id="navbarMenu"> <ul class="navbar-nav ml-auto align-items-center" id="mainNavMenu"> <li class="nav-item"> <a class="nav-link" href="https://waset.org/conferences" title="Conferences in 2024/2025/2026">Conferences</a> </li> <li class="nav-item"> <a class="nav-link" href="https://waset.org/disciplines" title="Disciplines">Disciplines</a> </li> <li class="nav-item"> <a class="nav-link" href="https://waset.org/committees" rel="nofollow">Committees</a> </li> <li class="nav-item dropdown"> <a class="nav-link dropdown-toggle" href="#" id="navbarDropdownPublications" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false"> Publications </a> <div class="dropdown-menu" aria-labelledby="navbarDropdownPublications"> <a class="dropdown-item" href="https://publications.waset.org/abstracts">Abstracts</a> <a class="dropdown-item" href="https://publications.waset.org">Periodicals</a> <a class="dropdown-item" href="https://publications.waset.org/archive">Archive</a> </div> </li> <li class="nav-item"> <a class="nav-link" href="https://waset.org/page/support" title="Support">Support</a> </li> </ul> </div> </div> </nav> </div> </header> <main> <div class="container mt-4"> <div class="row"> <div class="col-md-9 mx-auto"> <form method="get" action="https://publications.waset.org/abstracts/search"> <div id="custom-search-input"> <div class="input-group"> <i class="fas fa-search"></i> <input type="text" class="search-query" name="q" placeholder="Author, Title, Abstract, Keywords" value="regioselectivity"> <input type="submit" class="btn_search" value="Search"> </div> </div> </form> </div> </div> <div class="row mt-3"> <div class="col-sm-3"> <div class="card"> <div class="card-body"><strong>Commenced</strong> in January 2007</div> </div> </div> <div class="col-sm-3"> <div class="card"> <div class="card-body"><strong>Frequency:</strong> Monthly</div> </div> </div> <div class="col-sm-3"> <div class="card"> <div class="card-body"><strong>Edition:</strong> International</div> </div> </div> <div class="col-sm-3"> <div class="card"> <div class="card-body"><strong>Paper Count:</strong> 10</div> </div> </div> </div> <h1 class="mt-3 mb-3 text-center" style="font-size:1.6rem;">Search results for: regioselectivity</h1> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">10</span> Investigation of the Mechanism, Régio and Sterioselectivity Using the 1,3-Dipolar Cycloaddition Reaction of Fused 1h-Pyrrole-2,3-Diones with Nitrones: Molecular Electron Density Theory Study</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Ameur%20Soukaina">Ameur Soukaina</a>, <a href="https://publications.waset.org/abstracts/search?q=Zeroual%20Abdellah"> Zeroual Abdellah</a>, <a href="https://publications.waset.org/abstracts/search?q=Mazoir%20Noureddine"> Mazoir Noureddine</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Molecular Electron Density Theory (MEDT) elucidates the regioselectivity of the [4+2] cycloaddition reaction between 3-aroylpyrrolo[1,2-α]quinoxaline-1,2,4(5H)-trione and butyl vinyl ether Regioselectivity and stereoselectivity. The regioselectivity mechanisms of these reactions were investigated by evaluating potential energy surfaces calculated for cycloaddition processes and DFT density-based reactivity indices. These methods have been successfully applied to predict preferred regioisomers for different method alternatives. Reactions were monitored by performing transition state optimizations, calculations of intrinsic reaction coordinates, and activation energies. The observed regioselectivity was rationalized using DFT-based reactivity descriptors such as the Parr function. Solvent effects were also investigated in 1,4-dioxane solvent using a field model for self-consistent reactions. The results were compared with experimental data to find good agreement. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=cycloaddition" title="cycloaddition">cycloaddition</a>, <a href="https://publications.waset.org/abstracts/search?q=DFT" title=" DFT"> DFT</a>, <a href="https://publications.waset.org/abstracts/search?q=ELF" title=" ELF"> ELF</a>, <a href="https://publications.waset.org/abstracts/search?q=MEDT" title=" MEDT"> MEDT</a>, <a href="https://publications.waset.org/abstracts/search?q=parr" title=" parr"> parr</a>, <a href="https://publications.waset.org/abstracts/search?q=stereoselectivit%C3%A9" title=" stereoselectivité"> stereoselectivité</a> </p> <a href="https://publications.waset.org/abstracts/148675/investigation-of-the-mechanism-regio-and-sterioselectivity-using-the-13-dipolar-cycloaddition-reaction-of-fused-1h-pyrrole-23-diones-with-nitrones-molecular-electron-density-theory-study" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/148675.