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HFIP-mediated C-3-alkylation of indoles and synthesis of indolo[2,3- b]quinolines & related natural products. Org Biomol Chem 2024; 22:3502-3509. [PMID: 38618907 DOI: 10.1039/d4ob00414k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/16/2024]
Abstract
An expeditious metal free C-3 alkylation of indoles and its NIS-mediated deviation to indolo[2,3-b]quinolines is reported. This protocol, executed in aqueous HFIP has broad substrate scope and is well inclined towards the ideas of sustainable chemistry. Applications of these strategies in accessing bioactive natural products like vibrindole, norcryptotakeine, neocryptolepine and indenoindolone scaffolds has also been demonstrated.
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2
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A Two-Step Synthesis of Unprotected 3-Aminoindoles via Post Functionalization with Nitrostyrene. Molecules 2023; 28:molecules28093657. [PMID: 37175067 PMCID: PMC10180116 DOI: 10.3390/molecules28093657] [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] [Received: 03/30/2023] [Revised: 04/19/2023] [Accepted: 04/21/2023] [Indexed: 05/15/2023] Open
Abstract
A novel, low-cost method for the preparation of not easily accessible free 3-aminoindoles has been developed. This approach is based on a well-established reaction between indoles and nitrostyrene in the presence of phosphorous acid, which results in the formation of 4'-phenyl-4'H-spiro[indole-3,5'-isoxazoles]. The latter could be transformed to corresponding aminated indoles by reaction with hydrazine hydrate in good or excellent yields upon microwave-assisted heating.
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3
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Solvent-controlled photosensitized divergent C3-ethoxycarbonylmethylation/hydroxyalkylation of imidazo[1,2-a]pyridines with diethyl bromomalonate. Tetrahedron 2022. [DOI: 10.1016/j.tet.2022.132988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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4
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Enantioselective Synthesis of δ-Carbolinones via N-Heterocyclic Carbene Catalysis. J Org Chem 2022; 87:10441-10448. [PMID: 35819024 DOI: 10.1021/acs.joc.2c00952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
An enantioselective synthesis of δ-carbolinones was accomplished through N-heterocyclic carbene-catalyzed formal [3+3] annulation of 3-aminoindoles with 2-bromoenals. This protocol offers a rapid and efficient synthetic approach for accessing a wide range of enantioenriched structurally interesting δ-carbolinones under mild reaction conditions.
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5
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Microwave‐Assisted Palladium‐catalyzed double C−H Activation: One‐pot Synthesis of Benzo[
a
]imidazo[5,1,2‐
cd
]indolizines from 2‐Phenylimidazo[1,2‐
a
]pyridines and 1,2‐Diiodobenzene. ChemistrySelect 2022. [DOI: 10.1002/slct.202201436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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6
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Base-promoted cascade β-F-elimination/electrocyclization/Diels–Alder/retro-Diels–Alder reaction: efficient access to δ-carboline derivatives. Chem Sci 2022; 13:10448-10454. [PMID: 36277643 PMCID: PMC9473522 DOI: 10.1039/d2sc03166c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2022] [Accepted: 08/13/2022] [Indexed: 11/30/2022] Open
Abstract
A serendipitous and highly efficient approach for the construction of a variety of δ-carboline derivatives was developed through base-promoted cascade β-F-elimination/electrocyclization/Diels–Alder/retro-Diels–Alder reaction of N-2,2,2-trifluoroethylisatin ketoimine esters with alkynes in good to high yields with excellent regio-/chemoselectivity control. Moreover, a reasonable reaction pathway was proposed, which was in accordance with the prepared reaction intermediate and control experiment results. The δ-carboline product could be easily converted into a new chiral Py-box-type ligand through simple synthetic transformations. This salient strategy featured the advantages of metal-free conditions, excellent regio-/chemoselectivity, good to high yields, and outstanding substrate tolerance. Importantly, the potential application of these fascinating δ-carboline derivative products is well demonstrated in the recognition of ferric ions. A serendipitous and efficient approach to access various δ-carbolines was developed through base-promoted cascade β-F-elimination/electrocyclization/Diels–Alder/retro-Diels–Alder reaction in good to high yields with excellent regio/chemoselectivity.![]()
