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Singh S, Dhanawat M, Gupta S, Kumar D, Kakkar S, Nair A, Verma I, Sharma P. Naturally Inspired Pyrimidines Analogues for Alzheimer's Disease. Curr Neuropharmacol 2021; 19:136-151. [PMID: 33176653 PMCID: PMC8033975 DOI: 10.2174/1570159x18666201111110136] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 10/28/2020] [Accepted: 11/06/2020] [Indexed: 01/17/2023] Open
Abstract
Alzheimer's disease (AD) is a multifarious and developing neurodegenerative disorder. The treatment of AD is still a challenge and availability of drug therapy on the basis of symptoms is not up to the mark. In the context of existence, which is getting worse for the human brain, it is necessary to take care of all critical measures. The disease is caused due to multidirectional pathology of the body, which demands the multi-target-directed ligand (MTDL) approach. This gives hope for new drugs for AD, summarized here in with the pyrimidine based natural product inspired molecule as a lead. The review is sufficient in providing a list of chemical ingredients of the plant to cure AD and screen them against various potential targets of AD. The synthesis of a highly functionalized scaffold in one step in a single pot without isolating the intermediate is a challenging task. In few examples, we have highlighted the importance of this kind of reaction, generally known as multi-component reaction. Multi-component is a widely accepted technique by the drug discovery people due to its high atom economy. It reduces multi-step process to a one-step process, therefore the compounds library can be made in minimum time and cost. This review has highlighted the importance of multicomponent reactions by giving the example of active scaffolds of pyrimidine/fused pyrimidines. This would bring importance to the fast as well as smart synthesis of bio-relevant molecules.
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Affiliation(s)
- Shivani Singh
- Department of Pharmaceutical Sciences, Somany College of Pharmacy, Rewari, Haryana, India
- Department of Pharmaceutical Sciences, Maharishi Dayanand University, Rohtak, Haryana, India
| | - Meenakshi Dhanawat
- Department of Pharmaceutical Sciences, M. M. College of Pharmacy, M. M. (Deemed to be University), Mullana, (Ambala), Haryana, India
| | - Sumeet Gupta
- Department of Pharmaceutical Sciences, M. M. College of Pharmacy, M. M. (Deemed to be University), Mullana, (Ambala), Haryana, India
| | - Deepak Kumar
- Department of Pharmaceutical Sciences, Indra Gandhi University, Mirpur, Rewari Haryana, India
| | - Saloni Kakkar
- Department of Pharmaceutical Sciences, Maharishi Dayanand University, Rohtak, Haryana, India
| | - Anroop Nair
- Department of Pharmaceutical Sciences, College of Clinical Pharmacy, King Faisal University, Al-Ahsa 31982, Saudi Arabia
| | - Inderjeet Verma
- Department of Pharmaceutical Sciences, M. M. College of Pharmacy, M. M. (Deemed to be University), Mullana, (Ambala), Haryana, India
| | - Prerna Sharma
- Department of Pharmaceutical Sciences, M. M. College of Pharmacy, M. M. (Deemed to be University), Mullana, (Ambala), Haryana, India
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Sobenina LN, Sagitova EF, Markova MV, Ushakov IA, Ivanov AV, Trofimov BA. Acylethynylpyrroles as a platform for the one-pot access to 2-(pyrrol-2-yl)-3-acylpyridines via the dihydrogenative annelation with propargylamine. Tetrahedron Lett 2018. [DOI: 10.1016/j.tetlet.2018.09.066] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Burrell RC, Turley WA, Bonacorsi SJ. Synthesis of stable isotope-labeled epothilone D using a degradation-reconstruction approach. J Labelled Comp Radiopharm 2015; 58:361-9. [PMID: 26158758 DOI: 10.1002/jlcr.3312] [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: 03/27/2015] [Revised: 05/22/2015] [Accepted: 06/05/2015] [Indexed: 11/11/2022]
Abstract
