1
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Abstract
Traceless solid-phase synthesis represents an ultimate sophisticated synthetic strategy on insoluble supports. Compounds synthesized on solid supports can be released without a trace of the linker that was used to tether the intermediates during the synthesis. Thus, the target products are composed only of the components (atoms, functional groups) inherent to the target core structure. A wide variety of synthetic strategies have been developed to prepare products in a traceless manner, and this review is dedicated to all aspects of traceless solid-phase organic synthesis. Importantly, the synthesis does not need to be carried out on a linker designed for traceless synthesis; most of the synthetic approaches described herein were developed using standard, commercially available linkers (originally devised for solid-phase peptide synthesis). The type of structure prepared in a traceless fashion is not restricted. The individual synthetic approaches are divided into eight sections, each devoted to a different methodology for traceless synthesis. Each section consists of a brief outline of the synthetic strategy followed by a description of individual reported syntheses.
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Affiliation(s)
- Naděžda Cankařová
- Department of Organic Chemistry, Faculty of Science , Palacky University , 17. Listopadu 12 , Olomouc , 771 46 , Czech Republic
| | - Eva Schütznerová
- Department of Organic Chemistry, Faculty of Science , Palacky University , 17. Listopadu 12 , Olomouc , 771 46 , Czech Republic
| | - Viktor Krchňák
- Department of Organic Chemistry, Faculty of Science , Palacky University , 17. Listopadu 12 , Olomouc , 771 46 , Czech Republic.,Department of Chemistry and Biochemistry , University of Notre Dame , 251 Nieuwland Science Center , Notre Dame , Indiana 46556 , United States
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2
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Okorochenkov S, Burglova K, Popa I, Hlavac J. Solid-supported hydrazone of 4-(4'-formyl-3'-methoxyphenoxy)butyric acid as a new traceless linker for solid-phase synthesis. Org Lett 2015; 17:180-3. [PMID: 25536078 DOI: 10.1021/ol5034223] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The use of a hydrazine derived from a backbone amide linker as a new hydrazone-based traceless linker for solid-phase organic synthesis is described. The stability of the linker was tested under various conditions, including treatment with acids, bases, and borohydrides. Final compounds can be released by selective cleavage using trimethylsilanolate. To demonstrate the versatility of the linker, the synthesis of a model compound under various reaction conditions was performed with good results.
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Affiliation(s)
- Sergei Okorochenkov
- Department of Organic Chemistry, Faculty of Science, Palacký University , 771 46 Olomouc, Czech Republic
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3
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Spasov AA, Yakovlev DS, Suzdalev KF, Kosolapov VA, Kucheryavenko AF, Gurova NA, Grechko OY, Naumenko LV, Kolobrodova NA, Mitina TM, Mal’tsev DV, Babakova MN. Synthesis and pharmacological activity of amides of 2-amino-3-indolylacrylic acid. Pharm Chem J 2013. [DOI: 10.1007/s11094-013-0851-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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4
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Abstract
1,4-Benzodiazepin-2-ones have applications in many areas of medicinal chemistry that are not restricted to 'classical' CNS treatments such as sedatives, epilepsy and muscle relaxants. We will describe selected examples of 1,4-benzodiazepin-2-ones in other areas of medicinal chemistry including uses as G-protein-coupled receptor antagonists, enzyme inhibitors and anticancer agents. Examples from our group will mainly show the use of palladacycle complexes of 1,4-benzodiazepin-2-ones as anticancer agents.