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7
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Optical properties of natural small molecules and their applications in imaging and nanomedicine. Adv Drug Deliv Rev 2021; 179:113917. [PMID: 34384827 DOI: 10.1016/j.addr.2021.113917] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 07/31/2021] [Accepted: 08/05/2021] [Indexed: 01/10/2023]
Abstract
Natural small molecules derived from plants have fascinated scientists for centuries due to their practical applications in various fields, especially in nanomedicine. Some of the natural molecules were found to show intrinsic optical features such as fluorescence emission and photosensitization, which could be beneficial to provide spatial temporal information and help tracking the drugs in biological systems. Much efforts have been devoted to the investigation of optical properties and practical applications of natural molecules. In this review, optical properties of natural small molecules and their applications in fluorescence imaging, and theranostics will be summarized. First, we will introduce natural small molecules with different fluorescence emission, ranging from blue to near infrared emission. Second, imaging applications in biological samples will be covered. Third, we will discuss the applications of theranostic nanomedicines or drug delivering systems containing fluorescent natural molecules acting as imaging agents or photosensitizers. Finally, future perspectives in this field will be discussed.
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8
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Triflic acid-mediated N-heteroannulation of β-anilino-β-(methylthio)acrylonitriles: a facile synthesis of 4-amino-2-(methylthio)quinolines. Org Biomol Chem 2021; 19:8544-8553. [PMID: 34550145 DOI: 10.1039/d1ob01151k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Various functionalised 4-amino-2-(methylthio)quinolines are synthesised through triflic acid-mediated N-heteroannulation of α-functionalized-β-anilino-β-(methylthio)acrylonitriles for the first time. The N-heteroannulation process is highly chemoselective and has mild reaction conditions. However, this process fails in the absence of the β-methylthio group in the acrylonitriles. In addition, a new double N-heteroannulation process is demonstrated to synthesise indolo[3,2-c]quinolines from non-heterocyclic precursors. Natural product isocryptolepine is synthesised in four steps from an acyclic precursor.
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9
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Synthesis of Isocryptolepine-Triazole Adducts and Evaluation of Their Cytotoxic Activity. ChemMedChem 2021; 16:3750-3762. [PMID: 34610210 DOI: 10.1002/cmdc.202100554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 10/01/2021] [Indexed: 11/05/2022]
Abstract
Eighteen hybrid compounds between 8-bromo-2-fluoro-isocryptolepine (4) and 1,2,3-triazole were synthesized via azide rearrangement-annulation reaction. Compound 4 underwent regioselective N-propargylation and click reaction to form 8-bromo-2-fluoro-isocryptolepine-triazole hybrids 11 which were evaluated for cytotoxic activity. Compound 11 c containing 1-anisyltriazole was the most effective in inhibiting HepG2, HuCCA-1 and A549 cell lines (IC50 values of 1.65-3.07 μM) while compounds 11 a (1-phenyltriazole), 11 j (1-para-CF3 -benzyltriazole) and 11 l (1-meta-Cl-benzyltriazole) were potent inhibitors of HuCCA-1, HepG2 and A549 cell lines, respectively. Moreover, 11 l showed the lowest cytotoxicity to normal human kidney cell line. Compounds 11 c and 11 l provided improvement of cytotoxic activity over 4. Compounds 4, 11 c and 11 l were selected to investigate their mechanisms of action. The results showed that 4 could induce G2/M cell cycle arrest and was involved in the upregulation of p53 and p21 proteins. However, the mechanisms of growth inhibition by 11 c and 11 l were associated with G0/G1 cell cycle arrest and mediated by induction of oxidative stress.
