1
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The full spectrum tuning of fluorescent molecules via a one-pot multicomponent reaction. Tetrahedron Lett 2023; 130:154748. [PMID: 38371912 PMCID: PMC10871707 DOI: 10.1016/j.tetlet.2023.154748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2024]
Abstract
Fluorogenic probes for imaging enable visualization and analysis of difficult-to-reach cells and organelles. However, there are limited efficient examples of tuning these fluorescent molecules to higher wavelengths. This is vital since different tissues are sensitive to varying wavelength emissions. To address this need, we report the discovery, tuning, structure-photophysical property relationships (SPPR), and time-dependent DFT (TD-DFT) computations of 400-700+ nm fluorescent pyrido[2',1':2,3]imidazo[4,5-c]isoquinolines and substituted imidazo[1,2-a]pyridin-3-amines. The syntheses involve the trimethylsilylcyanide (TMSCN) modified Groebke-Blackburn-Bienaymé (GBB) multicomponent reaction as well as the TMSCN modified GBB combined with subsequent condensation of an aldehyde, and Aza-Friedel-Crafts-Intramolecular Cyclization-Oxidation all in one pot. The SPPR reveals that electron-withdrawing strength in the para-position of the aminopyridine starting material has direct control over the absorption and fluorescence emission wavelengths of these molecules. The TD-DFT computations show the changes in the natural transition orbitals (NTOs) with differing substitutions to the parent molecule that dictate the observed excitations, emissions, and fluorescence intensities. These findings give insights and directions for tuning the fluorescent properties of these motifs for various uses as probes and imaging agents.
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2
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Synthetic Imidazopyridine-Based Derivatives as Potential Inhibitors against Multi-Drug Resistant Bacterial Infections: A Review. Antibiotics (Basel) 2022; 11:antibiotics11121680. [PMID: 36551338 PMCID: PMC9774741 DOI: 10.3390/antibiotics11121680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Revised: 11/15/2022] [Accepted: 11/19/2022] [Indexed: 11/24/2022] Open
Abstract
Fused pyridines are reported to display various pharmacological activities, such as antipyretic, analgesic, antiprotozoal, antibacterial, antitumor, antifungal, anti-inflammatory, and antiapoptotic. They are widely used in the field of medicinal chemistry. Imidazopyridines (IZPs) are crucial classes of fused heterocycles that are expansively reported on in the literature. Evidence suggests that IZPs, as fused scaffolds, possess more diverse profiles than individual imidazole and pyridine moieties. Bacterial infections and antibacterial resistance are ever-growing risks in the 21st century. Only one IZP, i.e., rifaximin, is available on the market as an antibiotic. In this review, the authors highlight strategies for preparing other IZPs. A particular focus is on the antibacterial profile and structure-activity relationship (SAR) of various synthesized IZP derivatives. This research provides a foundation for the tuning of available compounds to create novel, potent antibacterial agents with fewer side effects.
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3
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Design, synthesis, in vitro α-glucosidase inhibitory, antioxidant activity and molecular docking studies of novel pyridine linked imidazo[1,2-a]pyridine derivatives. J Mol Struct 2022. [DOI: 10.1016/j.molstruc.2022.134238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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4
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Structural Determinants for the Mode of Action of Imidazopyridine DS2 at δ-Containing γ-Aminobutyric Acid Type A Receptors. J Med Chem 2021; 64:4730-4743. [PMID: 33847501 DOI: 10.1021/acs.jmedchem.0c02163] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Despite the therapeutic relevance of δ-containing γ-aminobutyric acid type A receptors (GABAARs) and the need for δ-selective compounds, the structural determinants for the mode and molecular site of action of δ-selective positive allosteric modulator imidazo[1,2-a]pyridine DS2 remain elusive. To guide the quest for insight, we synthesized a series of DS2 analogues guided by a structural receptor model. Using a fluorescence-based fluorometric imaging plate reader membrane potential assay, we found that the δ-selectivity and the pharmacological profile are severely affected by substituents in the 5-position of the imidazopyridine core scaffold. Interestingly, the 5-methyl, 5-bromo, and 5-chloro DS2 analogues, 30, 35, and 36, were shown to be superior to DS2 at α4β1δ as mid-high nanomolar potency δ-selective allosteric modulators, displaying 6-16 times higher potency than DS2. Of these, 30 also displayed at least 60-fold selectivity for α4β1δ over α4β1γ2 receptor subtypes representing a potential tool for the selective characterization of δ-containing GABAARs in general.