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5
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Synthesis of pseudopeptidic (S)-6-amino-5-oxo-1,4-diazepines and (S)-3-benzyl-2-oxo-1,4-benzodiazepines by an Ugi 4CC Staudinger/aza-Wittig sequence. Tetrahedron 2010. [DOI: 10.1016/j.tet.2010.06.062] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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6
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Matsushita K, Okamoto C, Yoshimoto M, Harada K, Kubo M, Fukuyama Y, Hioki H. Novel alkoxyamine linker to load ketones for solid-phase synthesis: application of the synthesis of 1,4-benzodiazepine-2-ones. JOURNAL OF COMBINATORIAL CHEMISTRY 2010; 12:311-4. [PMID: 20205451 DOI: 10.1021/cc9001795] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Kimihito Matsushita
- Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan
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7
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Terauchi T, Machida S, Komba S. A new method for cleavage of silicon–carbon linkers on glass plate supports with applications to solid-phase syntheses on silica resins. Tetrahedron Lett 2010. [DOI: 10.1016/j.tetlet.2010.01.042] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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8
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Yoshida M, Doi T, Kang S, Watanabe J, Takahashi T. Solid-phase combinatorial synthesis of ester-type banana-shaped molecules by sequential palladium-catalyzed carbonylation. Chem Commun (Camb) 2009:2756-8. [DOI: 10.1039/b901788g] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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9
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Laustsen LS, Sams CK. Parallel Synthesis of 1,3-Dihydro-1,4-benzodiazepine-2-ones Employing Catch and Release. ACTA ACUST UNITED AC 2007; 9:1094-103. [DOI: 10.1021/cc0700647] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Line S. Laustsen
- Medicinal Chemistry Research I, Chemical Research, Leo Pharma, Ballerup 2750, Denmark
| | - Christian K. Sams
- Medicinal Chemistry Research I, Chemical Research, Leo Pharma, Ballerup 2750, Denmark
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10
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Jung N, Wiehn M, Bräse S. Multifunctional Linkers for Combinatorial Solid Phase Synthesis. Top Curr Chem (Cham) 2007. [DOI: 10.1007/128_2007_118] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
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11
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Mincheva Z, Bonnette F, Lavastre O. Ionic Liquid Supports Stable Under Conditions of Peptide Couplings, Deprotections and Traceless Suzuki Reactions. ACTA ACUST UNITED AC 2007. [DOI: 10.1135/cccc20070417] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Ionic liquid supports (ILS) functionalized with carboxylic, alcoholic or amino groups were synthesized, based on 1-methylimidazolium and pyridinium cations, and bromide, chloride, iodide and tetrafluoroborate anions. These reactive ionic liquids were fully characterized by NMR and HRMS. Ionic liquids based on 1-(6-aminohexyl)-3-methylimidazolium iodide have been used in the conditions of peptide chemistry such as coupling and deprotection reactions. A method for attaching (bromophenyl)silanes to the ionic liquid supports was also developed to introduce traceless linkers. An ionic liquid with attached bromobenzene was reacted with ArB(OH)2 under the Suzuki cross-coupling conditions and the resulting compound was cleaved by bromodesilylation with Br2/pyridine to give the substituted products in good yields. The substrate loading of the ILS is high and can be tuned to between 2.5 and 5.0 mmol/g.
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12
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Turner DJ, Anémian R, Mackie PR, Cupertino DC, Yeates SG, Turner ML, Spivey AC. Towards a general solid phase approach for the iterative synthesis of conjugated oligomers using a germanium based linker - first solid phase synthesis of an oligo-(triarylamine). Org Biomol Chem 2007; 5:1752-63. [PMID: 17520144 DOI: 10.1039/b703022c] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The development of a germanium-based linker system for the solid phase synthesis (SPS) of 3-(n-hexyl)thiophene oligomers and the first SPS of triarylamine oligomers via iterative chain extension is described. The efficiency of the key steps in the oligomer syntheses and their compatibility with the germanium linker are demonstrated by the SPS of bi-[3-(n-hexyl)thiophene] 19 and ter-(triarylamine) 50. The use of a germanium-based linker in combination with appropriately selected silicon-based blocking/protecting groups allows double coupling to drive the key cross coupling steps to completion hence minimising deletion sequences and also allows for traceless and potentially functionalisative cleavage from the resin. The latter feature has yet to be fully explored but towards this end the first ipso-borodegermylation reaction of a 2-germyl-3-(n-hexyl)thiophene is presented.
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Affiliation(s)
- David J Turner
- Department of Chemistry, University of Sheffield, Brook Hill, Sheffield, UK S3 7HF.