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10
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Total Synthesis of Lamellarins G, J, L, and Z Using One-Pot Halogen Dance/Negishi Coupling. J Org Chem 2021; 86:13388-13401. [PMID: 34546054 DOI: 10.1021/acs.joc.1c01505] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A bottom-up synthesis of lamellarins G, J, L, and Z was achieved via one-pot halogen dance/Negishi coupling of a lithiated dibromopyrrole derivative. The easily accessible dibromopyrrole bearing an ester moiety underwent halogen dance smoothly at -78 °C within 10 min. The resultant α-pyrrolyllithium was transmetalated to the corresponding organozinc species, which was then coupled with an aryl iodide in the presence of catalytic palladium to provide the fully substituted pyrrole. Subsequent halogen-lithium exchange was performed to incorporate a boronate group exclusively at the β position proximal to the ester moiety. This synthetic intermediate allowed stepwise diarylation for the total synthesis of lamellarins G, J, L, and Z.
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11
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Modular Synthesis of Polysubstituted Quinolin-3-amines by Oxidative Cyclization of 2-(2-Isocyanophenyl)acetonitriles with Organoboron Reagents. Org Lett 2021; 23:6789-6794. [PMID: 34382811 DOI: 10.1021/acs.orglett.1c02373] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Polysubstituted quinolin-3-amines are vital structural motifs because of their broad biological activities as well as versatile transformational abilities. However, they are not easily accessible. We disclose a protocol with Mn(III) acetate as a mild one-electron oxidant promoting a radical process to construct polysubstituted quinolin-3-amines. 2-(2-Isocyanophenyl)acetonitriles and organoboron reagents are suitable substrates for this reaction. The remarkable advantages of this protocol are the practical method, mild approach, high reaction efficiency, and good compatibility of functional groups, providing straightforward access to functional quinoline derivatives.
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12
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Regioselective C-H arylation of imidazoles employing macrocyclic palladium(II) complex of organoselenium ligand. J Organomet Chem 2021. [DOI: 10.1016/j.jorganchem.2021.121907] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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13
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Pyrido[2',1':2,3]imidazo[4,5- c]isoquinolin-5-amines as Potential Cytotoxic Agents against Human Neuroblastoma. Pharmaceuticals (Basel) 2021; 14:ph14080750. [PMID: 34451847 PMCID: PMC8399734 DOI: 10.3390/ph14080750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 07/20/2021] [Accepted: 07/24/2021] [Indexed: 11/16/2022] Open
Abstract
We report herein the evaluation of various pyrido[2',1':2,3]imidazo[4,5-c]isoquinolin-5-amines as potential cytotoxic agents. These molecules were obtained by developing the multicomponent Groebke-Blackburn-Bienaymé reaction to yield various pyrido[2',1':2,3]imidazo[4,5-c]quinolines which are isosteres of ellipticine whose biological activities are well established. To evaluate the anticancer potential of these pyrido[2',1':2,3]imidazo[4,5-c]isoquinolin-5-amine derivatives in the human neuroblastoma cell line, the cytotoxicity was examined using the WST-1 assay after 72 h drug exposure. A clonogenic assay was used to assess the ability of treated cells to proliferate and form colonies. Protein expressions (Bax, bcl-2, cleaved caspase-3, cleaved PARP-1) were analyzed using Western blotting. The colony number decrease in cells was 50.54%, 37.88% and 27.12% following exposure to compounds 2d, 2g and 4b respectively at 10 μM. We also show that treating the neuroblastoma cell line with these compounds resulted in a significant alteration in caspase-3 and PARP-1 cleavage.