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5
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Tandem Strecker/C(sp 3)–H amination reactions for the construction of cyanide-functionalized imidazo[1,5- a]pyridines with NH 4SCN as a cyanating agent. Org Chem Front 2021. [DOI: 10.1039/d1qo01060c] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
An I2O5-mediated multicomponent reaction that allows the single-step construction of cyano-functionalized imidazo[1,5-a]pyridines with molecular diversity was realized for the first time.
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6
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Novel approach in the synthesis of imidazo [1, 2‐
a
] pyridine from phenyl acrylic acids. J Heterocycl Chem 2020. [DOI: 10.1002/jhet.4026] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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7
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The Groebke-Blackburn-Bienaymé Reaction. EUROPEAN JOURNAL OF CHEMISTRY (PRINT) 2019; 2019:7007-7049. [PMID: 34012704 PMCID: PMC8130801 DOI: 10.1002/ejoc.201901124] [Citation(s) in RCA: 74] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Indexed: 12/23/2022]
Abstract
Imidazo[1,2-a]pyridine is a well-known scaffold in many marketed drugs, such as Zolpidem, Minodronic acid, Miroprofen and DS-1 and it also serves as a broadly applied pharmacophore in drug discovery. The scaffold revoked a wave of interest when Groebke, Blackburn and Bienaymé reported independently a new three component reaction resulting in compounds with the imidazo[1,2-a]-heterocycles as a core structure. During the course of two decades the Groebke Blackburn Bienaymé (GBB-3CR) reaction has emerged as a very important multicomponent reaction (MCR), resulting in over a hundred patents and a great number of publications in various fields of interest. Now two compounds derived from GBB-3CR chemistry received FDA approval. To celebrate the first 20 years of GBB-chemistry, we present an overview of the chemistry of the GBB-3CR, including an analysis of each of the three starting material classes, solvents and catalysts. Additionally, a list of patents and their applications and a more in-depth summary of the biological targets that were addressed, including structural biology analysis, is given.
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8
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Facile synthesis of 2-arylimidazo[1,2-a]pyridines catalysed by DBU in aqueous ethanol. Proc Math Phys Eng Sci 2019. [DOI: 10.1098/rspa.2019.0238] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
A facile protocol for the synthesis of 2-arylimidazo[1,2-a]pyridines was developed using two-component cyclization of substituted 2-aminopyridines and substituted phenacyl bromides in 65–94% yield. The reaction was DBU catalysed using green solvent, aqueous ethanol (1 : 1 v/v) at room temperature. The atom economy of the products was calculated to be 66.25–73.41%. The developed protocol successfully exhibits a broad substrate scope, less reaction time, high to moderate yield and multigram scale synthesis.