The stabilization of microtubules using epothilones represents a novel mechanism of action to treat Alzheimer's disease. Epothilone D is one such microtubule-stabilizing drug that has been investigated by Bristol-Myers Squibb. An important step in the development process was the synthesis of a stable isotope-labeled analog for use in bioanalytical assays to accurately quantify the concentration of the drug in biological samples. A novel synthetic route to stable isotope-labeled epothilone D is described. The synthetic route was based on a strategy to degrade epothilone B and then use that key intermediate to reconstruct stable isotope-labeled epothilone D. Epothilone B was treated with potassium osmate and sodium periodate. The thiazole moiety in epothilone B was efficiently cleaved to give (1S,3S,7S,10R,11S,12S,16R)-3-acetyl-7,11-dihydroxy-8,8,10,12,16-pentamethyl-4,17-dioxabicyclo[14.1.0]heptadecane-5,9-dione. The epoxide in the macrocyclic ring of that intermediate was cleanly removed by treatment with tungsten hexachloride and n-butyllithium to give the corresponding olefin (4S,7R,8S,9S,16S,Z)-16-acetyl-4,8-dihydroxy-5,5,7,9,13-pentamethyloxacyclohexadec-13-ene-2,6-dione. Bis(triethylsilyl) protection produced (4S,7R,8S,9S,16S,Z)-16-acetyl-5,5,7,9,13-pentamethyl-4,8-bis(triethylsilyloxy)-oxacyclohexadec-13-ene-2,6-dione. This intermediate was coupled to a stable isotope-labeled thiazole using a Wittig reaction as the key step to provide (13)C5, (15)N-labeled epothilone D. In summary, the synthesis was completed in nine total steps, only six of which involved isotopically labeled reagents. A total of 168 mg of (13)C5, (15)N-labeled epothilone D was prepared in an 8% overall yield from (13)C2, (15)N-labeled thioacetamide and (13)C3-labeled ethyl bromopyruvate.
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Affiliation(s)
- Richard C Burrell
- Bristol-Myers Squibb Research and Development, Discovery Chemistry Platforms, 5 Research Parkway, Wallingford, CT, 06492, USA
| | - Wesley A Turley
- Bristol-Myers Squibb Research and Development, Discovery Chemistry Platforms, 5 Research Parkway, Wallingford, CT, 06492, USA
| | - Samuel J Bonacorsi
- Bristol-Myers Squibb Research and Development, Discovery Chemistry Platforms, Route 206 and Province Line Road, Princeton, NJ, 08540, USA
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Flores JA, Pal K, Carroll ME, Pink M, Karty JA, Mindiola DJ, Caulton KG. Mechanistic Understanding of a Silver Pyridylpyrrolide as a Catalyst for 3 + 2 Cyclization of a Nitrile with Diazo Ester. Organometallics 2014. [DOI: 10.1021/om400756t] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Jaime A. Flores
- Department of Chemistry and Molecular Structure
Center, Indiana University, Bloomington, Indiana 47405, United States
| | - Kuntal Pal
- Department of Chemistry and Molecular Structure
Center, Indiana University, Bloomington, Indiana 47405, United States
| | - Maria E. Carroll
- Department of Chemistry and Molecular Structure
Center, Indiana University, Bloomington, Indiana 47405, United States
| | - Maren Pink
- Department of Chemistry and Molecular Structure
Center, Indiana University, Bloomington, Indiana 47405, United States
| | - Jonathan A. Karty
- Department of Chemistry and Molecular Structure
Center, Indiana University, Bloomington, Indiana 47405, United States
| | - Daniel J. Mindiola
- Department of Chemistry and Molecular Structure
Center, Indiana University, Bloomington, Indiana 47405, United States
| | - Kenneth G. Caulton
- Department of Chemistry and Molecular Structure
Center, Indiana University, Bloomington, Indiana 47405, United States
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Thiopeptide antibiotics: retrospective and recent advances. Mar Drugs 2014; 12:317-51. [PMID: 24445304 PMCID: PMC3917276 DOI: 10.3390/md12010317] [Citation(s) in RCA: 129] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Revised: 12/13/2013] [Accepted: 12/16/2013] [Indexed: 02/06/2023] Open
Abstract
Thiopeptides, or thiazolyl peptides, are a relatively new family of antibiotics that already counts with more than one hundred different entities. Although they are mainly isolated from soil bacteria, during the last decade, new members have been isolated from marine samples. Far from being limited to their innate antibacterial activity, thiopeptides have been found to possess a wide range of biological properties, including anticancer, antiplasmodial, immunosuppressive, etc. In spite of their ribosomal origin, these highly posttranslationally processed peptides have posed a fascinating synthetic challenge, prompting the development of various methodologies and strategies. Regardless of their limited solubility, intensive investigations are bringing thiopeptide derivatives closer to the clinic, where they are likely to show their veritable therapeutic potential.