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14
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Synthesis of novel indolo[3,2-c]isoquinoline derivatives bearing pyrimidine, piperazine rings and their biological evaluation and docking studies against COVID-19 virus main protease. J Mol Struct 2021; 1229:129829. [PMID: 33390613 PMCID: PMC7767577 DOI: 10.1016/j.molstruc.2020.129829] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 12/05/2020] [Accepted: 12/21/2020] [Indexed: 12/19/2022]
Abstract
A series of hybrid indolo[3,2-c]isoquinoline (δ-carboline) analogs incorporating two pyrimidine and piperizine ring frameworks were synthesized. Intending biological activities and SAR we propose replacements of fluorine, methyl and methoxy of synthetic compounds for noteworthy antimicrobial, antioxidant, anticancer and anti-tuberculosis activities. Among these compounds 3a, 4a and 5e were progressively strong against E. coli and K. pneumonia. Whereas, compounds 4a, 5a and 6a with addition of various functional groups (OCH3, CH3) were excellent against S. aureus and B. subtilis. Compound 5c exhibited strong RSA and dynamic ferrous ion (Fe2+) metal chelating impact with IC50 of 7.88 ± 0.93 and 4.06 ± 0.31 µg/mL, respectively. Compound 5e was considerably cytotoxic against all cancer cells displaying activity better than the standard drug. Compounds 6b and 6e inhibited M. tuberculosis (MIC 1.0 mg/L) considerably. Molecular docking studies indicate that compounds 4d, 5a, 5b, 6b and 6f exhibited good interactions with 6LZE (COVID-19) and 6XFN (SARS-CoV-2) at active sites. The structure of the synthesized compounds were elementally analyzed using IR, 1H, 13C NMR and mass spectral information.
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15
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Iodothiophenes and Related Compounds as Coupling Partners in Copper-Mediated N-Arylation of Anilines. SYNTHESIS-STUTTGART 2021. [DOI: 10.1055/s-0040-1706542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Abstract
N-Arylation of various 2-acylated anilines with different electron-rich heteroaryl iodides (2- and 3-iodothiophenes, 2- and 3-iodobenzothiophenes, 2-iodobenzofuran) was achieved by using activated copper and potassium carbonate in dibutyl ether at reflux. The reactivity of the different heteroaryl iodides and anilines employed was discussed and rationalized on the basis of their electronic features. Subsequent cyclization by aromatic electrophilic substitution easily took place in the case of C2-free (benzo)thienyl or C3-free (benzo)furyl derivatives, affording original tri- and tetracycles. The antiproliferative activity of most of them was evaluated in A2058 melanoma cells and revealed four chlorinated tetracycles as effective growth inhibitors.
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Highly Selective Synthesis of 2-Substituted Pyrido[2,3- b]indole Derivatives Catalyzed by Iron Salts. CHINESE J ORG CHEM 2021. [DOI: 10.6023/cjoc202107028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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17
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Metal‐Free, H
2
O
2
‐Mediated, Regioselective Direct C‐3 Hydroxylation of Imidazo[1,2‐
a
]pyridines via C(sp
2
)‐H Bond Functionalization. ChemistrySelect 2020. [DOI: 10.1002/slct.202002219] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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18
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Abstract
A convergent total synthesis of lamellarins S and Z is described. The synthesis features a halogen dance of an easily accessible α,β-dibromopyrrole promoted by an ester moiety. The resultant β,β'-dibromopyrrole undergoes a ligand-controlled Suzuki-Miyaura coupling to provide a range of diarylated pyrrole derivatives. The established synthetic method was also applicable to the synthesis of ningalin B and lukianols A and B.
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Rh(III)-Catalyzed Tandem Acylmethylation/Nitroso Migration/Cyclization of N-Nitrosoanilines with Sulfoxonium Ylides in One Pot: Approach to 3-Nitrosoindoles. Org Lett 2020; 22:361-364. [DOI: 10.1021/acs.orglett.9b03768] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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20
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Experimental study of antiparkinsonian action of the harmine hydrochloride original compound. Pharmacol Rep 2019; 71:1050-1058. [PMID: 31605892 DOI: 10.1016/j.pharep.2019.06.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 04/26/2019] [Accepted: 06/05/2019] [Indexed: 11/27/2022]
Abstract
BACKGROUND The effects of chemical products on the nervous system have been studied by various scientists. In this work, the antiparkinsonian action of a water-soluble form of harmine hydrochloride was studied. The present studies aim to research antiparkinsonian action of the harmine hydrochloride original compound. METHODS To achieve the objective of the study, the authors used haloperidol-induced catalepsy and a method of Parkinson's syndrome (PS) induced by the MPTP (the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) neurotoxin. The experiments were performed on rats and mice which were divided into groups of 10 animals. RESULTS It was established that harmine hydrochloride (HH), at a certain dose, eliminated haloperidol-induced catalepsy in rats and reduced oligokinesia and rigidity in the parkinsonism test in mice. Seven days after the experiment, the authors found the presence of rigidity in animals which had received the neurotoxin. It manifested itself in a shortened stride length compared to this parameter in intact controls. CONCLUSIONS During the study the efficacy of harmine hydrochloride was equivalent to the effects of levodopa at a certain dose, which suggested that harmine hydrochloride compensated dopamine deficiency in the brain.
