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Frankowski KJ, Liu R, Milligan GL, Moeller KD, Aubé J. Practical Electrochemical Anodic Oxidation of Polycyclic Lactams for Late Stage Functionalization. Angew Chem Int Ed Engl 2015; 54:10555-8. [PMID: 26371961 PMCID: PMC4629799 DOI: 10.1002/anie.201504775] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Revised: 06/12/2015] [Indexed: 01/01/2023]
Abstract
Electrochemistry provides a powerful tool for the late-stage functionalization of complex lactams. A two-stage protocol for converting lactams, many of which can be prepared through the intramolecular Schmidt reaction of keto azides, is presented. In the first step, anodic oxidation in MeOH using a repurposed power source provides a convenient route to lactams bearing a methoxy group adjacent to nitrogen. Treatment of these intermediates with a Lewis acid in dichloromethane permits the regeneration of a reactive acyliminium ion that is then reacted with a range of nucleophilic species.
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Affiliation(s)
- Kevin J Frankowski
- Department of Medicinal Chemistry, University of Kansas, 2034 Becker Drive, Lawrence, KS 66047 (USA)
- Present address: Division of Chemical Biology and Medicinal Chemistry and the Center for Integrative Chemical Biology and Drug Discovery, UNC Eshelman School of Pharmacy, University of North Carolina, North Carolina, 27599, USA
| | - Ruzhang Liu
- Department of Medicinal Chemistry, University of Kansas, 2034 Becker Drive, Lawrence, KS 66047 (USA)
| | - Gregory L Milligan
- Department of Chemistry, Saint Martin's University, 5000 Abbey Way, Lacey, WA 98503 (USA)
| | - Kevin D Moeller
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130 (USA)
| | - Jeffrey Aubé
- Department of Medicinal Chemistry, University of Kansas, 2034 Becker Drive, Lawrence, KS 66047 (USA).
- Present address: Division of Chemical Biology and Medicinal Chemistry and the Center for Integrative Chemical Biology and Drug Discovery, UNC Eshelman School of Pharmacy, University of North Carolina, North Carolina, 27599, USA.
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52
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Frankowski KJ, Liu R, Milligan GL, Moeller KD, Aubé J. Practical Electrochemical Anodic Oxidation of Polycyclic Lactams for Late Stage Functionalization. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201504775] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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53
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Ley SV, Fitzpatrick DE, Myers RM, Battilocchio C, Ingham RJ. Machine-Assisted Organic Synthesis. Angew Chem Int Ed Engl 2015; 54:10122-36. [PMID: 26193360 PMCID: PMC4834626 DOI: 10.1002/anie.201501618] [Citation(s) in RCA: 164] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Indexed: 12/11/2022]
Abstract
In this Review we describe how the advent of machines is impacting on organic synthesis programs, with particular emphasis on the practical issues associated with the design of chemical reactors. In the rapidly changing, multivariant environment of the research laboratory, equipment needs to be modular to accommodate high and low temperatures and pressures, enzymes, multiphase systems, slurries, gases, and organometallic compounds. Additional technologies have been developed to facilitate more specialized reaction techniques such as electrochemical and photochemical methods. All of these areas create both opportunities and challenges during adoption as enabling technologies.
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Affiliation(s)
- Steven V Ley
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW (UK).
| | - Daniel E Fitzpatrick
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW (UK)
| | - Rebecca M Myers
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW (UK)
| | - Claudio Battilocchio
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW (UK)
| | - Richard J Ingham
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW (UK)
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54
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Ley SV, Fitzpatrick DE, Myers RM, Battilocchio C, Ingham RJ. Maschinengestützte organische Synthese. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201501618] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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55
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Green RA, Pletcher D, Leach SG, Brown RCD. N-Heterocyclic Carbene-Mediated Oxidative Electrosynthesis of Esters in a Microflow Cell. Org Lett 2015; 17:3290-3. [DOI: 10.1021/acs.orglett.5b01459] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Robert A. Green
- Department
of Chemistry, University of Southampton, Southampton, Hampshire SO17 1BJ, U.K
| | - Derek Pletcher
- Department
of Chemistry, University of Southampton, Southampton, Hampshire SO17 1BJ, U.K
| | | | - Richard C. D. Brown
- Department
of Chemistry, University of Southampton, Southampton, Hampshire SO17 1BJ, U.K
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56
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Patil P, Khoury K, Herdtweck E, Dömling A. MCR synthesis of a tetracyclic tetrazole scaffold. Bioorg Med Chem 2015; 23:2699-715. [PMID: 25630499 PMCID: PMC4733496 DOI: 10.1016/j.bmc.2014.12.021] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Revised: 12/10/2014] [Accepted: 12/11/2014] [Indexed: 11/27/2022]
Abstract
Scaffold diversity is key in the ongoing exercise of discovery of novel bioactive compounds using high throughput screening (HTS). Based on the Ugi tetrazole synthesis we have designed novel bi- and tri-cyclic scaffolds featuring interesting pharmacophore properties. The compounds of the scaffold (B) are synthesizable in large diversity and numbers in two steps using (hetero)phenylethylamines, HN3, oxo components and iscyanoacetaldehyde(dimethylacetale). The chemistry is amenable to parallel synthesis and is used to enhance and fill the screening decks of the European Lead factory (ELF). Here, we are reporting full experimental details, scope and limitations of the reaction, cheminformatic analysis and the 3D structures of selected compounds.
