1
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Diastereo- and Enantioselective Synthesis of Highly Functionalized Tetrahydropyridines by Recyclable Novel Bifunctional C2-Symmetric Ionic Liquid–Supported (S)-Proline Organocatalyst. Catalysts 2023. [DOI: 10.3390/catal13010209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
An efficient, novel bifunctional C2-symmetric ionic liquid–supported (S)-proline organocatalyst 7 was developed for a one-pot, five-component reaction involving β-keto esters 8, aryl aldehydes 9, and aryl amines 10, affording highly functionalized tetrahydropyridines 11a–o by simultaneous generation of fives bonds and two stereogenic centers with extraordinary diastereo- and enantioselectivities (up to >99:1 dr, 95:5 er) in isopropanol with high yields (up to 92%). This protocol provides quick access to diverse enantio-enriched, highly functionalized diastereo- and enantioselective tetrahydropyridines in a green medium without any column chromatographic purification. The catalyst was recycled five times without significant loss of its catalytic activity.
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2
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Chudasama SJ, Shah BJ, Patel KM, Dhameliya TM. The spotlight review on ionic liquids catalyzed synthesis of aza- and oxa-heterocycles reported in 2021. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.119664] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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3
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Dhameliya TM, Nagar PR, Bhakhar KA, Jivani HR, Shah BJ, Patel KM, Patel VS, Soni AH, Joshi LP, Gajjar ND. Recent advancements in applications of ionic liquids in synthetic construction of heterocyclic scaffolds: A spotlight. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2021.118329] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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4
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Schulze JS, Brand RD, Hering JG, Riegger LM, Schreiner PR, Smarsly BM. DMAP immobilized on porous silica particles and monoliths for the esterification of phenylethanol in continuous flow. ChemCatChem 2022. [DOI: 10.1002/cctc.202101845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Julia S. Schulze
- Justus Liebig Universitat Giessen Institute of Physical Chemistry 35392 Giessen GERMANY
| | - Raoul D. Brand
- Justus Liebig Universitat Giessen Institute of Physical Chemistry 35392 Giessen GERMANY
| | | | - Luise M. Riegger
- Justus Liebig Universitat Giessen Institute of Physical Chemistry 35392 Giessen GERMANY
| | - Peter R. Schreiner
- Justus Liebig Universitat Giessen Institute of Organic Chemistry 35392 Giessen GERMANY
| | - Bernd M. Smarsly
- Physikalisch-Chemisches Institut Justus-Liebig-Universität Gießen Heinrich Buff Ring 17 35392 Gießen GERMANY
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5
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Omosun NN, Smith GS. Monometallic and bimetallic sulfonated Rh(I) complexes: Synthesis and evaluation as recyclable hydroformylation catalysts. J Organomet Chem 2021. [DOI: 10.1016/j.jorganchem.2021.122022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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6
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Juaristi E. Recent developments in next generation (S)-proline-derived chiral organocatalysts. Tetrahedron 2021. [DOI: 10.1016/j.tet.2021.132143] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
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7
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Bisogno FR, Fernández R, Lassaletta JM, de Gonzalo G. Room Temperature Ionic Liquids in Asymmetric Hetero-Ene Type Reactions: Improving Organocatalyst Performance at Lower Temperatures. Molecules 2021; 26:molecules26020355. [PMID: 33445529 PMCID: PMC7827838 DOI: 10.3390/molecules26020355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 12/30/2020] [Accepted: 01/08/2021] [Indexed: 11/25/2022] Open
Abstract
Room temperature ionic liquids (RTILs) have been widely used as (co)solvents in several catalytic processes modifying, in most of the cases, the catalyst activity and/or the selectivity for the studied reactions. However, there are just a few examples of their use in hydrogen bonding organocatalysis. In this paper, we show the positive effect of a set of imidazole-based ionic liquids ([bmim]BF4 and [hmim]PF6) in the enantioselective addition of formaldehyde tert-butylhydrazone to prochiral α-keto esters catalyzed by a sugar-based chiral thiourea. Reactions performed in the presence of low percentages of RTILs led to an increase of the catalyst activity, thereby making possible to work at lower temperatures. Thus, the chiral tert-butyl azomethyl tertiary alcohols could be obtained with moderate to good conversions and higher enantioselectivities for most of the studied substrates when using up to 30 vol% of [hmim]PF6 as a cosolvent in processes performed in toluene.