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Methods of synthesis of natural indoloquinolines isolated from Cryptolepis sanguinolenta. Chem Heterocycl Compd (N Y) 2019. [DOI: 10.1007/s10593-019-02557-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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22
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Sequencing [4 + 1]-Cycloaddition and Aza-Michael Addition Reactions: A Diastereoselective Cascade for the Rapid Access of Pyrido[2′,1′:2,3]/Thiazolo[2′,3′:2,3]imidazo[1,5-a]quinolone Scaffolds as Potential Antibacterial and Anticancer Motifs. J Org Chem 2019; 84:14476-14486. [DOI: 10.1021/acs.joc.9b01919] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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23
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Diversity-Oriented Synthesis of Imidazo-Dipyridines with Anticancer Activity via the Groebke–Blackburn–Bienaymé and TBAB-Mediated Cascade Reaction in One Pot. J Org Chem 2019; 84:12632-12638. [DOI: 10.1021/acs.joc.9b01385] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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24
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25
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Modern methods for the synthesis of δ-carbolines. Russ Chem Bull 2019. [DOI: 10.1007/s11172-019-2475-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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26
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Cooperation of Mn(III)/Brønsted Acid for the Synthesis of Quindoline Derivatives via Dehydroxylation/Azidation/Cyclization Cascade of Diaryl(1H-indol-2-yl)methanols with Trimethylsilyl Azide. Org Lett 2019; 21:2039-2042. [DOI: 10.1021/acs.orglett.9b00164] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Cu-Catalyzed Oxidative 3-Amination of Indoles via Formation of Indolyl(aryl)iodonium Imides Using o-Substituted (Diacetoxyiodo)arene as a High-Performance Hypervalent Iodine Compound. Molecules 2019; 24:molecules24061147. [PMID: 30909483 PMCID: PMC6471596 DOI: 10.3390/molecules24061147] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 03/14/2019] [Accepted: 03/21/2019] [Indexed: 11/20/2022] Open
Abstract
An oxidative 3-amination of indole derivatives using hypervalent iodine(III) and bissulfonimides, which proceeds via the formation of indolyl(aryl)iodonium imides, was developed. This reaction was followed by an indole-selective copper-catalyzed oxidative C–N coupling reaction to obtain 3-amino indole derivatives as single regioisomers. o-Alkoxy(diacetoxyiodo)arenes showed higher reactivity in the reaction than o-alkyl(diacetoxyiodo)arenes, efficiently promoting the formation of indolyl(aryl)iodonium imides in the first step.
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28
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Synthesis and Optical Properties of Alkaloid Quindoline, Its Structural Analogues and Substituted δ‐Carbolines. ChemistrySelect 2019. [DOI: 10.1002/slct.201803515] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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29
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Four-component, three-step cascade reaction: an effective synthesis of indazole-fused triazolo[5,1-c]quinoxalines. NEW J CHEM 2019. [DOI: 10.1039/c8nj06299d] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
An efficient four-component, three-step cascade synthesis of indazole-fused triazolo[5,1-c]quinoxalines has been described. Notable features of this protocol include simple starting materials, reduced synthetic steps, and good yields.
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Copper-Catalyzed Indole-Selective C-N Coupling Reaction of Indolyl(2-alkoxy-phenyl)iodonium Imides: Effect of Substituent on Iodoarene as Dummy Ligand. J Org Chem 2018; 83:14827-14833. [PMID: 30371085 DOI: 10.1021/acs.joc.8b02676] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
A monoalkoxy phenyl group as a dummy ligand on indolyl(aryl)iodonium imides, which is related to the N-I bonding hypervalent iodine(III) compound, for the copper-catalyzed indole-selective C-N coupling reaction was designed to provide 3-bissulfonimido-indole derivatives in high yields. In particular, the use of indolyl(2-butoxylphenyl)iodonium bissulfonimides indicated the high indole selectivity. Furthermore, this reaction was applied for the one-pot synthesis of 3-bissulfonimido-indole derivatives directly from indoles with bissulfonimides and (diacetoxyiodo)-2-butoxybenzene in the presence of Cu(MeCN)4BF4 catalyst.