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Affiliation(s)
- Pravin Patil
- Department of Drug Design, University of Groningen, A. Deusinglaan 1, Groningen 9700 AD, The Netherlands
| | | | | | - Alexander Dömling
- Department of Drug Design, University of Groningen, A. Deusinglaan 1, Groningen 9700 AD, The Netherlands.
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57
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Luo YC, Pan XJ, Yuan GQ. An efficient electrochemical synthesis of vinyl sulfones from sodium sulfinates and olefins. Tetrahedron 2015. [DOI: 10.1016/j.tet.2015.02.048] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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58
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Takayama M. Application of Flow Micro Synthesis Technology for Medicinal Chemistry. J SYN ORG CHEM JPN 2015. [DOI: 10.5059/yukigoseikyokaishi.73.504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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59
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Baumann M, Rodriguez Garcia AM, Baxendale IR. Flow synthesis of ethyl isocyanoacetate enabling the telescoped synthesis of 1,2,4-triazoles and pyrrolo-[1,2-c]pyrimidines. Org Biomol Chem 2015; 13:4231-9. [DOI: 10.1039/c5ob00245a] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The efficient flow synthesis of important heterocyclic building blocks based on the 1,2,4-triazole and pyrrolo[1,2-c]pyrimidine scaffold has been achieved.
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60
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Kamptmann SB, Ley SV. Facilitating Biomimetic Syntheses of Borrerine Derived Alkaloids by Means of Flow-Chemical Methods. Aust J Chem 2015. [DOI: 10.1071/ch14530] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Flow chemistry is widely used nowadays in synthetic chemistry and has increasingly been applied to complex natural product synthesis. However, to date flow chemistry has not found a place in the area of biomimetic synthesis. Here we show the syntheses of borrerine derived alkaloids, indicating that we can use biomimetic principles in flow to prepare complex architectures in a single step.
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61
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Jones AM, Banks CE. The Shono-type electroorganic oxidation of unfunctionalised amides. Carbon-carbon bond formation via electrogenerated N-acyliminium ions. Beilstein J Org Chem 2014; 10:3056-72. [PMID: 25670975 PMCID: PMC4311756 DOI: 10.3762/bjoc.10.323] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Accepted: 12/05/2014] [Indexed: 11/23/2022] Open
Abstract
N-acyliminium ions are useful reactive synthetic intermediates in a variety of important carbon–carbon bond forming and cyclisation strategies in organic chemistry. The advent of an electrochemical anodic oxidation of unfunctionalised amides, more commonly known as the Shono oxidation, has provided a complementary route to the C–H activation of low reactivity intermediates. In this article, containing over 100 references, we highlight the development of the Shono-type oxidations from the original direct electrolysis methods, to the use of electroauxiliaries before arriving at indirect electrolysis methodologies. We also highlight new technologies and techniques applied to this area of electrosynthesis. We conclude with the use of this electrosynthetic approach to challenging syntheses of natural products and other complex structures for biological evaluation discussing recent technological developments in electroorganic techniques and future directions.
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Affiliation(s)
- Alan M Jones
- Manchester Metropolitan University, Faculty of Science and Engineering, School of Science and the Environment, Division of Chemistry and Environmental Science, John Dalton Building, Chester Street, Manchester, M1 5GD, UK
| | - Craig E Banks
- Manchester Metropolitan University, Faculty of Science and Engineering, School of Science and the Environment, Division of Chemistry and Environmental Science, John Dalton Building, Chester Street, Manchester, M1 5GD, UK
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