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9
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Catalytic application of new manganese Schiff-base complex immobilized on chitosan-coated magnetic nanoparticles for one-pot synthesis of 3-iminoaryl-imidazo[1,2-a]pyridines. Int J Biol Macromol 2019; 139:904-916. [DOI: 10.1016/j.ijbiomac.2019.08.054] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Revised: 07/29/2019] [Accepted: 08/06/2019] [Indexed: 12/28/2022]
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10
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Alumina-Supported Gold Nanoparticles as a Bifunctional Catalyst for the Synthesis of 2-Amino-3-arylimidazo[1,2- a]pyridines. ACS OMEGA 2018; 3:17947-17956. [PMID: 31458387 PMCID: PMC6643465 DOI: 10.1021/acsomega.8b03047] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Accepted: 12/06/2018] [Indexed: 05/31/2023]
Abstract
The bifunctional catalytic efficacy of alumina-supported gold nanoparticles (Au/Al2O3) was investigated for the synthesis of a series of 2-amino-3-aryl-imidazopyridines through the chemoselective reduction of the corresponding 2-nitro-3-aryl-imidazo[1,2-a]pyridines in high isolated yields. This highly efficient protocol was initially applied for the synthesis of 2-nitro-3-aryl imidazo[1,2-a]pyridines via the reaction between 2-aminopyridine and nitroalkenes catalyzed by the present catalytic system Au/Al2O3. Moreover, the heterogeneous surface γ-Al2O3 was also found to catalyze this pathway in a comparable manner. However, only Au/Al2O3 was further proved as the appropriate catalytic system for the selective transfer hydrogenation of the synthesized 2-nitro imidazopyridine derivatives into the corresponding 2-amino-3-aryl imidazo[1,2-a]pyridines using NaBH4 as a hydrogen-donor molecule. In addition, the one-pot two-step reaction between nitroalkenes and aminopyridines in the presence of Au/Al2O3-NaBH4 provided directly the fast and facile synthesis of 2-amino-3-aryl imidazopyridines, highlighting a useful synthetic application of the catalytic protocol.
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11
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Efficient Access to Imidazo[1,2- a]pyridines/pyrazines/pyrimidines via Catalyst-Free Annulation Reaction under Microwave Irradiation in Green Solvent. ACS COMBINATORIAL SCIENCE 2018; 20:164-171. [PMID: 29373013 DOI: 10.1021/acscombsci.7b00173] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
An expeditious catalyst-free heteroannulation reaction for imidazo[1,2- a]pyridines/pyrimidines/pyrazines was developed in green solvent under microwave irradiation. Using H2O-IPA as the reaction medium, various substituted 2-aminopyridines/pyrazines/pyrimidines underwent annulation reaction with α-bromoketones under microwave irradiation to provide the corresponding imidazo[1,2- a]pyridines/pyrimidines/pyrazines in excellent yields. The synthetic methodology appears to be very simple and superior to the already reported procedures with the high abundance of commercial reagents and great ability in expanding the molecular diversity. The present synthetic sequence is visualized as an environmentally benign process which allows the introduction of three points of structural diversity to expand chemical space with excellent purity and yields. The anti-inflammatory and antimicrobial activities of the derivatives were evaluated. Screening results uncovered three derivatives with strong inhibition of albumin denaturation and two derivatives were active on Proteus and Klebsiella bacteria. These positive bioassay results implied that the library of potential anti-inflammatory agents could be rapidly prepared in an ecofriendly manner, and provided new insights into drug discovery for medicinal chemists.
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12
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Strecker reaction and α-amino nitriles: Recent advances in their chemistry, synthesis, and biological properties. Tetrahedron 2018. [DOI: 10.1016/j.tet.2018.01.005] [Citation(s) in RCA: 95] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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13
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An Efficient One-Pot Synthesis of Chiral N-Protected 3-Substituted (Diketo)piperazines via Ugi-4CR/De-Boc/Cyclization Process. ChemistrySelect 2018. [DOI: 10.1002/slct.201702943] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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14
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Efficient one-pot synthesis of enantiomerically pure N-protected-α-substituted piperazines from readily available α-amino acids. NEW J CHEM 2018. [DOI: 10.1039/c7nj04039c] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A new pathway towards enantiomerically pure 3-substituted piperazines, bearing a benzyl protecting group, has been developed in good overall yields (83–92%), starting from commercially available N-protected amino acids.