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">108</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">9</span> Prediction of the Regioselectivity of 1,3-Dipolar Cycloaddition Reactions of Nitrile Oxides with 2(5H)-Furanones Using Recent Theoretical Reactivity Indices</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Imad%20Eddine%20Charif">Imad Eddine Charif</a>, <a href="https://publications.waset.org/abstracts/search?q=Wafaa%20Benchouk"> Wafaa Benchouk</a>, <a href="https://publications.waset.org/abstracts/search?q=Sidi%20Mohamed%20Mekelleche"> Sidi Mohamed Mekelleche</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The regioselectivity of a series of 16 1,3-dipolar cycloaddition reactions of nitrile oxides with 2(5H)-furanones has been analysed by means of global and local electrophilic and nucleophilic reactivity indices using density functional theory at the B3LYP level together with the 6-31G(d) basis set. The local electrophilicity and nucleophilicity indices, based on Fukui and Parr functions, have been calculated for the terminal sites, namely the C1 and O3 atoms of the 1,3-dipole and the C4 and C5 atoms of the dipolarophile. These local indices were calculated using both Mulliken and natural charges and spin densities. The results obtained show that the C5 atom of the 2(5H)-furanones is the most electrophilic site whereas the O3 atom of the nitrile oxides is the most nucleophilic centre. It turns out that the experimental regioselectivity is correctly reproduced, indicating that both Fukui- and Parr-based indices are efficient tools for the prediction of the regiochemistry of the studied reactions and could be used for the prediction of newly designed reactions of the same kind. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=1" title="1">1</a>, <a href="https://publications.waset.org/abstracts/search?q=3-dipolar%20cycloaddition" title="3-dipolar cycloaddition">3-dipolar cycloaddition</a>, <a href="https://publications.waset.org/abstracts/search?q=density%20functional%20theory" title=" density functional theory"> density functional theory</a>, <a href="https://publications.waset.org/abstracts/search?q=nitrile%20oxides" title=" nitrile oxides"> nitrile oxides</a>, <a href="https://publications.waset.org/abstracts/search?q=regioselectivity" title=" regioselectivity"> regioselectivity</a>, <a href="https://publications.waset.org/abstracts/search?q=reactivity%20indices" title=" reactivity indices"> reactivity indices</a> </p> <a href="https://publications.waset.org/abstracts/92661/prediction-of-the-regioselectivity-of-13-dipolar-cycloaddition-reactions-of-nitrile-oxides-with-25h-furanones-using-recent-theoretical-reactivity-indices" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/92661.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">166</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">8</span> Theoretical Evaluation of Oxirane and Aziridine Opening Regioselectivity, Solvent Effect, and Strength of Nucleophilic and Nucleofugal Groups for the Preparation of Benzimidazole-Fused 1,4-Benzoxazepine</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=M.%20Abdoul-Hakim">M. Abdoul-Hakim</a>, <a href="https://publications.waset.org/abstracts/search?q=a.%20Zeroual">a. Zeroual</a>, <a href="https://publications.waset.org/abstracts/search?q=H.%20Garmes">H. Garmes</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In a route for the preparation of 1,4-benzoxazepine fused to benzimidazole, the use of 2-(2-methoxyphenyl)-benzimidazole or styrene-derived N-tosylaziridine does not give the desired products. On this basis, we theoretically studied this reaction using DFT at the B3LYP/6-31+G(d) level. The analysis of the results shows a preferential nucleophilic attack of 2-(2-fluorophenyl)-benzimidazole on the terminal carbon atom of the Alkylepoxides and on the substituted carbon of N-tosylaziridine. Taking into account the solvent effect (DMF) makes the reactions spontaneous for the opening of epoxides and N-tosylaziridine and disfavors the intramolecularnucleophilic aromatic substitution reaction step of the products of the attack of 2-(2-methoxyphenyl)benzimidazole on an epoxide and those of the opening of N-tosylaziridine, which is consistent with the experiment. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=alkylepoxides" title="alkylepoxides">alkylepoxides</a>, <a href="https://publications.waset.org/abstracts/search?q=4-benzoxazepine%20fused%20to%20benzimidazole%20imine" title=" 4-benzoxazepine fused to benzimidazole imine"> 4-benzoxazepine fused to benzimidazole imine</a>, <a href="https://publications.waset.org/abstracts/search?q=benzonitrile%20N-oxide" title=" benzonitrile N-oxide"> benzonitrile N-oxide</a>, <a href="https://publications.waset.org/abstracts/search?q=DFT" title=" DFT"> DFT</a>, <a href="https://publications.waset.org/abstracts/search?q=intramolecular%20nucleophilic%20aromatic%20substitution" title=" intramolecular nucleophilic aromatic substitution"> intramolecular nucleophilic aromatic substitution</a>, <a href="https://publications.waset.org/abstracts/search?q=N-tosyl%20aziridine" title=" N-tosyl aziridine"> N-tosyl aziridine</a> </p> <a href="https://publications.waset.org/abstracts/148785/theoretical-evaluation-of-oxirane-and-aziridine-opening-regioselectivity-solvent-effect-and-strength-of-nucleophilic-and-nucleofugal-groups-for-the-preparation-of-benzimidazole-fused-14-benzoxazepine" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/148785.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">142</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">7</span> Synthesis, Characterization of Benzodiazepine Derivatives through Condensation Reaction, Crystal Structure, and DFT Calculations</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Samir%20Hmaimou">Samir Hmaimou</a>, <a href="https://publications.waset.org/abstracts/search?q=Marouane%20Ait%20Lahcen"> Marouane Ait Lahcen</a>, <a href="https://publications.waset.org/abstracts/search?q=Mohamed%20Adardour"> Mohamed Adardour</a>, <a href="https://publications.waset.org/abstracts/search?q=Mohamed%20Maatallah"> Mohamed Maatallah</a>, <a href="https://publications.waset.org/abstracts/search?q=Abdesselam%20Baouid"> Abdesselam Baouid</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The stereoisomers (E)-2,2-dimethyl-4-(4-subsitutedstyryl)-2,3-dihydro-1H-[1,5]-benzodiazepine 3(a-d) were synthesized via the condensation reaction of 2,2,3 4-trimethyl-2,3-dihydro-1H-1,5-benzodiazepine (BZD) 1 with the benzaldehyde derivatives 2(a-d) in polar protic solvent as ethanol. The chemical structure of the prepared products was confirmed by NMR (¹H and ¹³C), HRMS, and X-ray analysis of the crystal structure 3d. The condensation reaction was examined using DFT calculations at the theoretical level of B3LYP/6-311G(d,p). Frontier molecular orbital analysis shows that the most favorable interaction is between the HOMO of BZD 1 and the LUMO of 2(a-d). On the other hand, the calculation of the global reactivity indices (softness, hardness, and chemical potential) confirmed that benzodiazepine BDZ 1 act as a nucleophile, whereas the aldehyde derivatives 2(a-d) play the role of electrophile. Furthermore, we identified each reagent's reactive sites by the measurement of the reactivity indices to explain the experimentally observed regioselectivity, using Fukui local reactivity descriptors. A one-step mechanism reaction and order 2 water elimination were investigated. We also looked at how the electron-withdrawing groups (EWG) of various aldehydes affected the reaction's mechanism and the stability of products 3(a-d). <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=benzodiazepine" title="benzodiazepine">benzodiazepine</a>, <a href="https://publications.waset.org/abstracts/search?q=DFT%20calculations" title=" DFT calculations"> DFT calculations</a>, <a href="https://publications.waset.org/abstracts/search?q=crystal%20structure" title=" crystal structure"> crystal structure</a>, <a href="https://publications.waset.org/abstracts/search?q=regioselective" title=" regioselective"> regioselective</a>, <a href="https://publications.waset.org/abstracts/search?q=condensation%20Reaction" title=" condensation Reaction"> condensation Reaction</a> </p> <a href="https://publications.waset.org/abstracts/192346/synthesis-characterization-of-benzodiazepine-derivatives-through-condensation-reaction-crystal-structure-and-dft-calculations" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/192346.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">14</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">6</span> Synthesis, Characterization, and Quantum Investigations on [3+2] Cycloaddition Reaction of Nitrile Oxide with 1,5-Benzodiazepine</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Samir%20Hmaimou">Samir Hmaimou</a>, <a href="https://publications.waset.org/abstracts/search?q=Marouane%20Ait%20Lahcen"> Marouane Ait Lahcen</a>, <a href="https://publications.waset.org/abstracts/search?q=Mohamed%20Adardour"> Mohamed Adardour</a>, <a href="https://publications.waset.org/abstracts/search?q=Mohamed%20Maatallah"> Mohamed Maatallah</a>, <a href="https://publications.waset.org/abstracts/search?q=Abdesselam%20Baouid"> Abdesselam Baouid</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Due to (3 + 2) cycloaddition and condensation reaction, a wide range of synthetic routes can be used to obtain biologically active heterocyclic