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13
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Verdié P, Subra G, Feliu L, Sanchez P, Bergé G, Garcin G, Martinez J. On-Line Synthesis of Pseudopeptide Library Incorporating a Benzodiazepinone Turn Mimic: Biological Evaluation on MC1 Receptors. ACTA ACUST UNITED AC 2006; 9:254-62. [PMID: 17348731 DOI: 10.1021/cc060054q] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Alpha melanocyte stimulating hormone (alpha-MSH) is a widely distributed hormone. This tridecapeptide exhibits various biological activities mediated through different receptors. alpha-MSH binds to the melanocortin-1 receptor (MC1-R), mainly expressed in keratinocytes and melanocytes, inducing melanogenesis and anti-inflammatory processes. The central His-Phe-Arg-Trp tetrapeptide sequence of alpha-MSH is known to form a turn in the bioactive conformation. To find new potent analogs of alpha-MSH, we decided to introduce non-peptide building blocks in the alpha-MSH sequence. Molecular modeling studies showed that two amino acids of the central core sequence could be replaced by the benzodiazepinone building block without loosing the beta-turn conformation. Benzodiazepines are well-known pharmacophores exhibiting a wide scope of biological activities and are described as constrained dipeptide mimics templates. Although numerous synthetic pathways leading to benzodiazepinones have been described in literature, no methodology has 1,4-benzodiazepine-2,5-diones building blocks bearing a free carboxylic acid function and a protected amino function suitable for incorporation into peptide sequences. In this study, we report the synthesis of peptides with a benzodiazepinone moiety obtained directly during the course of solid-phase peptide synthesis (SPPS). This "on-line" strategy leads to the generation of a 54-member pseudo-peptide library of alpha-MSH analogs. After LC/MS purification, binding assays were performed on the MC1 receptor leading to the discovery of several micromolar ligands.
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Affiliation(s)
- Pascal Verdié
- Laboratoire des Aminoacides, Peptides et Protéines (LAPP), UMR 5810, Faculté de Pharmacie, Université de Montpellier I et II, 15 avenue Charles Flahault, 34060 Montpellier, France
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14
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Affiliation(s)
- Peter J. H. Scott
- Department of Chemistry, University at Buffalo, the State University of New York, Buffalo, NY 14260, USA
| | - Patrick G. Steel
- Department of Chemistry, University of Durham, Durham, DH1 3LE, UK
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15
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Tsukamoto H, Suzuki R, Kondo Y. Revisiting Benzenesulfonyl Linker for the Deoxygenation and Multifunctionalization of Phenols. ACTA ACUST UNITED AC 2006; 8:289-92. [PMID: 16676996 DOI: 10.1021/cc0600066] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Hirokazu Tsukamoto
- Graduate School of Pharmaceutical Sciences, Tohoku University, Aobayama, Aoba-ku, Sendai, Japan.
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16
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Anémian R, Cupertino D, Mackie P, Yeates S. Solution phase studies towards the synthesis of triarylamine oligomers using a germanium linker on a solid support. Tetrahedron Lett 2005. [DOI: 10.1016/j.tetlet.2005.07.150] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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17
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Pierrat P, Gros PC, Fort Y. Solid Phase Synthesis of Pyridine-Based Derivatives from a 2-Chloro-5-Bromopyridine Scaffold. ACTA ACUST UNITED AC 2005; 7:879-86. [PMID: 16283796 DOI: 10.1021/cc050054a] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
2-Chloro-5-bromopyridine was immobilized on polystyrene via selective introduction of a traceless silicon linker at the C-4 position. A useful scaffold was thus obtained, as demonstrated by efficient and selective reactions with polar and transition organometallic reagents, opening a new access to pyridine-based libraries of synthons and chromophores.
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Affiliation(s)
- Philippe Pierrat
- Synthèse Organométallique et Réactivité, UMR 7565, Faculté des Sciences, Université Henri Poincaré, Boulevard des Aiguillettes, BP 239, 54506 Vandoeuvre-lès-Nancy, France
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18
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Gil C, Bräse S. Traceless and multifunctional linkers for the generation of small molecules on solid supports. Curr Opin Chem Biol 2005; 8:230-7. [PMID: 15183320 DOI: 10.1016/j.cbpa.2004.04.004] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Numerous developments in useful linkers are closely related with the advances in solid-phase organic synthesis. These linkers allow facile attachment functionalization and release molecules of interest. Designing a new anchoring group can be essential for synthesis success, especially for small molecules on solid supports. Many novel linkers have recently been developed. Traceless linkers can be excised efficiently and quantitatively when desired while leaving behind no trace of the solid-phase synthesis. However, multi-functional cleavage allows the introduction of new functionalities during cleavage from the resin.
