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Telmesani R, Park SH, Lynch-Colameta T, Beeler AB. [2+2] Photocycloaddition of Cinnamates in Flow and Development of a Thiourea Catalyst. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201504454] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Telmesani R, Park SH, Lynch-Colameta T, Beeler AB. [2+2] Photocycloaddition of Cinnamates in Flow and Development of a Thiourea Catalyst. Angew Chem Int Ed Engl 2015; 54:11521-5. [PMID: 26136253 DOI: 10.1002/anie.201504454] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Indexed: 11/08/2022]
Abstract
Cyclobutanes derived from the dimerization of cinnamic acids are the core scaffolds of many molecules with potentially interesting biological activities. By utilizing a powerful flow photochemistry platform developed in our laboratory, we have evaluated the effects of flow on the dimerization of a range of cinnamate substrates. During the course of the study we also identified a bis(thiourea) catalyst that facilitates better reactivity and moderate diastereoselectivity in the reaction. Overall, we show that carrying out the reaction in flow in the presence of the catalyst affords consistent formation of predictable cyclobutane diastereomers.
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Martin V, Goodell JR, Ingham OJ, Porco JA, Beeler AB. Multidimensional reaction screening for photochemical transformations as a tool for discovering new chemotypes. J Org Chem 2014; 79:3838-46. [PMID: 24697145 PMCID: PMC4017617 DOI: 10.1021/jo500190b] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2014] [Indexed: 01/11/2023]
Abstract
We have developed an automated photochemical microfluidics platform that integrates a 1 kW high-pressure Hg vapor lamp and allows for analytical pulse flow or preparative continuous flow reactions. Herein, we will discuss the use of this platform toward the discovery of new chemotypes through multidimensional reaction screening. We will highlight the ability to discretely control wavelengths with optical filters, allowing for control of reaction outcomes.
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Leng B, Chichetti S, Su S, Beeler AB, Porco JA. Synthesis of a novel chemotype via sequential metal-catalyzed cycloisomerizations. Beilstein J Org Chem 2012; 8:1338-43. [PMID: 23019468 PMCID: PMC3458758 DOI: 10.3762/bjoc.8.153] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2012] [Accepted: 07/13/2012] [Indexed: 11/23/2022] Open
Abstract
Sequential cycloisomerizations of diynyl o-benzaldehyde substrates to access novel polycyclic cyclopropanes are reported. The reaction sequence involves initial Cu(I)-mediated cycloisomerization/nucleophilic addition to an isochromene followed by diastereoselective Pt(II)-catalyzed enyne cycloisomerization.
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Achard M, Beeler AB, Porco JA. Synthesis of azaphilone-based chemical libraries. ACS COMBINATORIAL SCIENCE 2012; 14:236-44. [PMID: 22330196 DOI: 10.1021/co300002x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The synthesis of azaphilone scaffolds that have been further diversified by cross coupling acylation and amine addition is reported. Methodology development also led to novel modifications including C5 acetoxylation and condensations producing isoquinolin-6(7H) structures. Overall, the library synthesis afforded three azaphilone sublibraries, including vinylogous pyridones which project diversity elements in four sectors of the azaphilone core.
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Balthaser BR, Maloney MC, Beeler AB, Porco JA, Snyder JK. Remodelling of the natural product fumagillol employing a reaction discovery approach. Nat Chem 2012; 3:969-73. [PMID: 22213919 PMCID: PMC3254213 DOI: 10.1038/nchem.1178] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
In the search for new biologically active molecules, diversity-oriented synthetic strategies break through the limitation of traditional library synthesis by sampling new chemical space. Many natural products can be regarded as intriguing starting points for diversity-oriented synthesis, wherein stereochemically rich core structures may be reorganized into chemotypes that are distinctly different from the parent structure. Ideally, to be suited to library applications, such transformations should be general and involve few steps. With this objective in mind, the highly oxygenated natural product fumagillol has been successfully remodelled in several ways using a reaction-discovery-based approach. In reactions with amines, excellent regiocontrol in a bis-epoxide opening/cyclization sequence can be obtained by size-dependent interaction of an appropriate catalyst with the parent molecule, forming either perhydroisoindole or perhydroisoquinoline products. Perhydroisoindoles can be further remodelled by cascade processes to afford either morpholinone or bridged 4,1-benzoxazepine-containing structures.