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Gers CF, Nordmann J, Kumru C, Frank W, Müller TJJ. Solvatochromic Fluorescent 2-Substituted 3-Ethynyl Quinoxalines: Four-Component Synthesis, Photophysical Properties, and Electronic Structure. J Org Chem 2014; 79:3296-310. [DOI: 10.1021/jo4025978] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- Charlotte F. Gers
- Institut für Organische Chemie und Makromolekulare Chemie and ‡Institut für
Anorganische Chemie und Strukturchemie, Heinrich-Heine Universität Düsseldorf, Universitätstrasse 1, D-40225 Düsseldorf, Germany
| | - Jan Nordmann
- Institut für Organische Chemie und Makromolekulare Chemie and ‡Institut für
Anorganische Chemie und Strukturchemie, Heinrich-Heine Universität Düsseldorf, Universitätstrasse 1, D-40225 Düsseldorf, Germany
| | - Ceyda Kumru
- Institut für Organische Chemie und Makromolekulare Chemie and ‡Institut für
Anorganische Chemie und Strukturchemie, Heinrich-Heine Universität Düsseldorf, Universitätstrasse 1, D-40225 Düsseldorf, Germany
| | - Walter Frank
- Institut für Organische Chemie und Makromolekulare Chemie and ‡Institut für
Anorganische Chemie und Strukturchemie, Heinrich-Heine Universität Düsseldorf, Universitätstrasse 1, D-40225 Düsseldorf, Germany
| | - Thomas J. J. Müller
- Institut für Organische Chemie und Makromolekulare Chemie and ‡Institut für
Anorganische Chemie und Strukturchemie, Heinrich-Heine Universität Düsseldorf, Universitätstrasse 1, D-40225 Düsseldorf, Germany
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Dawsey AC, Li V, Hamilton KC, Wang J, Williams TJ. Copper-catalyzed oxidation of azolines to azoles. Dalton Trans 2012; 41:7994-8002. [PMID: 22460353 DOI: 10.1039/c2dt00025c] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report herein convenient, aerobic conditions for the oxidation of thiazolines to thiazoles and data regarding the oxidation mechanism. These reactions feature operationally simple and environmentally benign conditions and proceed in good yield to afford the corresponding azoles, thus enabling the inexpensive preparation of valuable molecular building blocks. Incorporation of a novel diimine-ligated copper catalyst, [((Mes)DAB(Me))Cu(II)(OH(2))(3)](2+) [(-)OTf](2), provides increased reaction efficiency in many cases. In other cases copper-free conditions involving a stoichiometric quantity of base affords superior results.
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Affiliation(s)
- Anna C Dawsey
- University of Southern California, 837 Bloom Walk, Los Angeles, California 90089-1661, USA
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Kantevari S, Patpi SR, Addla D, Putapatri SR, Sridhar B, Yogeeswari P, Sriram D. Facile diversity-oriented synthesis and antitubercular evaluation of novel aryl and heteroaryl tethered pyridines and dihydro-6H-quinolin-5-ones derived via variants of the Bohlmann-Rahtz Reaction. ACS COMBINATORIAL SCIENCE 2011; 13:427-35. [PMID: 21699150 DOI: 10.1021/co2000604] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The diversity oriented synthesis of substituted pyridines and dihydro-6H-quinolin-5-ones tethered with aryls and heteroaryls was achieved in very good yields through CeCl(3)·7H(2)O-NaI catalyst via variants of the Bohlmann-Rahtz reaction. β-Enaminones derived from various aryl and heteroaryl methyl ketones were regioselectively reacted with ethyl acetoacetate or 5,5-dimethylcyclohexane-1,3-dione or 4,4-dimethylcyclohexane-1,3-dione and ammonium acetate refluxing in 2-propanol. Applicability of nontoxic cerium catalyst, high reactivity with wide range of aryl and heteroaryl β-enaminones leading to diverse analogues, operational simplicity, and shorter reaction time at comparatively low temperatures are prominent features of the developed protocol. These synthesized substituted pyridines and dihydro-6H-quinolin-5-one analogues have been evaluated for their in vitro antimycobacterial activity against Mycobacterium tuberculosis H37Rv (MTB) by agar dilution method. Among the 48 compounds screened, six compounds 2-(5-chlorothiophen-2-yl)-7,7-dimethyl-7,8-dihydro-6H-quinolin-5-one 4{13,2}, 2-(5-bromothiophen-2-yl)-7,7-dimethyl-7,8-dihydro-6H-quinolin-5-one 4{14,2}, 2-(5-chloro thiophen-2-yl)-6,6-dimethyl-7,8-dihydroquinolin-5(6H)-one 4{13,3}, and 2-(5-bromothiophen-2-yl)-6,6-dimethyl-7,8-dihydroquinolin-5(6H)-one 4{14,3}, 7,7-dimethyl-2-(naphthalen-2-yl)-7,8-dihydroquinoline-5(6H)-one 4{6,2}, 6,6-dimethyl-2-(naphthalen-2-yl)-7,8-di hydroquinolin-5(6H)-one 4{6,3} resulted as the most promising antitubercular agents.