compounds. Condensation and (3+2) cycloaddition reactions in heterocyclic syntheses are versatile due to the wide variety of possible combinations of several atoms of the reactants. In this article, we first outline the synthesis of benzodiazepine 4 with two dipolarophilic centers (C=C and C=N) by condensation reaction. Then, we use it for cycloaddition reactions (3+2) with nitrile oxides to prepare oxadiazole-benzodiazepines and pyrazole-benzodiazepine compounds. ¹H and ¹³C NMR are used to establish all the structures of the synthesized products. These condensation and cycloaddition reactions were then analyzed using density functional theory (DFT) calculations at the B3LYP/6-311G(d,p) theoretical level. In this study, the mechanism of the one-step cycloaddition reaction was investigated. Molecular electrostatic potential (MEP) was used to identify the electrophilic and nucleophilic attack sites of the molecules studied. Additionally, Fukui investigations (electrophilic f- and nucleophilic f+) in the various reaction centers of the reactants demonstrate that, whether in the condensation reaction or cycloaddition, the reaction proceeds through the atomic centers with the most important Fukui functions, which is in full agreement with experimental observations. In the condensation reaction, thermodynamic control of regio, chemo, and stereoselectivity is observed, while those of cycloaddition are subject to kinetic control. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=cycloaddition%20reaction" title="cycloaddition reaction">cycloaddition reaction</a>, <a href="https://publications.waset.org/abstracts/search?q=regioselectivity" title=" regioselectivity"> regioselectivity</a>, <a href="https://publications.waset.org/abstracts/search?q=mechanism%20reaction" title=" mechanism reaction"> mechanism reaction</a>, <a href="https://publications.waset.org/abstracts/search?q=NMR%20analysis" title=" NMR analysis"> NMR analysis</a> </p> <a href="https://publications.waset.org/abstracts/192375/synthesis-characterization-and-quantum-investigations-on-32-cycloaddition-reaction-of-nitrile-oxide-with-15-benzodiazepine" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/192375.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">17</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">5</span> Synthesis, Density Functional Theory (DFT) and Antibacterial Studies of Highly Functionalized Novel Spiropyrrolidine 4-Quinolone-3-Carboxylic Acids Derived from 6-Acetyl Quinolone</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Thangaraj%20Arasakumar">Thangaraj Arasakumar</a>, <a href="https://publications.waset.org/abstracts/search?q=Athar%20Ata"> Athar Ata</a>, <a href="https://publications.waset.org/abstracts/search?q=Palathurai%20Subramaniam%20Mohan"> Palathurai Subramaniam Mohan</a> </p> <p class="card-text"><strong>Abstract:</strong></p> A series of novel 4-quinolone-3-carboxylic acid grafted spiropyrrolidines as new type of antibacterial agents were synthesized via multicomponent 1,3-dipolar cycloaddition reaction of an azomethine ylides with a newly prepared (E)-4-oxo-6-(3-phenyl-acryloyl)-1,4-dihydro-quinoline-3-carboxylic acids in high regioselectivity with good yields. The structure of cycloadduct characterized by FT IR, mass, 1H, 13C, 2D NMR techniques and elemental analysis. Structure and spectrometry of compound 8a has been investigated theoretically by using HF and DFT approach at B3LYP, M05-2x/6-31G* levels of theories. The optimized geometries and calculated vibrational frequencies are evaluated via comparison with experimental values. A good agreement is found between the measured and calculated values. The DFT studies support the molecular mechanism of this cycloaddition reaction and determine the molecular electrostatic potential and thermodynamic properties. Furthermore, the antibacterial activities of synthesized compounds were evaluated against Gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis) and Gram-negative bacteria strains (Escherichia coli, Klebsiella pneumoniae). Among 21 compounds screened, 8f and 8p were found to be more active against tested bacteria. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=antibacterial%20activity" title="antibacterial activity">antibacterial activity</a>, <a href="https://publications.waset.org/abstracts/search?q=azomethine%20ylide" title=" azomethine ylide"> azomethine ylide</a>, <a href="https://publications.waset.org/abstracts/search?q=DFT%20calculation" title=" DFT calculation"> DFT calculation</a>, <a href="https://publications.waset.org/abstracts/search?q=spirooxindole" title=" spirooxindole"> spirooxindole</a> </p> <a href="https://publications.waset.org/abstracts/44428/synthesis-density-functional-theory-dft-and-antibacterial-studies-of-highly-functionalized-novel-spiropyrrolidine-4-quinolone-3-carboxylic-acids-derived-from-6-acetyl-quinolone" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/44428.