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K. Snyder J, C. Benson S, Lee L, Wei W, Ni F, David Janna Olmos J, R. Strom K, B. Beeler A, Chih-Chien Cheng K, Inglese J, Kota S, Takahashi V, Donny Strosberg A, H. Connor J, Guy Bushkin G. Truncated Aspidosperma Alkaloid-Like Scaffolds: Unique Structures for the Discovery of New, Bioactive Compounds. HETEROCYCLES 2012. [DOI: 10.3987/rev-11-sr(p)4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Pimparkar K, Yen B, Goodell JR, Martin VI, Lee WH, Porco JA, Beeler AB, Jensen KF. Development of a Photochemical Microfluidics Platform. J Flow Chem 2011. [DOI: 10.1556/jfchem.2011.00006] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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34
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Goodell JR, Poole JL, Beeler AB, Aubé J, Porco JA. Synthesis and reactivity of bicyclo[3.2.1]octanoid-derived cyclopropanes. J Org Chem 2011; 76:9792-800. [PMID: 22007996 DOI: 10.1021/jo2018922] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Photochemical oxa-di-π-methane rearrangement of bicyclo[3.2.1]octanoid scaffolds affords multifunctional, donor-acceptor cyclopropanes. A related photochemical reaction of an iminium ether substrate uncovered an unprecedented aza-di-π-methane rearrangement of a β,γ-unsaturated iminium. Donor-acceptor cyclopropanes have been evaluated as substrates for reactions generating several new chemotypes.
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Qi J, Beeler AB, Zhang Q, Porco JA. Catalytic enantioselective alkylative dearomatization-annulation: total synthesis and absolute configuration assignment of hyperibone K. J Am Chem Soc 2011; 132:13642-4. [PMID: 20831187 DOI: 10.1021/ja1057828] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The asymmetric total synthesis of the polyprenylated acylphloroglucinol hyperibone K has been achieved using an enantioselective alkylative dearomatization-annulation process. NMR and computational studies were employed to probe the mode of action of a chiral phase-transfer (ion pair) catalyst.
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Goodell JR, Leng B, Snyder TK, Beeler AB, Porco JA. Multidimensional Screening and Methodology Development for Condensations Involving Complex 1,2-Diketones. SYNTHESIS-STUTTGART 2010; 2010:2254-2270. [PMID: 25132691 PMCID: PMC4132846 DOI: 10.1055/s-0029-1218813] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Multidimensional reaction screening employing complex 1,2-cycloheptanediones is described. The studies have enabled the discovery of regioselective, Lewis acid-mediated condensations with substituted ureas and a diastereoselective hydrogenation process which proceeds via an interesting allylpalladium hydride isomerization.
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Kinoshita H, Ingham OJ, Ong WW, Beeler AB, Porco JA. Tandem processes identified from reaction screening: nucleophilic addition to aryl N-phosphinylimines employing La(III)-TFAA activation. J Am Chem Soc 2010; 132:6412-8. [PMID: 20394364 PMCID: PMC2881420 DOI: 10.1021/ja100346w] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Reaction screening of nucleophilic reaction partners for addition to N-diphenylphosphinylimines employing lanthanum(III) triflate as a catalyst and trifluoroacetic anhydride (TFAA) as an activator is reported. A number of tandem processes leading to novel chemotypes including aza-Prins/intramolecular Friedel-Crafts annulations have been identified, and both reaction scope and mechanism further investigated.
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Kota S, Scampavia L, Spicer T, Beeler AB, Takahashi V, Snyder JK, Porco JA, Hodder P, Strosberg AD. A time-resolved fluorescence-resonance energy transfer assay for identifying inhibitors of hepatitis C virus core dimerization. Assay Drug Dev Technol 2010; 8:96-105. [PMID: 20035614 DOI: 10.1089/adt.2009.0217] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Binding of hepatitis C virus (HCV) RNA to core, the capsid protein, results in the formation of the nucleocapsid, the first step in the assembly of the viral particle. A novel assay was developed to discover small molecule inhibitors of core dimerization. This assay is based on time-resolved fluorescence resonance energy transfer (TR-FRET) between anti-tag antibodies labeled with either europium cryptate (Eu) or allophycocyanin (XL-665). The N-terminal 106-residue portion of core protein (core106) was tagged with either glutathione-S-transferase (GST) or a Flag peptide. Tag-free core106 was selected as the reference inhibitor. The assay was used to screen the library of pharmacologically active compounds (LOPAC) consisting of 1,280 compounds and a 2,240-compound library from the Center for Chemical Methodology and Library Development at Boston University (CMLD-BU). Ten of the 28 hits from the primary TR-FRET run were confirmed in a secondary amplified luminescent proximity homogeneous assay (ALPHA screen). One hit was further characterized by dose-response analysis yielding an IC(50) of 9.3 microM. This 513 Da compound was shown to inhibit HCV production in cultured hepatoma cells.