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Affiliation(s)
- Fabricio R. Bisogno
- Facultad de Ciencias Químicas, Instituto de Investigaciones en Físico-Química de Córdoba, Universidad Nacional de Córdoba, (INFIQC, CONICET-UNC), Haya de la Torre y Medina Allende, Ciudad Universitaria, Córdoba 5000, Argentina;
| | - Rosario Fernández
- Departamento de Química Orgánica, Universidad de Sevilla, c/Profesor García González 1, 41012 Sevilla, Spain;
| | - Jose María Lassaletta
- Instituto de Investigaciones Químicas (CSIC-US) and Centro de Innovación en Química Avanzada (ORFEO-CINQA), Avda. Américo Vespucio 49, 41092 Sevilla, Spain;
| | - Gonzalo de Gonzalo
- Departamento de Química Orgánica, Universidad de Sevilla, c/Profesor García González 1, 41012 Sevilla, Spain;
- Correspondence: ; Tel.: +34-954-559997
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8
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Bifunctional C2-symmetric ionic liquid-supported (S)-proline as a recyclable organocatalyst for Mannich reactions in neat condition. RESULTS IN CHEMISTRY 2021. [DOI: 10.1016/j.rechem.2021.100152] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
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9
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Krištofíková D, Modrocká V, Mečiarová M, Šebesta R. Green Asymmetric Organocatalysis. CHEMSUSCHEM 2020; 13:2828-2858. [PMID: 32141177 DOI: 10.1002/cssc.202000137] [Citation(s) in RCA: 70] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 03/05/2020] [Indexed: 06/10/2023]
Abstract
Asymmetric organocatalysis is becoming one of the main tools for the synthesis of chiral compounds that are needed as medicines, crop protection agents, and other bioactive molecules. It can be effectively combined with various green chemistry methodologies. Intensification techniques, such as ball milling, flow, high pressure, or light, bring not only higher yields, faster reactions, and easier product isolation, but also new reactivities. More sustainable reaction media, such as ionic liquids, deep eutectic solvents, green solvent alternatives, and water, also considerably enhance the sustainability profile of many organocatalytic reactions.
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Affiliation(s)
- Dominika Krištofíková
- Department of Organic Chemistry, Faculty of Natural Sciences, Comenius University in Bratislava, Mlynska dolina, Ilkovicova 6, 842 15, Bratislava, Slovakia
| | - Viktória Modrocká
- Department of Organic Chemistry, Faculty of Natural Sciences, Comenius University in Bratislava, Mlynska dolina, Ilkovicova 6, 842 15, Bratislava, Slovakia
| | - Mária Mečiarová
- Department of Organic Chemistry, Faculty of Natural Sciences, Comenius University in Bratislava, Mlynska dolina, Ilkovicova 6, 842 15, Bratislava, Slovakia
| | - Radovan Šebesta
- Department of Organic Chemistry, Faculty of Natural Sciences, Comenius University in Bratislava, Mlynska dolina, Ilkovicova 6, 842 15, Bratislava, Slovakia
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10
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Prabhakara MD, Maiti B. Ionic liquid-immobilized proline(s) organocatalyst-catalyzed one-pot multi-component Mannich reaction under solvent-free condition. RESEARCH ON CHEMICAL INTERMEDIATES 2020. [DOI: 10.1007/s11164-020-04096-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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11
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Preparation and Application of a New Supported Nicotine-Based Organocatalyst for Synthesis of Various 1,5-Benzodiazepines. Catal Letters 2019. [DOI: 10.1007/s10562-019-02668-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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12
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Franconetti A, de Gonzalo G. Recent Developments on Supported Hydrogen-bond Organocatalysts. ChemCatChem 2018. [DOI: 10.1002/cctc.201801459] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Antonio Franconetti
- Departamento de Química; Universitat Autonoma de Barcelona; Cerdanyola del Vallés 01893 Spain
| | - Gonzalo de Gonzalo
- Departamento de Química Orgánica; Universidad de Sevilla; c/ Profesor García González 2 41012 Sevilla Spain
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13
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Cruz H, Servín FA, Madrigal D, Chávez D, Perez-Sicairos S, Aguirre G, Cooksy AL, Somanathan R. C 2 -symmetric sulfonamides as homogeneous and heterogeneous organocatalysts that mimic enzymes in enantioselective Michael additions. Chirality 2018; 30:1036-1044. [PMID: 29873852 DOI: 10.1002/chir.22984] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Revised: 05/04/2018] [Accepted: 05/07/2018] [Indexed: 11/07/2022]