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Affiliation(s)
- Carmen Gil
- Kekulé-Institut für Organische Chemie und Biochemie der Rheinischen, Friedrich-Wilhelms-Universität Bonn, Gerhard-Domagk-Strasse 1, D-53121 Bonn, Germany
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19
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Chemistry of the diboron compounds. ACTA ACUST UNITED AC 2005. [DOI: 10.1016/s0169-3158(06)80002-2] [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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20
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Doi T, Yoshida M, Hijikuro I, Takahashi T. An efficient synthesis of polymer-supported silyl linkers using a di-Grignard reagent. Tetrahedron Lett 2004. [DOI: 10.1016/j.tetlet.2004.05.100] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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21
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Abstract
The first total synthesis of the natural cyclic heptapeptide scytalidamide A was achieved on solid phase using two different resins, a phenylalanine silane resin and a 4-methoxybenzaldehyde backbone linker resin. The synthetic product confirms the structure of the natural product reported in the preceding paper in this issue (Tan, L. T.; Cheng, X. C.; Jensen, P. R.; Fenical, W. J. Org. Chem. 2003, 68, 8767).
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Affiliation(s)
- Wenxin Gu
- Department of Chemistry and Drug Discovery Program, Northwestern University, Evanston, IL 60208-3113, USA
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22
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Spivey AC, Srikaran R, Diaper CM, Turner DJ. Traceless solid phase synthesis of 2-substituted pyrimidines using an 'off-the-shelf' chlorogermane-functionalised resin. Org Biomol Chem 2003; 1:1638-40. [PMID: 12926347 DOI: 10.1039/b303064d] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The parallel solid phase synthesis of an 18-member library of 2-substituted pyrimidines is described using a chlorogermane-functionalised resin. The success of the key Pinner-type condensations between a resin-bound enaminone and an array of amidine hydrochlorides highlights the stability of arylgermane linkers (cf. arylsilanes) towards strongly basic/nucleophilic conditions.
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Affiliation(s)
- Alan C Spivey
- Department of Chemistry, University of Sheffield, Brook Hill, Sheffield, Yorkshire, UK S3 7HF.
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23
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Horton DA, Bourne GT, Smythe ML. The combinatorial synthesis of bicyclic privileged structures or privileged substructures. Chem Rev 2003; 103:893-930. [PMID: 12630855 DOI: 10.1021/cr020033s] [Citation(s) in RCA: 2443] [Impact Index Per Article: 116.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Douglas A Horton
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, 4072 Queensland, Australia
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25
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Swenson RE, Sowin TJ, Zhang HQ. Synthesis of substituted quinolines using the dianion addition of N-Boc-anilines and alpha-tolylsulfonyl-alpha,beta-unsaturated ketones. J Org Chem 2002; 67:9182-5. [PMID: 12492318 DOI: 10.1021/jo0203387] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A short and versatile synthesis of substituted quinolines is provided. Alkylation of sodium tolylsulfinate with bromomethyl- or chloromethyl ketones generates beta-keto sulfones. Knoevenagel condensation of the beta-keto sulfones with an aldehyde provides alpha-tolylsulfonyl-alpha,beta-unsaturated ketones. Michael addition of the dianion of N-Boc-anilines in the presence of CuCN and LiCl with the unsaturated ketone generates a 1,4-adduct, which after deprotection of the Boc group and thermal elimination of the tolyl sulfone provides the quinoline.