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Goodell JR, McMullen JP, Zaborenko N, Maloney JR, Ho CX, Jensen KF, Porco JA, Beeler AB. Development of an automated microfluidic reaction platform for multidimensional screening: reaction discovery employing bicyclo[3.2.1]octanoid scaffolds. J Org Chem 2009; 74:6169-80. [PMID: 20560568 PMCID: PMC2976622 DOI: 10.1021/jo901073v] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
An automated, silicon-based microreactor system has been developed for rapid, low-volume, multidimensional reaction screening. Use of the microfluidic platform to identify transformations of densely functionalized bicyclo[3.2.1]octanoid scaffolds will be described.
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Han C, Rangarajan S, Voukides AC, Beeler AB, Johnson R, Porco JA. Reaction discovery employing macrocycles: transannular cyclizations of macrocyclic bis-lactams. Org Lett 2009; 11:413-6. [PMID: 19102683 DOI: 10.1021/ol802729f] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Macrocyclic bis-lactams have been synthesized by cyclodimerization of homoallylic amino esters employing a Zr(IV)-catalyzed ester-amide exchange protocol. Base-mediated transannular cyclizations have been identified to access both bicyclic [5-11] and tricyclic [5-8-5] frameworks in good yield and diastereoselectivity. Preliminary mechanistic studies support an olefin isomerization-intramolecular conjugate addition pathway.
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Zhou Y, Beeler AB, Cho S, Wang Y, Franzblau SG, Snyder JK. Library Synthesis Using 5,6,7,8-Tetrahydro-1,6-naphthyridines as Scaffolds. ACTA ACUST UNITED AC 2008; 10:534-40. [DOI: 10.1021/cc800038r] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Ong WW, Beeler AB, Kesavan S, Panek JS, Porco JA. Nucleophilic addition to N-phosphinylimines by rare-earth-metal triflate/trifluoroacetic anhydride activation. Angew Chem Int Ed Engl 2007; 46:7470-2. [PMID: 17722135 DOI: 10.1002/anie.200700694] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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43
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Peng LF, Kim SS, Matchacheep S, Lei X, Su S, Lin W, Runguphan W, Choe WH, Sakamoto N, Ikeda M, Kato N, Beeler AB, Porco JA, Schreiber SL, Chung RT. Identification of novel epoxide inhibitors of hepatitis C virus replication using a high-throughput screen. Antimicrob Agents Chemother 2007; 51:3756-9. [PMID: 17682098 PMCID: PMC2043288 DOI: 10.1128/aac.00233-07] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2007] [Revised: 05/07/2007] [Accepted: 07/28/2007] [Indexed: 11/20/2022] Open
Abstract
Using our high-throughput hepatitis C replicon assay to screen a library of over 8,000 novel diversity-oriented synthesis (DOS) compounds, we identified several novel compounds that regulate hepatitis C virus (HCV) replication, including two libraries of epoxides that inhibit HCV replication (best 50% effective concentration, < 0.5 microM). We then synthesized an analog of these compounds with optimized activity.
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Woo GHC, Beeler AB, Snyder JK. 1,2,3,4-Tetrahydro-1,5-naphthyridines and related heterocyclic scaffolds: Exploration of suitable chemistry for library development. Tetrahedron 2007; 63:5649-5655. [PMID: 19112520 DOI: 10.1016/j.tet.2007.04.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The chemistry of 1,2,3,4-tetrahydro-1,5-naphthyridines and 2,3,4,5-tetrahydro-1H-pyrido[3,2-b]azepines has been explored with the goal of discovering reactions at N1 suitable for library development. Epoxide openings, palladium-catalyzed N-arylations, DEPBT-promoted acylations, and urea formation through the reaction with isocyanates were all successful. The epoxide opening chemistry using homochiral epichlorohydrin, with epoxide reclosure and a second nucleophilic opening led to the preparation of a small 24-membered library.