Abstract
Herein, we report the synthesis of C2 -symmetric sulfonamides as homogeneous and heterogeneous organocatalysts and their application in the enantioselective conjugate 1,4-Michael addition of carbonylic nucleophiles to β-nitrostyrene. Organocatalysts hydrogen bond to β-nitrostyrene and enamine in the transition state, mimicking an enzyme leading to final products in high yields (up to 98%) and good enantioselectivities (up to 96%). In addition, these results were supported by density functional calculations.
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Affiliation(s)
- Harold Cruz
- Centro de Graduados e Investigación en Química del Instituto Tecnológico de Tijuana, Tijuana, B.C., Mexico
| | - Felipe A Servín
- Centro de Graduados e Investigación en Química del Instituto Tecnológico de Tijuana, Tijuana, B.C., Mexico
| | - Domingo Madrigal
- Centro de Graduados e Investigación en Química del Instituto Tecnológico de Tijuana, Tijuana, B.C., Mexico
| | - Daniel Chávez
- Centro de Graduados e Investigación en Química del Instituto Tecnológico de Tijuana, Tijuana, B.C., Mexico
| | - Sergio Perez-Sicairos
- Centro de Graduados e Investigación en Química del Instituto Tecnológico de Tijuana, Tijuana, B.C., Mexico
| | - Gerardo Aguirre
- Centro de Graduados e Investigación en Química del Instituto Tecnológico de Tijuana, Tijuana, B.C., Mexico
| | - Andrew L Cooksy
- Department of Chemistry and Biochemistry, San Diego State University, San Diego, CA, USA
| | - Ratnasamy Somanathan
- Centro de Graduados e Investigación en Química del Instituto Tecnológico de Tijuana, Tijuana, B.C., Mexico
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14
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Krasovskiy VG, Glukhov LM, Chernikova EA, Kapustin GI, Gorbatsevich OB, Koroteev AA, Kustov LM. Dicationic polysiloxane ionic liquids. Russ Chem Bull 2017. [DOI: 10.1007/s11172-017-1884-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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15
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Magnetic nanoparticles grafted l-carnosine dipeptide: remarkable catalytic activity in water at room temperature. JOURNAL OF THE IRANIAN CHEMICAL SOCIETY 2017. [DOI: 10.1007/s13738-017-1157-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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16
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Obregón-Zúñiga A, Juaristi E. (2S,4R)-Hyp-(S)-Phe-OMe dipeptide supported on imidazolium tagged molecules as recoverable organocatalysts for asymmetric aldol reactions using water as reaction medium. Tetrahedron 2017. [DOI: 10.1016/j.tet.2017.07.037] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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17
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Tukhvatshin RS, Kucherenko AS, Nelyubina YV, Zlotin SG. Tertiary Amine-Derived Ionic Liquid-Supported Squaramide as a Recyclable Organocatalyst for Noncovalent “On Water” Catalysis. ACS Catal 2017. [DOI: 10.1021/acscatal.7b00562] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Rinat S. Tukhvatshin
- N.D. Zelinsky Institute
of Organic Chemistry, Russian Academy of Sciences, 47, Leninsky
Prospect, 119991 Moscow, Russia
| | - Alexander S. Kucherenko
- N.D. Zelinsky Institute
of Organic Chemistry, Russian Academy of Sciences, 47, Leninsky
Prospect, 119991 Moscow, Russia
| | - Yulia V. Nelyubina
- A.N. Nesmeyanov Institute
of Organoelement Compounds, Russian Academy of Sciences, 28, Vavilova
Street, 119991 Moscow, Russia
| | - Sergei G. Zlotin
- N.D. Zelinsky Institute
of Organic Chemistry, Russian Academy of Sciences, 47, Leninsky
Prospect, 119991 Moscow, Russia
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18
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Goodrich P, Nimal Gunaratne HQ, Hall L, Wang Y, Jin L, Muldoon MJ, Ribeiro APC, Pombeiro AJL, Pârvulescu VI, Davey P, Hardacre C. Using chiral ionic liquid additives to enhance asymmetric induction in a Diels–Alder reaction. Dalton Trans 2017; 46:1704-1713. [DOI: 10.1039/c6dt04572c] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A bis-oxazoline ligand has been complexed using Cu(ii) and Zn(ii) trifluoromethanesulfonate and a range of chiral ionic liquid (CIL) additives based on natural products were used as a co-catalyst for a Diels–Alder reaction.
