1
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Choi A, Das A, Meijer AJHM, Proietti Silvestri I, Coldham I. Synthesis of enantioenriched spirocyclic 2-arylpiperidines via kinetic resolution. Org Biomol Chem 2024; 22:1602-1607. [PMID: 38314915 DOI: 10.1039/d4ob00011k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2024]
Abstract
Kinetic resolution of N-Boc-spirocyclic 2-arylpiperidines with spiro substitution at C-4 was achieved with high enantiomeric ratios using the chiral base n-BuLi/sparteine. Cyclopropanation or metallaphotoredox catalysis were used to access the piperidines, which could be further functionalised without loss of enantiopurity, highlighting their use as potential 3D fragments for drug discovery.
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Affiliation(s)
- Anthony Choi
- Department of Chemistry, University of Sheffield, Sheffield S3 7HF, UK.
| | - Anjan Das
- Department of Chemistry, University of Sheffield, Sheffield S3 7HF, UK.
| | | | | | - Iain Coldham
- Department of Chemistry, University of Sheffield, Sheffield S3 7HF, UK.
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2
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Yeo S, Choi A, Greaves S, Meijer AJHM, Silvestri IP, Coldham I. Kinetic Resolution of 2-Aryldihydroquinolines Using Lithiation - Synthesis of Chiral 1,2- and 1,4-Dihydroquinolines. Chemistry 2023; 29:e202300815. [PMID: 37067465 PMCID: PMC10946909 DOI: 10.1002/chem.202300815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 04/12/2023] [Accepted: 04/17/2023] [Indexed: 04/18/2023]
Abstract
Highly enantiomerically enriched dihydrohydroquinolines were prepared in two steps from quinoline. Addition of aryllithiums to quinoline with tert-butoxycarbonyl (Boc) protection gave N-Boc-2-aryl-1,2-dihydroquinolines. These were treated with n-butyllithium and electrophilic trapping occurred exclusively at C-4 of the dihydroquinoline, a result supported by DFT studies. Variable temperature NMR spectroscopy gave kinetic data for the barrier to rotation of the carbonyl group (ΔG≠ ≈49 kJ mol-1 , 195 K). Lithiation using the diamine sparteine allowed kinetic resolutions with high enantioselectivities (enantiomer ratio up to 99 : 1). The enantioenriched 1,2-dihydroquinolines could be converted to 1,4-dihydroquinolines with retention of stereochemistry. Further functionalisation led to trisubstituted products. Reduction provided enantioenriched tetrahydroquinolines, whereas acid-promoted removal of Boc led to quinolines, and this was applied to a synthesis of the antimalarial compound M5717.
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Affiliation(s)
- Song‐Hee Yeo
- Department of ChemistryUniversity of SheffieldBrook HillSheffieldS3 7HFUK
| | - Anthony Choi
- Department of ChemistryUniversity of SheffieldBrook HillSheffieldS3 7HFUK
| | - Sophie Greaves
- Department of ChemistryUniversity of SheffieldBrook HillSheffieldS3 7HFUK
| | | | | | - Iain Coldham
- Department of ChemistryUniversity of SheffieldBrook HillSheffieldS3 7HFUK
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3
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Das A, Choi A, Coldham I. Photocatalysis and Kinetic Resolution by Lithiation to Give Enantioenriched 2-Arylpiperazines. Org Lett 2023; 25:987-991. [PMID: 36735675 PMCID: PMC9942196 DOI: 10.1021/acs.orglett.3c00074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Piperazines are important heterocycles in drug compounds. We report the asymmetric synthesis of arylpiperazines by photocatalytic decarboxylative arylation (metallaphotoredox catalysis) then kinetic resolution using n-BuLi/(+)-sparteine. This gave a range of piperazines with very high enantioselectivities. Further functionalizations gave enantioenriched 2,2-disubstituted piperazines, and either N-substituent can be removed selectively. Late-stage functionalizations of enantioenriched piperazine derivatives were demonstrated, including synthesis of a drug compound with glycogen synthase kinase (GSK)-3β inhibitor activity with potential for treating Alzheimer's disease.