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Affiliation(s)
- Rolf E Swenson
- Department of Medicinal Chemistry Technologies (R-4CP), Pharmaceutical Product Division, Abbott Laboratories, Abbott Park, Illinois 60064, USA
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26
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Gu W, Liu S S, Silverman RB. Solid-phase, Pd-catalyzed silicon-aryl carbon bond formation. Synthesis of sansalvamide A peptide. Org Lett 2002; 4:4171-4. [PMID: 12423114 DOI: 10.1021/ol0269392] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A palladium-catalyzed silicon-aryl carbon bond formation on solid-phase is reported. A phenylalanine silane resin was prepared directly from protected iodo-substituted phenylalanine with butyl diethylsilane polystyrene in one step. A rapid and high-yield solid-phase synthesis of sansalvamide A peptide was achieved from the phenylalanine silane resin. [reaction: see text]
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Affiliation(s)
- Wenxin Gu
- Department of Chemistry and Drug Discovery Program, Northwestern University, Evanston, IL 60208-3113, USA
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Bräse S, Gil C, Knepper K. The recent impact of solid-phase synthesis on medicinally relevant benzoannelated nitrogen heterocycles. Bioorg Med Chem 2002; 10:2415-37. [PMID: 12057632 DOI: 10.1016/s0968-0896(02)00025-1] [Citation(s) in RCA: 241] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Benzoannelated heterocycles such as benzodiazepines and indoles can be prepared efficiently through cyclization on solid supports, although no single approach is currently universal for the preparation of all benzoannelated N-heterocycle chemistries. In this review, a number of synthetic strategies for the generation of benzoannelated nitrogen heterocycles using resin-bound substrates have been described. Classical heterocycle forming reactions such as the Fischer indole, the Bischler-Napieralski tetrahydroisoquinoline, the Pictet-Spengler tetrahydro-beta-carboline, the Tsuge, the Nenitzescu and the Richter cinnoline reaction are presented. In addition, the Heck, Sonogashira, Wittig, Diels-Alder, and olefin metathesis reactions have been also used. Multicomponent reactions such as the Grieco three-component assembly have been exploited for the synthesis of heterocycles. Cyclative cleavage from the solid support is particularly suitable for the synthesis of heterocycles while particular emphasis has been focused on the synthesis of libraries and the use of combinatorial chemistry techniques. In addition, the most relevant pharmacological properties of benzoannelated nitrogen heterocycles are included.
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Affiliation(s)
- Stefan Bräse
- Kekulé-Institut für Organische Chemie und Biochemie der Rheinischen Friedrich-Wilhelms-Universität Bonn, Gerhard-Domagk-Strasse 1, D-53121 Bonn, Germany.
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29
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Bräse S, Neuß B. Glossar von Begriffen der Kombinatorischen Chemie. Angew Chem Int Ed Engl 2002. [DOI: 10.1002/1521-3757(20020301)114:5<893::aid-ange893>3.0.co;2-s] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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30
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Affiliation(s)
- Viktor Krchnák
- ChemRx Advanced Technologies, Inc., a Discover Partners International Company, 9040 South Rita Road, Tucson, Arizona 85747, USA.
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Abstract
A traceless linker strategy for the solid-supported synthesis of 5-benzoylbenzimidazoles has been developed. A benzyl cyanide functional group was linked to 2% divinylbenzene cross-linked polystyrene through a dimethylsilyl linker. Coupling with 5-chloro-2-nitroaniline followed by oxidative decyanation gave benzophenone 11 as a key intermediate in an efficient one-pot reaction procedure. After reduction of the nitro group and oxidative cyclization with a variety of aldehydes in the presence of DDQ, a series of polymer-supported benzimidazoles was produced. Final traceless cleavage of the arylsilane linker with TBAF provided a small library of 5-benzoylbenzimidazoles.Key words: solid-support, traceless linker, arylsilane, 5-benzoylbenzimidazole.
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32
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Kumagai T, Itsuno S. Asymmetric allylation polymerization of bis(allylsilane) and dialdehyde containing Siphenyl linkage. ACTA ACUST UNITED AC 2001. [DOI: 10.1016/s0957-4166(01)00445-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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33
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Abstract
4-Bromophenethyl alcohol was protected as the THP ether, followed by reaction with magnesium and selenium to give the corresponding diselenide. Ether deprotection provides a diselenide diol, which is attached to solid-phase resins. The polymer-bound selenide anion is then generated, and functions as a traceless linker for electrophiles such as alkyl halides.