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Affiliation(s)
| | | | | | | | | | - Perumal Yogeeswari
- Medicinal Chemistry and Antimycobacterial Research Laboratory, Pharmacy Group, Birla Institute of Technology & Science-Pilani, Hyderabad Campus, Jawahar Nagar, Hyderabad-500078, India
| | - Dharmarajan Sriram
- Medicinal Chemistry and Antimycobacterial Research Laboratory, Pharmacy Group, Birla Institute of Technology & Science-Pilani, Hyderabad Campus, Jawahar Nagar, Hyderabad-500078, India
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10
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Salaheldin AM, Al-Sheikh MA. Beta-enamino esters in heterocyclic synthesis: synthesis of pyrazolone and pyridinone derivatives. Molecules 2010; 15:4359-68. [PMID: 20657446 PMCID: PMC6264444 DOI: 10.3390/molecules15064359] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2010] [Revised: 05/22/2010] [Accepted: 05/26/2010] [Indexed: 11/30/2022] Open
Abstract
An efficient and convenient synthesis of pyrrolidinones and pyridinones utilizing enamino esters as starting material has been described. The structures of the compounds obtained were confirmed by spectral and elemental analyses.
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Affiliation(s)
| | - Mariam Abdullah Al-Sheikh
- Department of Chemistry, Girls College of Education, Jeddah, P. O. Box 138016, Jeddah 21323, Saudi Arabia
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: + 966 0505694706
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11
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Bohlmann-Rahtz cyclodehydration of aminodienones to pyridines using N-iodosuccinimide. Molecules 2010; 15:3211-27. [PMID: 20657473 PMCID: PMC6263277 DOI: 10.3390/molecules15053211] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2010] [Accepted: 04/20/2010] [Indexed: 11/17/2022] Open
Abstract
Cyclodehydration of Bohlmann-Rahtz aminodienone intermediates using N-iodosuccinimide as a Lewis acid proceeds at low temperature under very mild conditions to give the corresponding 2,3,6-trisubstituted pyridines in high yield and with total regiocontrol.