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15
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An efficient RuCl 3 ·H 2 O/I 2 catalytic system: A facile access to 3-aroylimidazo[1,2- a ]pyridines from 2-aminopyridines and chalcones. JOURNAL OF SAUDI CHEMICAL SOCIETY 2018. [DOI: 10.1016/j.jscs.2017.07.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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16
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Abstract
2-Nitrobenzyl isocyanide is reported as a universal convertible isocyanide with extensive applicability in both Ugi four-component reaction (Ugi-4CR) and Ugi-tetrazole reaction. The cleavage of this isocyanide from 17 examples in both acidic and basic conditions is presented. Additionally, this isocyanide has various handling and synthetic advantages, as it is easy to prepare, odorless, stable, and easy to handle as a solid.
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17
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Synthesis of functionalyzed imidazo[1,2-a]pyridines via domino A3-coupling/cycloisomerization approach. Chem Heterocycl Compd (N Y) 2017. [DOI: 10.1007/s10593-017-2066-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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18
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Synthesis of fluorescent heterocycles via a Knoevenagel/[4 + 1]-cycloaddition cascade using acetyl cyanide. Org Biomol Chem 2017; 15:6076-6079. [DOI: 10.1039/c7ob01239j] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Acetyl cyanide is utilized to synthesize fluorescent indolizines, benzo[d]pyrrolo[2,1-b]thiazoles, and pyrrolo[1,2-a]pyrazines in a single step.
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19
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20
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Synthesis of Novel Imidazo[1,2‐
a
]pyridin‐2‐amines from Arylamines and Nitriles via Sequential Addition and I
2
/KI‐Mediated Oxidative Cyclization. Chemistry 2016; 22:7617-22. [DOI: 10.1002/chem.201600849] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Indexed: 12/18/2022]
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21
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Trityl Isocyanide as a Mechanistic Probe in Multicomponent Chemistry: Walking the Line between Ugi- and Strecker-type Reactions. Chemistry 2016; 22:7837-42. [DOI: 10.1002/chem.201600285] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Indexed: 11/09/2022]
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22
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Synthesis of novel imidazo[1,2-a]pyridine-4-hydroxy-2H-coumarins by Groebke–Blackburn–Bienaymé multicomponent reaction as potential NS5B inhibitors. Tetrahedron 2016. [DOI: 10.1016/j.tet.2016.01.023] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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23
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Isocyanide based [4+1] cycloaddition reactions: an indispensable tool in multi-component reactions (MCRs). Chem Commun (Camb) 2016; 52:6958-76. [DOI: 10.1039/c6cc01562j] [Citation(s) in RCA: 112] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The advent of cycloaddition reactions in the synthesis of heterocycles and their ever burgeoning applications in the fields of materials chemistry, catalysis and drugs have been a profound scientific development.
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24
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Synthesis, antimicrobial and antioxidant activities of imidazotriazoles and new multicomponent reaction toward 5-amino-1-phenyl[1,2,4]triazole derivatives. Med Chem Res 2015. [DOI: 10.1007/s00044-015-1322-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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25
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26
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Acetyl cyanide as a cyanide source in a tandem catalyst-free modified Groebke–Blackburn–Bienaymé [4+1]-cycloaddition-Strecker cascade. Tetrahedron Lett 2015. [DOI: 10.1016/j.tetlet.2014.12.127] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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27
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Abstract
Here we describe the various strategies for the synthesis of imidazo[1,2-a]pyridines.
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28
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Diversity-oriented synthesis of fused-imidazole derivatives via Groebke–Blackburn–Bienayme reaction: a review. Tetrahedron 2015. [DOI: 10.1016/j.tet.2014.10.032] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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29
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30
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Synthesis of diverse nitrogen-enriched heterocyclic scaffolds using a suite of tunable one-pot multicomponent reactions. J Org Chem 2014; 79:5153-62. [PMID: 24788091 PMCID: PMC4059217 DOI: 10.1021/jo500723d] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Indexed: 01/22/2023]
Abstract
Five elegant and switchable three-component reactions which enable access to a new series of nitrogen-containing heterocycles are reported. A novel one-step addition of an isocyanide to a hydrazine derived Schiff base affords unique six-membered pyridotriazine scaffolds (A and E). With slight modification of reaction conditions and replacement of the nucleophilic isocyanide moiety with different electrophiles (i.e., isocyanates, isothiocyanates, cyclic anhydrides, and acyl chlorides) five-membered triazolopyridine scaffolds (B, D, F, G) are generated in a single step. Furthermore, the use of phenyl hydrazine enables access to dihydroindazole-carboxamides, devoid of a bridge-head nitrogen (C). All protocols are robust and tolerate a diverse collection of reactants, and as such, it is expected that the new scaffolds and associated chemistry will garner high interest from medicinal chemists involved in either file enhancement or specific target-related drug discovery campaigns.