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Affiliation(s)
- Z Li
- Institute of Molecular and Cell Biology, National University of Singapore, 30 Medical Drive, Singapore 117609, Singapore
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34
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Tallarico JA, Depew KM, Pelish HE, Westwood NJ, Lindsley CW, Shair MD, Schreiber SL, Foley MA. An alkylsilyl-tethered, high-capacity solid support amenable to diversity-oriented synthesis for one-bead, one-stock solution chemical genetics. ACTA ACUST UNITED AC 2001; 3:312-8. [PMID: 11350255 DOI: 10.1021/cc000107i] [Citation(s) in RCA: 99] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The synthesis and use of an alkylsilyl-tethered large (500-600 microm) polystyrene resin (1) are disclosed. An optimized Suzuki coupling of bromine-functionalized polystyrene and a silicon-functionalized alkylborane generates the silicon-substituted polystyrene 1 in large scale (>100 g). Resin loading is accomplished by activation as the silyl triflate, which can accommodate even sterically encumbered secondary alcohols and phenols. Treatment with HF/pyridine for linker cleavage is mild, efficient, and amenable to an automated, large-scale distribution system. This platform delivers, minimally, 50 nmol of each small molecule derived from a diversity-oriented, split-pool synthesis on a per bead basis for use in both forward and reverse chemical genetic assays. This technology satisfies many requirements of a one bead-one stock solution approach to chemical genetics.
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Affiliation(s)
- J A Tallarico
- Harvard Institute of Chemistry and Cell Biology (ICCB), Harvard Medical School, 250 Longwood Avenue, Boston, Massachusetts 02115, USA
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35
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Lee Y, Silverman RB. Silicon-based aromatic transferring linkers for traceless solid-phase synthesis of aryl-, polyaryl-, and heteroaryl-containing compounds. Tetrahedron 2001. [DOI: 10.1016/s0040-4020(01)00457-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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37
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Abstract
Nowadays it is rare to find an issue of a major chemistry journal without at least one article on solid-phase synthesis. This is hardly surprising: the technique promises an end to arduous work-up procedures and the ability to facilitate the creation of vast libraries of compounds using combinatorial techniques. No longer is the technique only of interest to those involved in peptide synthesis: an enormous variety of product classes have now been prepared on and isolated from the solid phase. It is the "linker" which is the focus of this article. The linker's ultimate function is to release a product from the support into solution: it does this, without exception, with a chemical change to the product at the former linkage site. Some linkers, apparently, are "traceless". But what, in fact, is "tracelessness"? Twenty years ago, in a climate where cleavage of a linker resulted in formation of a polar carboxylic acid as the vestige of the support, the concept was attractive. Today the chemist is faced with a myriad of novel linkers which have the ability to release products bearing most major functionalities at the former linkage site and we will argue here that the term "traceless", although currently in widespread use, is meaningless. Instead, we propose a new categorization of linkers based on the functionality they release upon cleavage, and suggest a nomenclature to underpin this categorization. We anticipate that the article will also serve to highlight areas of linker technology in need of further research.
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Affiliation(s)
- Alex C. Comely
- Department of Chemistry King's College, London, Strand London, WC2R 2LS (UK)
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38
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Liao Y, Fathi R, Reitman M, Zhang Y, Yang Z. Optimization study of Sonogashira cross-coupling reaction on high-loading macrobeads using a silyl linker. Tetrahedron Lett 2001. [DOI: 10.1016/s0040-4039(01)00052-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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39
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Lee CL, Chan KP, Lam Y, Lee SY. Solid-phase combinatorial synthesis of 1,4-benzoxazin-3(4 H )-one and 1,4-benzothiazin-3(4 H )-one derivatives. Tetrahedron Lett 2001. [DOI: 10.1016/s0040-4039(00)02199-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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40
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Krchňák V, Smith J, Vágner J. Solid-Phase Traceless Synthesis of Selected Nitrogen-Containing Heterocyclic Compounds. The Encore Technique for Directed Sorting of Modular Solid Support. ACTA ACUST UNITED AC 2001. [DOI: 10.1135/cccc20011078] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The acid lability of electron-rich N-benzylanilines has been exploited in a linker for the traceless solid-phase synthesis of benzimidazoles, 2-aminobenzimidazoles, quinoxalinones and tetrahydroquinoxalines. The target compound precursors were assembled on a solid-phase support derivatized with either a benzylamine or a benzhydrylamine linker. Exposure to an acidic reagent caused cleavage of the C(benzyl)-N(aniline) bond, releasing the product with only a hydrogen atom on the descending nitrogen. The Encore technique for directed sorting on SynPhase Lanterns has been developed and applied to combinatorial synthesis of generic drug discovery libraries.