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12
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Ciufolini MA, Lefranc D. Micrococcin P1: Structure, biology and synthesis. Nat Prod Rep 2010; 27:330-42. [DOI: 10.1039/b919071f] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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13
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Jagadhani SG, Shelke SN, Karale BK. Synthesis and antimicrobial screening of some chromones and thiazepines by conventional and microwave irradiation. HETEROCYCL COMMUN 2009. [DOI: 10.1515/hc.2009.15.3.159] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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14
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Martin T, Verrier C, Hoarau C, Marsais F. Direct C-2 Arylation of Alkyl 4-Thiazolecarboxylates: New Insights in Synthesis of Heterocyclic Core of Thiopeptide Antibiotics. Org Lett 2008; 10:2909-12. [DOI: 10.1021/ol801035c] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Thibaut Martin
- Institut de Chimie Organique Fine (IRCOF) associé au CNRS (UMR 6014), INSA et Université de Rouen, BP08 76131 Mont Saint Aignan, France
| | - Cécile Verrier
- Institut de Chimie Organique Fine (IRCOF) associé au CNRS (UMR 6014), INSA et Université de Rouen, BP08 76131 Mont Saint Aignan, France
| | - Christophe Hoarau
- Institut de Chimie Organique Fine (IRCOF) associé au CNRS (UMR 6014), INSA et Université de Rouen, BP08 76131 Mont Saint Aignan, France
| | - Francis Marsais
- Institut de Chimie Organique Fine (IRCOF) associé au CNRS (UMR 6014), INSA et Université de Rouen, BP08 76131 Mont Saint Aignan, France
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Hughes RA, Moody CJ. From Amino Acids to Heteroaromatics—Thiopeptide Antibiotics, Nature's Heterocyclic Peptides. Angew Chem Int Ed Engl 2007; 46:7930-54. [PMID: 17854013 DOI: 10.1002/anie.200700728] [Citation(s) in RCA: 231] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Amino acids, the building blocks of proteins, also serve as precursors to a wide range of other naturally occurring substances including alkaloids, antibiotics, and, the subject of this Review, heterocyclic peptides. Simple alpha-amino acids are converted into complex arrays of heteroaromatic rings that display interesting and potent biological activity. The thiopeptide antibiotics, with their complex molecular architectures, are wonderful examples. In this Review we show how organic chemists have developed innovative methods for the synthesis of the heterocyclic ring systems, including routes inspired by the likely biosynthetic processes, and successfully assembled such building blocks into the final target molecule by application of orthogonal protecting groups and coupling methodologies.
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Affiliation(s)
- Rachael A Hughes
- Department of Chemistry, University of Oslo, P.O. Box 1033, Blindern, 0315-Oslo, Norway
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Hughes R, Moody C. Von Aminosäuren zu Heteroarenen – Thiopeptid-Antibiotika als heterocyclische Peptide aus der Natur. Angew Chem Int Ed Engl 2007. [DOI: 10.1002/ange.200700728] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Hughes RA, Thompson SP, Alcaraz L, Moody CJ. Total synthesis of the thiopeptide antibiotic amythiamicin D. J Am Chem Soc 2006; 127:15644-51. [PMID: 16262432 DOI: 10.1021/ja0547937] [Citation(s) in RCA: 132] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The thiopeptide (or thiostrepton) antibiotics are a class of sulfur containing highly modified cyclic peptides with interesting biological properties, including reported activity against MRSA and malaria. Described herein is the total synthesis of the thiopeptide natural product amythiamicin D, which utilizes a biosynthesis-inspired hetero-Diels-Alder route to the pyridine core of the antibiotic as a key step. Preliminary studies using a range of serine-derived 1-ethoxy-2-azadienes established that hetero-Diels-Alder reaction with N-acetylenamines proceeded efficiently under microwave irradiation to give 2,3,6-trisubstituted pyridines. The thiazole building blocks of the antibiotic were obtained by either classical Hantzsch reactions or by dirhodium(II)-catalyzed chemoselective carbene N-H insertion followed by thionation, and were combined to give the bis-thiazole that forms the left-hand fragment of the antibiotic. The key Diels-Alder reaction of a tris-thiazolyl azadiene with benzyl 2-(1-acetylaminoethenyl)thiazole-4-carboxylate gave the core tetrathiazolyl pyridine, which was elaborated into the natural product by successive incorporation of glycine and bis-thiazole fragments followed by macrocyclization.
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Affiliation(s)
- Rachael A Hughes
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
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Bagley MC, Glover C. Synthesis of methyl sulfomycinate, sulfomycinic amide and sulfomycinine, degradation products of the sulfomycin thiopeptide antibiotics. Tetrahedron 2006. [DOI: 10.1016/j.tet.2005.09.134] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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SYNTHESIS OF 6-(6'-ARYLPYRIDIN-2'-YL) AND 6-(4',6'-DIARYLPYRIDIN-2'-YL)-3(4H)-OXO-1,4-BENZOTHIAZINES UNDER MICROWAVE IRRADIATION CONDITIONS. HETEROCYCL COMMUN 2006. [DOI: 10.1515/hc.2006.12.3-4.197] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Bagley MC, Jenkins RL, Lubinu MC, Mason C, Wood R. A Simple Continuous Flow Microwave Reactor. J Org Chem 2005; 70:7003-6. [PMID: 16095337 DOI: 10.1021/jo0510235] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A new simple procedure for microwave-assisted organic synthesis under continuous flow processing has been developed for use in a monomodal microwave synthesizer with direct temperature control using the instrument's in-built IR sensor. This design makes optimum use of the standing wave cavity to improve the energy efficiency of microwave-assisted flow reactions.