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31
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Synthesis of pyrido[2′,1′:2,3]imidazo[4,5-c]isoquinolines via a one-pot, three-component reaction. Tetrahedron Lett 2014. [DOI: 10.1016/j.tetlet.2014.01.139] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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32
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Synthesis of 2-Aminoquinoxalines via One-Pot Cyanide-Based Sequential Reaction under Aerobic Oxidation Conditions. J Org Chem 2014; 79:901-7. [DOI: 10.1021/jo4021908] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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33
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MCRs reshaped into a switchable microwave-assisted protocol toward 5-aminoimidazoles and dihydrotriazines. Tetrahedron 2014; 7:54-59. [PMID: 24535889 PMCID: PMC3925149 DOI: 10.1016/j.tet.2013.11.035] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A tunable microwave-assisted protocol for the synthesis of two biologically relevant families of heterocycles has been designed. Via a simple switch of reaction conditions, the same starting materials can be engaged in either an improved synthesis of the dihydrotriazine scaffold or a novel, first-in-class MCR to render the challenging 5-aminoimidazole nucleus in a single step. An additional first in class MCR is also reported utilizing guanidines to afford 2,5-aminoimidazoles.
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34
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BF3/MCM-41 as nano structured solid acid catalyst for the synthesis of 3-iminoaryl-imidazo[1,2-a]pyridines. Catal Sci Technol 2014. [DOI: 10.1039/c3cy00947e] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Multi-component reaction of various types of aldehydes, 2-aminopyridines and trimethylsilyl cyanide was carried out in the presence of MCM-41 supported boron trifluoride (BF3/MCM-41) as a nanostructured solid acid catalyst for the synthesis of 3-iminoaryl-imidazo[1,2-a]pyridine derivatives.
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35
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A remote-controlled adaptive medchem lab: an innovative approach to enable drug discovery in the 21st Century. Drug Discov Today 2013; 18:795-802. [DOI: 10.1016/j.drudis.2013.03.001] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Revised: 02/25/2013] [Accepted: 03/08/2013] [Indexed: 10/27/2022]
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36
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Preparation and characterization of polyaniline-1-hydroxyethane 1,1-diphosphonic acid salt and its application as a catalyst for the synthesis ofN-benzylidine-2-phenyl imidazo[1,2-a]pyridines. J Appl Polym Sci 2013. [DOI: 10.1002/app.39456] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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37
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38
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A chemoselective Ugi-type reaction in water using TMSCN as a functional isonitrile equivalent: generation of heteroaromatic molecular diversity. Org Biomol Chem 2012; 10:9271-7. [DOI: 10.1039/c2ob26733k] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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39
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Synthesis of [1,2,4,5]tetrazino[6′,1′:2,3]imidazo[4,5-c]isoquinolin-5-ones by microwave-assisted three-component reaction. Tetrahedron Lett 2011. [DOI: 10.1016/j.tetlet.2011.07.129] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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40
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Catalysis and Multi-Component Reactions. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2011. [DOI: 10.1007/978-1-4419-7270-5_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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41
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General Multicomponent Strategy for the Synthesis of 2-Amino-1,4-diazaheterocycles: Scope, Limitations, and Utility. European J Org Chem 2010. [DOI: 10.1002/ejoc.200901360] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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42