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Transition-Metal-Free, Brønsted Acid-Mediated Cascade Sequence in the Reaction of Propargyl Alcohols with Sulfonamido-indoles/-indolines: Highly Substituted δ- and α-Carbolines. J Org Chem 2018; 83:15043-15056. [DOI: 10.1021/acs.joc.8b02293] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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32
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Orally Effective Aminoalkyl 10H-Indolo[3,2-b]quinoline-11-carboxamide Kills the Malaria Parasite by Inhibiting Host Hemoglobin Uptake. ChemMedChem 2018; 13:2581-2598. [PMID: 30358112 DOI: 10.1002/cmdc.201800579] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Revised: 10/10/2018] [Indexed: 12/26/2022]
Abstract
A series of indolo[3,2-b]quinoline-C11-carboxamides were synthesized by incorporation of aminoalkyl side chains into the core of indolo[3,2-b]quinoline-C11-carboxylic acid. Their in vitro antiplasmodial evaluation against Plasmodium falciparum led to the identification of a 2-(piperidin-1-yl)ethanamine-linked analogue {2-bromo-N-[2-(piperidin-1-yl)ethyl]-10H-indolo[3,2-b]quinoline-11-carboxamide (3 g)} (IC50 =1.3 μm) as the most promising compound exhibiting good selectivity indices against mammalian cell lines. The kill kinetics on erythrocytic-stage parasites revealed that 3 g caused complete killing of only the trophozoite-stage parasites. Mechanistic studies showed that 3 g targets the food vacuole of the parasite and inhibits hemoglobin uptake, β-hematin formation, and the basic endocytic processes of the parasite. Analogue 3 g was found to be orally bioavailable, and its curative antimalarial studies at 50 mg per kg p.o. against a Plasmodium berghei (ANKA)-infected mouse model revealed that mice treated with 3 g showed 27-35 % suppression of parasitemia with an increase in life span relative to untreated, control mice. Thus, the present work demonstrated a proof of concept for the oral efficacy of indolo[3,2-b]quinoline-C11-carboxamides.
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Metal-Free [2 + 2 + 2] Cycloaddition of Ynamide-Nitriles with Ynamides: A Highly Regio- and Chemoselective Synthesis of δ-Carboline Derivatives. J Org Chem 2018; 83:13308-13324. [PMID: 30353730 DOI: 10.1021/acs.joc.8b02112] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
A metal-free formal [2 + 2 + 2] cycloaddition of functionalized ynamide-nitriles with ynamides is disclosed which offers highly efficient access to polysubstituted δ-carboline derivatives under the mediation of TfOH. This strategy is highly regioselective and chemoselective and displays mild conditions, high yields, and efficiency (within 1 min) in addition to substrates scopes (56 examples).