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">215</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">4</span> Regioselective Nucleophilic Substitution of the Baylis-Hillman Adducts with Iodine</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Zahid%20Shafiq">Zahid Shafiq</a>, <a href="https://publications.waset.org/abstracts/search?q=Li%20Liu"> Li Liu</a>, <a href="https://publications.waset.org/abstracts/search?q=Dong%20Wang"> Dong Wang</a>, <a href="https://publications.waset.org/abstracts/search?q=Yong-Jun%20Chen"> Yong-Jun Chen</a> </p> <p class="card-text"><strong>Abstract:</strong></p> As synthetic organic methods are increasingly concerned with the growing importance of sustainable chemistry, iodine recently has emerged as an inexpensive, non-toxic, readily available and environmentally benign catalyst for various organic transformations to afford the corresponding products in high yields with high regio- and chemoselectivity. Iodine has found widespread applications in various organic synthesis such as Michael addition, coupling reaction and also in the multicomponent synthesis where it can efficiently activate C=C, C=O, C=N, and so forth. Iodine not only has been shown to be an efficient mild Lewis acid in various processes, but also due to its moderate nature, and water tolerance, reactions catalyzed by iodine can be effectively carried out in neutral media under very mild conditions. We have successfully described an efficient procedure for the nucleophilic substitution of the Baylis-Hillman (BH) adducts and their corresponding acetates with indoles to get α-substitution product using catalytic Silver Triflate (AgOTf) as Lewis acid. At this point, we were interested to develop an environmentally benign catalytic system to effect this substitution reaction and to avoid the use of metal Lewis acid as a catalyst. Since, we observed the formation of -product during the course of the reaction, we also became interested to explore the reaction conditions in order to control regioselectivity and to obtain both regioisomers. The developed methodology resulted in regioselective substitution products with controlled selectivity. Further, the substitution products were used to synthesize various Tri- and Tetracyclo Azepino indole derivatives via reductive amination. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=indole" title="indole">indole</a>, <a href="https://publications.waset.org/abstracts/search?q=regioselective" title=" regioselective"> regioselective</a>, <a href="https://publications.waset.org/abstracts/search?q=Baylis-Hillman" title=" Baylis-Hillman"> Baylis-Hillman</a>, <a href="https://publications.waset.org/abstracts/search?q=substitution" title=" substitution"> substitution</a> </p> <a href="https://publications.waset.org/abstracts/110900/regioselective-nucleophilic-substitution-of-the-baylis-hillman-adducts-with-iodine" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/110900.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">196</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">3</span> Molecular Electron Density Theory Study on the Mechanism and Selectivity of the 1,3 Dipolar Cycloaddition Reaction of N-Methyl-C-(2-Furyl) Nitrone with Activated Alkenes</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Moulay%20Driss%20Mellaoui">Moulay Driss Mellaoui</a>, <a href="https://publications.waset.org/abstracts/search?q=Abdallah%20Imjjad"> Abdallah Imjjad</a>, <a href="https://publications.waset.org/abstracts/search?q=Rachid%20Boutiddar"> Rachid Boutiddar</a>, <a href="https://publications.waset.org/abstracts/search?q=Haydar%20Mohammad-Salim"> Haydar Mohammad-Salim</a>, <a href="https://publications.waset.org/abstracts/search?q=Nivedita%20Acharjee"> Nivedita Acharjee</a>, <a href="https://publications.waset.org/abstracts/search?q=Hassan%20Bourzi"> Hassan Bourzi</a>, <a href="https://publications.waset.org/abstracts/search?q=Souad%20El%20Issami"> Souad El Issami</a>, <a href="https://publications.waset.org/abstracts/search?q=Khalid%20Abbiche"> Khalid Abbiche</a>, <a href="https://publications.waset.org/abstracts/search?q=Hanane%20Zejli"> Hanane Zejli</a> </p> <p class="card-text"><strong>Abstract:</strong></p> We have investigated the underlying molecular processes involved in the [3+2] cycloaddition (32CA) reactions between N-methyl-C-(2-furyl) nitrone and three acetylene derivatives: 4b, 5b, and 6b. For this investigation, we utilized molecular electron density theory (MEDT) and density functional