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Affiliation(s)
- P. Goodrich
- School of Chemistry and Chemical Engineering/QUILL
- Queen's University
- Belfast
- UK
| | | | - L. Hall
- School of Chemistry and Chemical Engineering/QUILL
- Queen's University
- Belfast
- UK
| | - Y. Wang
- School of Chemistry and Chemical Engineering/QUILL
- Queen's University
- Belfast
- UK
| | - L. Jin
- School of Science
- China Pharmaceutical University
- Nanjing
- P. R. China
| | - M. J. Muldoon
- School of Chemistry and Chemical Engineering/QUILL
- Queen's University
- Belfast
- UK
| | - A. P. C. Ribeiro
- Centro de Química Estrutural
- Complexo I
- Instituto Superior Técnico
- Universidade de Lisboa
- 1049-001 Lisboa
| | - A. J. L. Pombeiro
- Centro de Química Estrutural
- Complexo I
- Instituto Superior Técnico
- Universidade de Lisboa
- 1049-001 Lisboa
| | - V. I. Pârvulescu
- University of Bucharest
- Department of Chemical Technology and Catalysis
- Bucharest 030016
- Romania
| | - P. Davey
- Givaudan
- Schweiz AG
- CH-8600 Dübendorf
- Switzerland
| | - C. Hardacre
- School of Chemistry and Chemical Engineering/QUILL
- Queen's University
- Belfast
- UK
- School of Chemical Engineering and Analytical Science
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19
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Singh A, Chopra HK. New benzimidazolium-based chiral ionic liquids: synthesis and application in enantioselective sodium borohydride reductions in water. ACTA ACUST UNITED AC 2016. [DOI: 10.1016/j.tetasy.2016.04.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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20
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Lou LL, Zhang J, Du H, Zhao B, Li S, Yu W, Yu K, Liu S. Cinchona-derived prolinamide in Brønsted acidic ionic liquids: A novel and recyclable catalytic system for asymmetric aldol reaction. Catal Today 2016. [DOI: 10.1016/j.cattod.2015.10.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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21
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Chacón G, Durand J, Favier I, Teuma E, Gomez M. Ionic liquids in catalysis: molecular and nanometric metal systems. FRENCH-UKRAINIAN JOURNAL OF CHEMISTRY 2016. [DOI: 10.17721/fujcv4i1p23-36] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The catalyst immobilization in a liquid phase represents an attractive means to preserve high activities and selectivities, also permitting an easy recycling. To attain this goal, organic products should be extracted in a simple way from the catalytic phase leading to metal-free target compounds; for this reason, ionic liquids exhibiting high affinity for metallic species and low affinity for low polar compounds, turn into a promising medium, in particular for the synthesis of fine chemicals. In the present Accounts, we illustrate this approach through our research involving both molecular organometallic compounds and metallic nanoparticles dispersed in an ionic liquid phase.