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Affiliation(s)
- Mark C Bagley
- School of Chemistry, Main Building, Cardiff University, Park Place, Cardiff CF10 3AT, Wales, United Kingdom.
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Affiliation(s)
- Mark C Bagley
- School of Chemistry, Main Building, Cardiff University, Park Place, Cardiff, CF10 3AT, Wales, United Kingdom.
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Bagley MC, Chapaneri K, Dale JW, Xiong X, Bower J. One-Pot Multistep Bohlmann−Rahtz Heteroannulation Reactions: Synthesis of Dimethyl Sulfomycinamate. J Org Chem 2005; 70:1389-99. [PMID: 15704975 DOI: 10.1021/jo048106q] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
[reaction: see text] The synthesis of dimethyl sulfomycinamate, the acidic methanolysis product of the sulfomycin family of thiopeptide antibiotics, from methyl 2-oxo-4-(trimethylsilyl)but-3-ynoate is achieved in a 2,3,6-trisubstituted pyridine synthesis that proceeds with total regiocontrol in 13 steps by the Bohlmann-Rahtz heteroannulation of a 1-(oxazol-4-yl)enamine or in 12 steps and 9% yield by three-component cyclocondensation with N-[3-oxo-3-(oxazol-4-yl)propanoyl]serine and ammonia in ethanol.
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Affiliation(s)
- Mark C Bagley
- School of Chemistry, Main Building, Cardiff University, Park Place, Cardiff, CF10 3AT, United Kingdom.
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Zhao Y, Zhao J, Zhou Y, Lei Z, Li L, Zhang H. Efficient synthesis of β-amino-α,β-unsaturated carbonyl compounds. NEW J CHEM 2005. [DOI: 10.1039/b419254k] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Chapter 5.5 Five-membered ring systems: With N and S (Se) atoms. ACTA ACUST UNITED AC 2005. [DOI: 10.1016/s0959-6380(05)80051-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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Abstract
Although fire is now rarely used in synthetic chemistry, it was not until Robert Bunsen invented the burner in 1855 that the energy from this heat source could be applied to a reaction vessel in a focused manner. The Bunsen burner was later superseded by the isomantle, oil bath, or hot plate as a source for applying heat to a chemical reaction. In the past few years, heating and driving chemical reactions by microwave energy has been an increasingly popular theme in the scientific community. This nonclassical heating technique is slowly moving from a laboratory curiosity to an established technique that is heavily used in both academia and industry. The efficiency of "microwave flash heating" in dramatically reducing reaction times (from days and hours to minutes and seconds) is just one of the many advantages. This Review highlights recent applications of controlled microwave heating in modern organic synthesis, and discusses some of the underlying phenomena and issues involved.
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Affiliation(s)
- C Oliver Kappe
- Institute of Chemistry, Organic and Bioorganic Chemistry, Karl-Franzens University Graz, Heinrichstrasse 28, A-8010 Graz, Austria.
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Kappe CO. Kontrolliertes Erhitzen mit Mikrowellen in der modernen organischen Synthese. Angew Chem Int Ed Engl 2004. [DOI: 10.1002/ange.200400655] [Citation(s) in RCA: 241] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Bagley MC, Xiong X. Stereoselective Synthesis of the γ-Lactam Hydrolysate of the Thiopeptide Cyclothiazomycin. Org Lett 2004; 6:3401-4. [PMID: 15355062 DOI: 10.1021/ol0485870] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
[reaction: see text] Bohlmann-Rahtz pyridine synthesis of a chiral nonracemic enamine and thiazolylpropynone gives a terminal-protected pyridine-containing gamma-amino acid in high optical purity in a sequential one-pot multicomponent reaction that proceeds with total control of regiochemistry and with minimal racemization. Further elaboration has established the synthesis of the gamma-lactam acidic hydrolysate of the macrocyclic thiopeptide antibiotic cyclothiazomycin, a selective renin inhibitor, in only four steps and 30% overall yield and has confirmed its structure.
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Affiliation(s)
- Mark C Bagley
- School of Chemistry, Cardiff University, P.O. Box 912, Cardiff, CF10 3TB, UK.
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