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Silica-sulfuric acid: a highly efficient catalyst for the synthesis of imidazo[1,2-a]pyridines using trimethysilyl cyanide or cyanohydrins. Tetrahedron Lett 2009. [DOI: 10.1016/j.tetlet.2009.05.080] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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43
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Controlled microwave heating in modern organic synthesis: highlights from the 2004–2008 literature. Mol Divers 2009; 13:71-193. [PMID: 19381851 DOI: 10.1007/s11030-009-9138-8] [Citation(s) in RCA: 292] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2009] [Accepted: 02/27/2009] [Indexed: 01/25/2023]
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44
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Beyond the Ugi reaction: less conventional interactions between isocyanides and iminium species. Tetrahedron 2009. [DOI: 10.1016/j.tet.2008.12.002] [Citation(s) in RCA: 181] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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45
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Emerging molecular diversity from the intra-molecular Ugi reaction: iterative efficiency in medicinal chemistry. Mol Divers 2009; 13:195-207. [PMID: 19205916 DOI: 10.1007/s11030-009-9111-6] [Citation(s) in RCA: 110] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2008] [Accepted: 01/09/2009] [Indexed: 10/21/2022]
Abstract
This review details a now established area within the isonitrile multi-component reaction (IMCR) field of study, namely employing bi-functional reagents in the Ugi reaction for the construction of screening sets with the additional element or even possibly 'metric' of enhanced 'iterative efficiency potential'. The concept of 'iterative efficiency' will be briefly introduced, coupled with discussion on new synthetic routes to select bi-functional IMCR precursors and their use in the generation of pharmacologically relevant 'molecular diversity'.
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A novel class of extended pi-conjugated systems: one-pot synthesis of bis-3-aminoimidazo[1,2-a]pyridines, pyrimidines and pyrazines. Mol Divers 2008; 13:269-74. [DOI: 10.1007/s11030-008-9101-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2008] [Accepted: 11/08/2008] [Indexed: 10/21/2022]
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Catalysis of Ugi Four Component Coupling Reactions by Rare Earth Metal Triflates. J Org Chem 2008; 73:5595-7. [DOI: 10.1021/jo800745a] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Emerging approaches for the syntheses of bicyclic imidazo[1,2-x]-heterocycles. Mol Divers 2008; 12:1-15. [PMID: 18409015 DOI: 10.1007/s11030-008-9072-1] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2007] [Accepted: 02/24/2008] [Indexed: 11/29/2022]
Abstract
Imidazo-[1,2-x]heterocycles are versatile building blocks for use in both a 'drug hunters' quest to discover new leads and a chemical biologists search for effective molecular tools in 'cell perturbation' studies. At the front end of the drug discovery flow chart, the last 5-10 years have witnessed the discovery of new high-throughput methodologies which very quickly have enabled access to virtual libraries of these chemo-types in the realm of 10(7) derivatives. Interestingly, these often neglected cores in patent cooperation treaty (PCT) applications appear in several highly effective marketed drugs, completing the medicinal chemists search for clinical success. Such rigid chemo-types, all containing a bridgehead nitrogen atom, are thus poised for an ever increasing impact on the discovery and development of new molecular therapeutics. The following mini-review will briefly cover therapeutic utility, chemical methodologies and automation developed to enable preparation of arrays of these chemo-types in a high-throughput manner. Synthetic emphasis is placed on a 3-component-3-center isocyanide based multi-component reaction (IMCR), which spans solution, solid phase, flourous and microwave assisted organic synthesis.
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Ionic Liquid Promoted One-Pot Three-Component Reaction: Synthesis of Annulated Imidazo[1,2-a]azines Using Trimethylsilylcyanide. MONATSHEFTE FUR CHEMIE 2006. [DOI: 10.1007/s00706-006-0567-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Synthesis of fused imidazo-pyridine and -azepine derivatives by sequential van Leusen/Heck reactions. Tetrahedron Lett 2006. [DOI: 10.1016/j.tetlet.2006.03.056] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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