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22
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PEG1000-Based Dicationic Acidic Ionic Liquid Catalyzed One-Pot Synthesis of 4-Aryl-3-Methyl-1-Phenyl-1H-Benzo[h]pyrazolo [3,4-b]quinoline-5,10-Diones via Multicomponent Reactions. Catalysts 2015. [DOI: 10.3390/catal5041649] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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23
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Kochetkov SV, Kucherenko AS, Zlotin SG. Asymmetric aldol reactions in ketone/ketone systems catalyzed by ionic liquid-supported C2-symmetrical organocatalyst. MENDELEEV COMMUNICATIONS 2015. [DOI: 10.1016/j.mencom.2015.05.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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24
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Mahé O, Brière JF, Dez I. Chitosan: An Upgraded Polysaccharide Waste for Organocatalysis. European J Org Chem 2015. [DOI: 10.1002/ejoc.201403396] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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25
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Khalafi-Nezhad A, Nourisefat M, Panahi F. l-Cysteine functionalized magnetic nanoparticles (LCMNP): a novel magnetically separable organocatalyst for one-pot synthesis of 2-amino-4H-chromene-3-carbonitriles in water. Org Biomol Chem 2015; 13:7772-9. [DOI: 10.1039/c5ob01030f] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Magnetic nanoparticles were functionalized with l-cysteine using a new and efficient method and introduced as a novel magnetically separable organocatalyst.
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Affiliation(s)
| | - Maryam Nourisefat
- Department of Chemistry
- College of Sciences
- Shiraz University
- Shiraz
- Iran
| | - Farhad Panahi
- Department of Chemistry
- College of Sciences
- Shiraz University
- Shiraz
- Iran
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26
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Chen G, Kang S, Ma Q, Chen W, Tang Y. Chemical and thermal stability of N-heterocyclic ionic liquids in catalytic C-H activation reactions. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2014; 52:673-679. [PMID: 24942984 DOI: 10.1002/mrc.4096] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Revised: 05/20/2014] [Accepted: 05/23/2014] [Indexed: 06/03/2023]
Abstract
(1)H-NMR spectrum analyses are applied to study the chemical and thermal stability of selected N-heterocyclic ionic liquids within the reaction system that can highly efficiently activate a C-H bond of methane and convert it into the C-O bond in methanol. Our results indicate that under such reaction conditions involving using a powerful Pt-based catalyst and strong acidic solvent, the aromatic ring of an imidazolium cation becomes unstable generating an ammonium ion (NH(4)(+)). Our results also suggest that the instability of the imidazolium ring is more chemically (participation in reactions) than thermally based. Modifications of the aromatic ring structure such as pyrazolium and triazolium cations can increase the chemical/thermal stability of ionic liquids under these reaction conditions.
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Affiliation(s)
- Guanyi Chen
- School of Environment Science and Engineering, Tianjin University, Tianjin, 300072, China; State Key Laboratory of Engines, Tianjin University, Tianjin, 300072, China
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The use of supported acidic ionic liquids in organic synthesis. Molecules 2014; 19:8840-84. [PMID: 24972271 PMCID: PMC6271805 DOI: 10.3390/molecules19078840] [Citation(s) in RCA: 95] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Revised: 05/30/2014] [Accepted: 06/16/2014] [Indexed: 11/17/2022] Open
Abstract
Catalysts obtained by the immobilisation of acidic ionic liquids (ILs) on solid supports offer several advantages compared to the use of catalytically active ILs themselves. Immobilisation may result in an increase in the number of accessible active sites of the catalyst and a reduction of the amount of the IL required. The ionic liquid films on the carrier surfaces provide a homogeneous environment for catalytic reactions but the catalyst appears macroscopically as a dry solid, so it can simply be separated from the reaction mixture. As another advantage, it can easily be applied in a continuous fixed bed reactor. In the present review the main synthetic strategies towards the preparation of supported Lewis acidic and Brønsted acidic ILs are summarised. The most important characterisation methods and structural features of the supported ionic liquids are presented. Their efficiency in catalytic reactions is discussed with special emphasis on their recyclability.
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