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41
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Lee Y, Silverman RB. Rapid, high-yield, solid-phase synthesis of the antitumor antibiotic sansalvamide A using a side-chain-tethered phenylalanine building block. Org Lett 2000; 2:3743-6. [PMID: 11073690 DOI: 10.1021/ol0002830] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A 10-step solid-phase synthesis of the cytotoxic depsipeptide sansalvamide A (1) has been accomplished in an overall yield of 67% with >95% purity employing polymer-bound phenylalanine building block 2. Both the N- and C-termini of 2 are extended followed by on-resin head-to-tail macrocyclization of the linear peptide in a high yield. This should be a general stategy for the synthesis of diverse libraries of cyclic peptides and depsipeptides that contain exclusively phenylalanine and other hydrophobic side chains.
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Affiliation(s)
- Y Lee
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208-3113, USA
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42
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Tacke R, Ulmer B, Wagner B, Arlt M. A Novel Silicon-Based Linkage and Cleavage Strategy for Solid-Phase Synthesis: Formation of Resin-Linked Zwitterionic Pentacoordinate Silicates as the Key Step and Release of the Target Molecules in a Traceless Fashion. Organometallics 2000. [DOI: 10.1021/om000616x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Reinhold Tacke
- Institut für Anorganische Chemie, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany, and Merck KGaA, Frankfurter Strasse 250, D-64293 Darmstadt, Germany
| | - Bernhard Ulmer
- Institut für Anorganische Chemie, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany, and Merck KGaA, Frankfurter Strasse 250, D-64293 Darmstadt, Germany
| | - Brigitte Wagner
- Institut für Anorganische Chemie, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany, and Merck KGaA, Frankfurter Strasse 250, D-64293 Darmstadt, Germany
| | - Michael Arlt
- Institut für Anorganische Chemie, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany, and Merck KGaA, Frankfurter Strasse 250, D-64293 Darmstadt, Germany
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43
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44
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Dolle RE. Comprehensive survey of combinatorial libraries with undisclosed biological activity: 1992-1997. Mol Divers 2000; 4:233-56. [PMID: 10849900 DOI: 10.1023/a:1009653221320] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- R E Dolle
- Department of Chemistry, Pharmacopeia, Inc., Princeton, NJ 08345, USA.
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45
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Rasta silanes: new silyl resins with novel macromolecular architecture via living free radical polymerization. JOURNAL OF COMBINATORIAL CHEMISTRY 2000; 2:550-9. [PMID: 11029181 DOI: 10.1021/cc000037f] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Heating TEMPO-methyl resin with dialkylsilane styrenes affords larger resin beads via living free radical polymerization. The new silyl resins prepared by this solvent-free suspension polymerization protocol have been coined "Rasta silanes". Rasta silanes have a novel macromolecular architecture typified by long straight chain polymers bearing the silanes which emanate from the phenyl rings of a cross-linked polystyrene core. By careful selection of comonomers during the polymerization step, loading capacity, silane spacing, and the relative distance of the silane moieties from the resin core can be controlled. The consistently high-loading Rasta silane resins produced can be easily converted into either a reactive silyl chloride or triflate to subsequently anchor alcohols and phenols to the solid phase. Cleavage from the resin can be mediated by treatment with HF.pyridine, TFA solutions, or TBAF.