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34
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Preparation of Pyrido[2,3-b
]indole Derivatives Using Silicates of Group 1 and 2 Metals. J Heterocycl Chem 2018. [DOI: 10.1002/jhet.3284] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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35
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A Ligand/Additive/Base-Free C(sp2
)-H Activation and Isocyanide Insertion in PEG-400: Synthesis of Indolizine/Imidazoline-Fused Heterocycles. ChemistrySelect 2018. [DOI: 10.1002/slct.201800397] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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36
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Indium-Catalyzed Annulation of o-Acylanilines with Alkoxyheteroarenes: Synthesis of Heteroaryl[b]quinolines and Subsequent Transformation to Cryptolepine Derivatives. Molecules 2018; 23:molecules23040838. [PMID: 29621195 PMCID: PMC6017974 DOI: 10.3390/molecules23040838] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 03/25/2018] [Accepted: 03/31/2018] [Indexed: 12/30/2022] Open
Abstract
We disclose herein the first synthetic method that is capable of offering heteroaryl[b]quinolines (HA[b]Qs) with structural diversity, which include tricyclic and tetracyclic structures with (benzo)thienyl, (benzo)furanyl, and indolyl rings. The target HA[b]Q is addressed by the annulation of o-acylanilines and MeO–heteroarenes with the aid of an indium Lewis acid that effectively works to make two different types of the N–C and C–C bonds in one batch. A series of indolo[3,2-b]quinolines prepared here can be subsequently transformed to structurally unprecedented cryptolepine derivatives. Mechanistic studies showed that the N–C bond formation is followed by the C–C bond formation. The indium-catalyzed annulation reaction thus starts with the nucleophilic attack of the NH2 group of o-acylanilines to the MeO-connected carbon atom of the heteroaryl ring in an SNAr fashion, and thereby the N–C bond is formed. The resulting intermediate then cyclizes to make the C–C bond through the nucleophilic attack of the heteroaryl-ring-based carbon atom to the carbonyl carbon atom, providing the HA[b]Q after aromatizing dehydration.
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37
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Convenient synthesis of 10 H -indolo[3,2- b ]quinolines and 6 H -indolo[2,3- b ]quinolines by sequential chemoselective Suzuki reaction followed by double C-N coupling. Tetrahedron 2018. [DOI: 10.1016/j.tet.2018.01.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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38
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Copper-Catalyzed Tandem Imine Formation, Sonogashira Coupling and Intramolecular Hydroamination: A Facile Synthesis of 3-Aryl-γ−carbolines. ChemistrySelect 2017. [DOI: 10.1002/slct.201702025] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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39
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Direct and Selective 3-Amidation of Indoles Using Electrophilic N-[(Benzenesulfonyl)oxy]amides. Org Lett 2017; 19:1314-1317. [PMID: 28281340 DOI: 10.1021/acs.orglett.7b00358] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Selective C-H amidation of 1H-indoles at the C3 position is reported as a direct entry to biologically important 3-aminoindoles. This transformation is achieved using novel N-[(benzenesulfonyl)oxy]amides as electrophilic nitrogen agents in the presence of ZnCl2. Interestingly, analogous reactions in the absence of ZnCl2 resulted in the formation of indole aminal products.
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40
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Regioselective switching approach for the synthesis of α and δ carboline derivatives. Chem Commun (Camb) 2017; 53:1676-1679. [DOI: 10.1039/c6cc09468f] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
A metal-free protocol for accessing both α and δ-carboline derivatives, starting from a common indolylchalcone oxime ester precursor is reported.
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41
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Abstract
Fluorescence is a remarkable property of many natural products in addition to their medicinal and biological value. Herein, we provide a review of these peculiar secondary metabolites to stimulate prospecting of them as original fluorescent tracers, endowed with unique photophysical properties and with applications in most fields of biology.