theory (DFT) methods at the B3LYP-D3/6 31G (d) computational level. These 32CA reactions, which exhibit a zwitterionic (zw-type) nature, proceed through a one-step mechanism with activation enthalpies ranging from 8.80 to 14.37 kcal mol−1 in acetonitrile and ethanol solvents. When the nitrone reacts with phenyl methyl propiolate (4b), two regioisomeric pathways lead to the formation of two products: P1,5-4b and P1,4-4b. On the other hand, when the nitrone reacts with dimethyl acetylene dicarboxylate (5b) and acetylene dicarboxylic acid (but-2-ynedioic acid) (6b), it results in the formation of a single product. Through topological analysis, we can categorize the nitrone as a zwitterionic three-atom component (TAC). Furthermore, the analysis of conceptual density functional theory (CDFT) indices classifies the 32CA reactions of the nitrone with 4b, 5b, and 6b as forward electron density flux (FEDF) reactions. The study of bond evolution theory (BET) reveals that the formation of new C-C and C-O covalent bonds does not initiate in the transition states, as the intermediate stages of these reactions display pseudoradical centers of the atoms already involved in bonding. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=4-isoxazoline" title="4-isoxazoline">4-isoxazoline</a>, <a href="https://publications.waset.org/abstracts/search?q=DFT%2FB3LYP-D3" title=" DFT/B3LYP-D3"> DFT/B3LYP-D3</a>, <a href="https://publications.waset.org/abstracts/search?q=regioselectivity" title=" regioselectivity"> regioselectivity</a>, <a href="https://publications.waset.org/abstracts/search?q=cycloaddition%20reaction" title=" cycloaddition reaction"> cycloaddition reaction</a>, <a href="https://publications.waset.org/abstracts/search?q=MEDT" title=" MEDT"> MEDT</a>, <a href="https://publications.waset.org/abstracts/search?q=ELF" title=" ELF"> ELF</a> </p> <a href="https://publications.waset.org/abstracts/167271/molecular-electron-density-theory-study-on-the-mechanism-and-selectivity-of-the-13-dipolar-cycloaddition-reaction-of-n-methyl-c-2-furyl-nitrone-with-activated-alkenes" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/167271.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">183</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">2</span> Chiral Amine Synthesis and Recovery by Using High Molecular Weight Amine Donors</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Claudia%20Matassa">Claudia Matassa</a>, <a href="https://publications.waset.org/abstracts/search?q=Matthias%20Hohne"> Matthias Hohne</a>, <a href="https://publications.waset.org/abstracts/search?q=Dominic%20Ormerod"> Dominic Ormerod</a>, <a href="https://publications.waset.org/abstracts/search?q=Yamini%20Satyawali"> Yamini Satyawali</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Chiral amines integrate the backbone of several active pharmaceutical ingredients (APIs) used in modern medicine for the treatment of a vast range of diseases. Despite the demand, their synthesis remains challenging. Besides a range of chemicals and enzymatical methods, chiral amine synthesis using transaminases (EC 2.6.1.W) represents a useful alternative to access this important class of compounds. Even though transaminases exhibit excellent stereo and regioselectivity and the potential for high yield, the reaction suffers from a number of challenges, including the thermodynamic equilibrium, product inhibition, and low substrate solubility. In this work, we demonstrate a membrane assisted strategy for addressing these challenges. It involves the use of high molecular weight (HMW) amine donors for the transaminase-catalyzed synthesis of 4-phenyl-2-butylamine in both aqueous and organic solvent media. In contrast to common amine donors such as alanine or isopropylamine, these large molecules, provided in excess for thermodynamic equilibrium shifting, are easily retained by commercial nanofiltration membranes; thus a selective permeation of the desired smaller product amine is possible. The enzymatic transamination in aqueous media, combined with selective product removal shifted the equilibrium enhancing substrate conversion by an additional 25% compared to the control reaction. Along with very efficient amine product removal, there was undesirable loss of ketone substrate and low product concentration was achieved. The system was therefore further improved by performing the reaction in organic solvent (n-heptane). Coupling the reaction system with membrane-assisted product removal resulted in a highly concentrated and relatively pure ( > 97%) product solution. Moreover, a product yield of 60% was reached, compared to 15% without product removal. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=amine%20donor" title="amine donor">amine donor</a>, <a href="https://publications.waset.org/abstracts/search?q=chiral%20amines" title=" chiral amines"> chiral amines</a>, <a href="https://publications.waset.org/abstracts/search?q=in%20situ%20product%20removal" title=" in situ product removal"> in situ product removal</a>, <a href="https://publications.waset.org/abstracts/search?q=transamination" title=" transamination"> transamination</a> </p> <a href="https://publications.waset.org/abstracts/110355/chiral-amine-synthesis-and-recovery-by-using-high-molecular-weight-amine-donors" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/110355.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">154</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">1</span> Allylation of Active Methylene Compounds with Cyclic Baylis-Hillman Alcohols: Why Is It Direct and Not Conjugate?</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Karim%20Hrratha">Karim Hrratha</a>, <a href="https://publications.waset.org/abstracts/search?q=Khaled%20Essalahb"> Khaled Essalahb</a>, <a href="https://publications.waset.org/abstracts/search?q=Christophe%20Morellc"> Christophe Morellc</a>, <a href="https://publications.waset.org/abstracts/search?q=Henry%20Chermettec"> Henry Chermettec</a>, <a href="https://publications.waset.org/abstracts/search?q=Salima%20Boughdiria"> Salima Boughdiria </a> </p> <p class="card-text"><strong>Abstract:</strong></p> Among the carbon-carbon bond formation types, allylation of active methylene compounds with cyclic Baylis-Hillman (BH) alcohols is a reliable and widely used method. This reaction is a very attractive tool in organic synthesis of biological and biodiesel compounds. Thus, in view of an insistent and peremptory request for an efficient and straightly method for synthesizing the desired product, a thorough analysis of various aspects of the reaction processes is an important task. The product afforded by the reaction of active methylene with BH alcohols depends largely on the experimental conditions, notably on the catalyst properties. All experiments reported that catalysis is needed for this reaction type because of the poor ability of alcohol hydroxyl group to be as a suitable leaving group. Within the catalysts, several transition- metal based have been used such as palladium in the presence of acid or base and have been considered as reliable methods. Furthemore, acid catalysts such as BF3.OEt2, BiX3 (X= Cl, Br, I, (OTf)3), InCl3, Yb(OTf)3, FeCl3, p-TsOH and H-montmorillonite have been employed to activate the C-C bond formation through the alkylation of active methylene compounds. Interestingly a report of a smoothly process for the ability of 4-imethyaminopyridine(DMAP) to catalyze the allylation reaction of active methylene compounds with cyclic Baylis-Hillman (BH) alcohol appeared recently. However, the reaction mechanism remains ambiguous, since the C- allylation process leads to an unexpected product (noted P1), corresponding to a direct allylation instead of conjugate allylation, which involves the most electrophilic center according to the electron withdrawing group CO effect. The main objective of the present theoretical study is to better understand the role of the DMAP catalytic activity as well as the process leading to the end- product (P1) for the catalytic reaction of a cyclic BH alcohol with active methylene compounds. For that purpose, we have carried out computations of a set of active methylene compounds varying by R1 and R2 toward the same alcohol, and we have attempted to rationalize the mechanisms thanks to the acid–base approach, and conceptual DFT tools such as chemical potential, hardness, Fukui functions, electrophilicity index and dual descriptor, as these approaches have shown a good prediction of reactions products.The present work is then organized as follows: In a first part some computational details will be given, introducing the reactivity indexes used in the present work, then Section 3 is dedicated to the discussion of the prediction of the selectivity and regioselectivity. The paper ends with some concluding remarks. In this work, we have shown, through DFT method at the B3LYP/6-311++G(d,p) level of theory that: The allylation of active methylene compounds with cyclic BH alcohol is governed by orbital control character. Hence the end- product denoted P1 is generated by direct allylation. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=DFT%20calculation" title="DFT calculation">DFT calculation</a>, <a href="https://publications.waset.org/abstracts/search?q=gas%20phase%20pKa" title=" gas phase pKa"> gas phase pKa</a>, <a href="https://publications.waset.org/abstracts/search?q=theoretical%20mechanism" title=" theoretical mechanism"> theoretical mechanism</a>, <a href="https://publications.waset.org/abstracts/search?q=orbital%20control" title=" orbital control"> orbital control</a>, <a href="https://publications.waset.org/abstracts/search?q=charge%20control" title=" charge control"> charge control</a>, <a href="https://publications.waset.org/abstracts/search?q=Fukui%20function" title=" Fukui function"> Fukui function</a>, <a href="https://publications.waset.org/abstracts/search?q=transition%20state" title=" transition state"> transition state</a> </p> <a href="https://publications.waset.org/abstracts/27600/allylation-of-active-methylene-compounds-with-cyclic-baylis-hillman-alcohols-why-is-it-direct-and-not-conjugate" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/27600.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">306</span> </span> </div> </div> </div> </main> <footer> <div id="infolinks" class="pt-3 pb-2"> <div class="container"> <div style="background-color:#f5f5f5;" class="p-3"> <div class="row"> <div class="col-md-2"> <ul class="list-unstyled"> About <li><a href="https://waset.org/page/support">About Us</a></li> <li><a href="https://waset.org/page/support#legal-information">Legal</a></li> <li><a target="_blank" rel="nofollow" href="https://publications.waset.org/static/files/WASET-16th-foundational-anniversary.pdf">WASET celebrates its 16th foundational anniversary</a></li> </ul> </div> <div class="col-md-2"> <ul class="list-unstyled"> Account <li><a href="https://waset.org/profile">My Account</a></li> </ul> </div> <div class="col-md-2"> <ul class="list-unstyled"> Explore <li><a href="https://waset.org/disciplines">Disciplines</a></li> <li><a href="https://waset.org/conferences">Conferences</a></li> <li><a href="https://waset.org/conference-programs">Conference Program</a></li> <li><a href="https://waset.org/committees">Committees</a></li> <li><a href="https://publications.waset.org">Publications</a></li> </ul> </div> <div class="col-md-2"> <ul class="list-unstyled"> Research <li><a href="https://publications.waset.org/abstracts">Abstracts</a></li> <li><a href="https://publications.waset.org">Periodicals</a></li> <li><a href="https://publications.waset.org/archive">Archive</a></li> </ul> </div> <div class="col-md-2"> <ul class="list-unstyled"> Open Science <li><a target="_blank" rel="nofollow" href="https://publications.waset.org/static/files/Open-Science-Philosophy.pdf">Open Science Philosophy</a></li> <li><a target="_blank" rel="nofollow" href="https://publications.waset.org/static/files/Open-Science-Award.pdf">Open Science Award</a></li> <li><a target="_blank" rel="nofollow" href="https://publications.waset.org/static/files/Open-Society-Open-Science-and-Open-Innovation.pdf">Open Innovation</a></li> <li><a target="_blank" rel="nofollow" href="https://publications.waset.org/static/files/Postdoctoral-Fellowship-Award.pdf">Postdoctoral Fellowship Award</a></li> <li><a target="_blank" rel="nofollow" href="https://publications.waset.org/static/files/Scholarly-Research-Review.pdf">Scholarly Research Review</a></li> </ul> </div> <div class="col-md-2"> <ul class="list-unstyled"> Support <li><a href="https://waset.org/page/support">Support</a></li> <li><a href="https://waset.org/profile/messages/create">Contact Us</a></li> <li><a href="https://waset.org/profile/messages/create">Report Abuse</a></li> </ul> </div> </div> </div> </div> </div> <div class="container text-center"> <hr style="margin-top:0;margin-bottom:.3rem;"> <a href="https://creativecommons.org/licenses/by/4.0/" target="_blank" class="text-muted small">Creative Commons Attribution 4.0 International License</a> <div id="copy" class="mt-2">© 2024 World Academy of Science, Engineering and Technology</div> </div> </footer> <a href="javascript:" id="return-to-top"><i class="fas fa-arrow-up"></i></a> <div class="modal" id="modal-template"> <div class="modal-dialog"> <div class="modal-content"> <div class="row m-0 mt-1"> <div class="col-md-12"> <button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">×</span></button> </div> </div> <div class="modal-body"></div> </div> </div> </div> <script src="https://cdn.waset.org/static/plugins/jquery-3.3.1.min.js"></script> <script src="https://cdn.waset.org/static/plugins/bootstrap-4.2.1/js/bootstrap.bundle.min.js"></script> <script src="https://cdn.waset.org/static/js/site.js?v=150220211556"></script> <script> jQuery(document).ready(function() { /*jQuery.get("https://publications.waset.org/xhr/user-menu", function (response) { jQuery('#mainNavMenu').append(response); });*/ jQuery.get({ url: "https://publications.waset.org/xhr/user-menu", cache: false }).then(function(response){ jQuery('#mainNavMenu').append(response); }); }); </script> </body> </html>