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45
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Choi SR, Beeler AB, Pradhan A, Watkins EB, Rimoldi JM, Tekwani B, Avery MA. Generation of Oxamic Acid Libraries: Antimalarials and Inhibitors of Plasmodium falciparum Lactate Dehydrogenase. ACTA ACUST UNITED AC 2007; 9:292-300. [PMID: 17316052 DOI: 10.1021/cc060110n] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Lactate dehydrogenase (LDH) is a key enzyme in the glycolytic pathway of Plasmodium falciparum (pf) and has several unique amino acids, related to other LDHs, at the active site, making it an attractive target for antimalarial agents. Oxamate, a competitive inhibitor, shows high substrate affinity for pfLDH. This class of compounds has been viewed as potential antimalarial agents. Thus, we have developed an effective automated synthetic strategy for the rapid synthesis of oxamic acid and ester libraries to screen for potential lead inhibitors. One hundred sixty-seven oxamic acids were synthesized using a "catch and release" method with overall yields of 20-70%. Most of the compounds synthesized had some inhibitory effects, but compounds 5 and 6 were the most active against both chloroquine- and mefloquine-resistant strains with IC50 values of 15.4 and 9.41 microM and 20.4 and 8.40 microM, respectively. Some oxamic acids showed activities against pfLDH and mammalian LDH (mLDH) at the micromolar range. These oxamic acids selectively inhibited pfLDH 2-5 fold over mLDH. Oxamic acid 21 was the most active against pfLDH at IC50 = 14 and mLDH at IC50 = 25 microM, suggesting that oxamic acid derivatives are potential inhibitors of pfLDH and that further study is required to develop selective inhibitors of pfLDH over mLDH.
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Beeler AB, Su S, Singleton CA, Porco JA. Discovery of Chemical Reactions through Multidimensional Screening. J Am Chem Soc 2007; 129:1413-9. [PMID: 17263426 DOI: 10.1021/ja0674744] [Citation(s) in RCA: 176] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Multidimensional reaction screening of ortho-alkynyl benzaldehydes with a variety of catalysts and reaction partners was conducted in an effort to identify new chemical reactions. Reactions affording unique products were selected for investigation of preliminary scope and limitations.
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47
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Dandapani S, Lan P, Beeler AB, Beischel S, Abbas A, Roth BL, Porco JA, Panek JS. Convergent Synthesis of Complex Diketopiperazines Derived from Pipecolic Acid Scaffolds and Parallel Screening against GPCR Targets. J Org Chem 2006; 71:8934-45. [PMID: 17081025 DOI: 10.1021/jo061758p] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A convergent approach to highly functionalized diketopiperazines (DKPs) using enantioenriched pipecolic acids is described. Scandium triflate-catalyzed [4 + 2] aza-annulation was employed to produce stereochemically well-defined building blocks. A resin "catch and release" strategy was devised to convert annulation products to pipecolic acid monomers. Complex diketopiperazines were efficiently assembled utilizing one-pot cyclodimerization of pipecolic acids. Massively parallel screening of the complex DKPs against a panel of molecular targets identified novel ligands for a number of G-protein-coupled receptors (GPCRs).
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48
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Gerard B, Ryan J, Beeler AB, Porco JA. Synthesis of 1,4,5-trisubstituted-1,2,3-triazoles by copper-catalyzed cycloaddition-coupling of azides and terminal alkynes. Tetrahedron 2006. [DOI: 10.1016/j.tet.2006.04.025] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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49
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Beeler AB, Schaus SE, Porco JA. Chemical library synthesis using convergent approaches. Curr Opin Chem Biol 2005; 9:277-84. [PMID: 15939329 DOI: 10.1016/j.cbpa.2005.04.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2005] [Accepted: 04/13/2005] [Indexed: 11/18/2022]
Abstract
New strategies are continuously being developed in combinatorial and diversity-oriented synthesis. Convergent design in target-oriented synthesis is commonly employed for construction of complex molecules. In this mini-review, we describe examples of convergent library design and synthesis as well as potential areas for future development.
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Beeler AB, Acquilano DE, Su Q, Yan F, Roth BL, Panek JS, Porco JA. Synthesis of a Library of Complex Macrodiolides Employing Cyclodimerization of Hydroxy Esters. ACTA ACUST UNITED AC 2005; 7:673-81. [PMID: 16153061 DOI: 10.1021/cc050064b] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The synthesis of complex macrodiolides involving microwave-accelerated transesterification of chiral, nonracemic, hydroxy esters is described. Methodology development studies indicate that both microwave power and reaction temperature play an important role in the efficiency of cyclodimerizations. Hydroxy ester monomer pairs were evaluated using an analytical rehearsal leading to the preparation of a 127-member library of highly diverse and stereochemically well-defined macrodiolides. Preliminary assays identified a novel macrodiolide antagonist of the kappa opioid receptor.
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