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46
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A new germanium-based linker for solid phase synthesis of aromatics: synthesis of a pyrazole library. J Org Chem 2000; 65:5253-63. [PMID: 10993354 DOI: 10.1021/jo000401x] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
An efficient synthesis of chlorogermane linker 12 is described. Economic introduction of germanium into this linker is accomplished by insertion of dichlorogermylene [from germanium(IV) chloride] into the homobenzylic C-Cl bond of 4-(2-chloroethyl)phenol 1. Using linker 12, transmetalation with lithiated 4-acetophenone, 3-acetophenone, and 4-(4'methoxy)biphenyl followed by Mitsunobu-type coupling to Argogel gives functionalized resins 14, 16, and 18, respectively. Treatment of resin 18 with TFA, ICl, Br2, or NCS effects clean ipso-degermylation releasing biphenyls 19-22, respectively. Resins 14 and 16 are employed for the parallel synthesis of a library of pyrazoles by enaminone formation (using Bredereck's reagent), condensative ring-closure (using a series of monosubstituted hydrazines), and cleavage (using TFA and Br2). Analysis of this library reveals the influence of the hydrazine substituent on both the regioselectivity of ring-closure and the propensity for electrophilic substitution at the 4-position of the pyrazoles during ipso-degermylative cleavage.
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47
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Franzén R. The Suzuki, the Heck, and the Stille reaction - three versatile methods for the introduction of new C-C bonds on solid support. CAN J CHEM 2000. [DOI: 10.1139/v00-089] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Metal-catalyzed coupling reactions are very efficient and reliable methods for the introduction of new carbon-carbon bonds onto molecules attached to a solid support. This review summarizes recent advances in utilizing the three most used methods, the Suzuki reaction, the Heck reaction, and the Stille reaction, in the field of solid phase organic synthesis resulting in small organic molecule libraries.Key words: metal-catalyzed coupling reactions, carbon-carbon bonds, solid phase synthesis, combinatorial chemistry, drug discovery.
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48
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Guillier F, Orain D, Bradley M. Linkers and cleavage strategies in solid-phase organic synthesis and combinatorial chemistry. Chem Rev 2000; 100:2091-158. [PMID: 11749285 DOI: 10.1021/cr980040+] [Citation(s) in RCA: 389] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- F Guillier
- Department of Chemistry, Southampton University, Highfield, Southampton SO17 1BJ, U.K., and Alanex Division of Agouron Pharmaceuticals, A Werner Lambert Company, 3550 General Atomic Courts, San Diego, California 92121
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49
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Floyd CD, Leblanc C, Whittaker M. Combinatorial chemistry as a tool for drug discovery. PROGRESS IN MEDICINAL CHEMISTRY 2000; 36:91-168. [PMID: 10818672 DOI: 10.1016/s0079-6468(08)70046-8] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The question 'will combinatorial chemistry deliver real medicines' has been posed [96]. First it is important to realise that the chemical part of the drug discovery process cannot stand alone; the integration of synthesis and biological assays is fundamental to the combinatorial approach. The results presented in Tables 3.1 to 3.8 suggest that so far smaller directed combinatorial libraries have obtained equivalent results to those obtained previously from traditional medicinal chemistry analogue programs. Unfortunately, because of the long time it takes to develop pharmaceutical drugs there are no examples yet of marketed drugs discovered by combinatorial methods. There are interesting examples where active leads have been discovered from the screening of the same library against multiple targets (e.g. libraries 13, 39, 43, 66, 71 and 76). It is now possible to handle much larger libraries of non-oligomeric structures and the chemistry required for such applications is becoming available. Whether combinatorial approaches can also be adapted to deal with all the other requirements of a successful pharmaceutical (lack of toxicity, bioavailability etc.) is open to question but there are already examples such as cassette dosing [235-237]. However we can still be optimistic about the possibility of larger libraries producing avenues of investigation for the medicinal chemist to develop into real drugs. Combinatorial chemistry is an important tool for the medicinal chemist.
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Affiliation(s)
- C D Floyd
- British Biotech Pharmaceuticals Limited, Oxford, U.K
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50
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Franzén RG. Recent advances in the preparation of heterocycles on solid support: a review of the literature. JOURNAL OF COMBINATORIAL CHEMISTRY 2000; 2:195-214. [PMID: 10827923 DOI: 10.1021/cc000002f] [Citation(s) in RCA: 247] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- R G Franzén
- Department of Pharmacy, Division of Pharmaceutical Chemistry, University of Helsinki, P.O. Box 56, FIN-00014 Helsinki, Finland
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