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42
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Rhodium-CatalyzedN-tert-Butoxycarbonyl (Boc) Amination by Directed CH Bond Activation. Adv Synth Catal 2016. [DOI: 10.1002/adsc.201600410] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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43
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Rhodium(III)-Catalyzed Cascade Cyclization/Electrophilic Amidation for the Synthesis of 3-Amidoindoles and 3-Amidofurans. Org Lett 2016; 18:2058-61. [DOI: 10.1021/acs.orglett.6b00689] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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44
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Sulfonamide and Tertiary Amine as Nucleophiles in Pd(II)-Catalyzed Diamination of Alkynes: Synthesis of Tetracyclic Indolobenzothiazine S,S-Dioxides. Org Lett 2015; 17:5256-9. [DOI: 10.1021/acs.orglett.5b02621] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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45
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Small molecule PZL318: forming fluorescent nanoparticles capable of tracing their interactions with cancer cells and activated platelets, slowing tumor growth and inhibiting thrombosis. Int J Nanomedicine 2015; 10:5273-92. [PMID: 26345234 PMCID: PMC4554418 DOI: 10.2147/ijn.s88052] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Low selectivity of chemotherapy correlates with poor outcomes of cancer patients. To improve this issue, a novel agent, N-(1-[3-methoxycarbonyl-4-hydroxyphenyl]-β-carboline-3-carbonyl)-Trp-Lys-OBzl (PZL318), was reported here. The transmission electron microscopy, scanning electron microscopy, and atomic force microscopy images demonstrated that PZL318 can form nanoparticles. Fluorescent and confocal images visualized that PZL318 formed fluorescent nanoparticles capable of targeting cancer cells and tracing their interactions with cancer cells. In vitro, 40 μM of PZL318 inhibited the proliferation of tumorigenic cells, but not nontumorigenic cells. In vivo, 10 nmol/kg of PZL318 slowed the tumor growth of S180 mice and alleviated the thrombosis of ferric chloride-treated ICR mice, while 100 μmol/kg of PZL318 did not injure healthy mice and they exhibited no liver toxicity. By analyzing Fourier transform–mass spectrometry and rotating-frame Overhauser spectroscopy (ROESY) two-dimensional nuclear magnetic resonance spectra, the chemical mechanism of PZL318-forming trimers and nanoparticles was explored. By using mesoscale simulation, a nanoparticle of 3.01 nm in diameter was predicted containing 13 trimers. Scavenging free radicals, downregulating sP-selectin expression and intercalating toward DNA were correlated with the antitumor mechanism of PZL318.
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Combined isocyanide-based multi-component Ullmann-type reaction: an efficient access to novel nitrogen-containing pentacyclic compounds. Mol Divers 2015; 19:797-805. [DOI: 10.1007/s11030-015-9622-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Accepted: 07/19/2015] [Indexed: 12/29/2022]
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47
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Synthesis of Naphtho[1',2':4,5]imidazo[1,2-a]pyridines and Imidazo[5,1,2-cd]indolizines Through Pd-Catalyzed Cycloaromatization of 2-Phenylimidazo[1,2-a]pyridines with Alkynes. J Org Chem 2015; 80:7508-18. [PMID: 26168267 DOI: 10.1021/acs.joc.5b01092] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In this paper, palladium-catalyzed oxidative cycloaromatization of 2-phenylimidazo[1,2-a]pyridine (PIP) with internal alkyne is studied. From this reaction, two classes of fused N-heterocycle, naphtho[1',2':4,5]imidazo[1,2-a]pyridine (NIP) and imidazo[5,1,2-cd]indolizine (IID), were formed through dehydrogenative coupling featured with cleavage of the C-H bonds located on different moiety of the PIP substrates. Moreover, when 5-methyl-2-phenylimidazo [1,2-a]pyridine or 2-mesitylimidazo[1,2-a]pyridine was used, either NIP or IID could be obtained as an exclusive product with good efficiency. Intriguingly, Pd(II) showed different action mode in promoting this reaction compared with Rh(III) and led to the formation of NIP with reversed regio-selectivity for the reaction of asymmetrical alkyne.
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48
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Palladium-catalyzed regioselective aerobic oxidative cyclization via C–H activation in chloroquine analogues: synthesis and cytotoxic study. MONATSHEFTE FUR CHEMIE 2015. [DOI: 10.1007/s00706-015-1474-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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49
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Efficient synthesis of α- and δ-carbolines by sequential Pd-catalyzed site-selective C–C and twofold C–N coupling reactions. Org Biomol Chem 2015; 13:1375-86. [DOI: 10.1039/c4ob02226b] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Two concise and efficient approaches were developed for the synthesis of α- and δ-carboline derivatives.
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50
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Copper(II) catalyzed expeditious synthesis of furoquinoxalines through a one-pot three-component coupling strategy. Org Lett 2014; 16:4528-31. [PMID: 25115644 DOI: 10.1021/ol502072k] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Microwave assisted one-pot transformation has been developed for the synthesis of biologically significant polysubstituted furoquinoxalines in good to excellent yields through a copper(II) catalyzed three-component coupling of o-phenylenediamine, ethylglyoxalate, and terminal alkyne, known as A(3)-coupling, followed by 5-endo-dig cyclization.
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