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4
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Choi A, Meijer AJHM, Silvestri IP, Coldham I. Kinetic Resolution of 2-Aryl-4-methylenepiperidines toward Enantioenriched Functionalizable Piperidine Fragments. J Org Chem 2022; 87:8819-8823. [PMID: 35699313 PMCID: PMC9490820 DOI: 10.1021/acs.joc.2c00862] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
![]()
The
base n-BuLi with sparteine allows a kinetic
resolution of N-Boc-2-aryl-4-methylenepiperidines.
The 2,2-disubstituted products and recovered starting materials were
isolated with high enantiomeric ratios. From VT-NMR spectroscopy and
DFT studies, the rate of rotation of the N-Boc group
is fast. Lithiation and trapping of the enantioenriched starting materials
gave 2,2-disubstituted piperidines with retention of stereochemistry.
Functionalization of the 4-methylene group led to a variety of 2,4-disubstituted
piperidines without loss of enantiopurity that could be useful building
blocks for drug discovery.
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Affiliation(s)
- Anthony Choi
- Department of Chemistry, University of Sheffield, Brook Hill, Sheffield S3 7HF, U.K
| | - Anthony J H M Meijer
- Department of Chemistry, University of Sheffield, Brook Hill, Sheffield S3 7HF, U.K
| | | | - Iain Coldham
- Department of Chemistry, University of Sheffield, Brook Hill, Sheffield S3 7HF, U.K
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5
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Coldham I, El-Tunsi A, Carter N, Yeo SH, Priest JD, Choi A, Kobras CM, Ndlovu S, Proietti Silvestri I, Fenton AK. Kinetic Resolution by Lithiation: Highly Enantioselective Synthesis of Substituted Dihydrobenzoxazines and Tetrahydroquinoxalines. SYNTHESIS-STUTTGART 2022. [DOI: 10.1055/a-1638-2478] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
AbstractKinetic resolution provided a highly enantioselective method to access a range of 3-aryl-3,4-dihydro-2H-1,4-benzoxazines using n-butyllithium and the chiral ligand sparteine. The enantioenrichment remained high on removing the tert-butoxycarbonyl (Boc) protecting group. The intermediate organolithium undergoes ring opening to an enamine. The kinetic resolution was extended to give enantiomerically enriched substituted 1,2,3,4-tetrahydroquinoxalines and was applied to the synthesis of an analogue of the antibiotic levofloxacin that was screened for its activity against the human pathogen Streptococcus pneumoniae.
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Affiliation(s)
- Iain Coldham
- Department of Chemistry, University of Sheffield
| | | | | | - Song-Hee Yeo
- Department of Chemistry, University of Sheffield
| | | | - Anthony Choi
- Department of Chemistry, University of Sheffield
| | - Carolin M. Kobras
- The Florey Institute, Department of Molecular Biology and Biotechnology, University of Sheffield
| | | | | | - Andrew K. Fenton
- The Florey Institute, Department of Molecular Biology and Biotechnology, University of Sheffield
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6
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Choi A, El‐Tunsi A, Wang Y, Meijer AJHM, Li J, Li X, Proietti Silvestri I, Coldham I. Asymmetric Synthesis of 2-Arylindolines and 2,2-Disubstituted Indolines by Kinetic Resolution. Chemistry 2021; 27:11670-11675. [PMID: 34110662 PMCID: PMC8456874 DOI: 10.1002/chem.202101248] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Indexed: 01/18/2023]
Abstract
Kinetic resolution of 2-arylindolines (2,3-dihydroindoles) was achieved by treatment of their N-tert-butoxycarbonyl (Boc) derivatives with n-butyllithium and sparteine in toluene at -78 °C followed by electrophilic quench. The unreacted starting materials together with the 2,2-disubstituted products could be isolated with high enantiomer ratios. Variable temperature NMR spectroscopy showed that the rate of Boc rotation was fast (ΔG≠ ≈57 kJ/mol at 195 K). This was corroborated by DFT studies and by in situ ReactIR spectroscopy. The enantioenriched N-Boc-2-arylindolines were converted to 2,2-disubstituted products without significant loss in enantiopurity. Hence, either enantiomer of the 2,2-disubstituted products could be obtained with high selectivity from the same enantiomer of the chiral ligand sparteine (one from the kinetic resolution and the other from subsequent lithiation-trapping of the recovered starting material). Secondary amine products were prepared by removing the Boc group with acid to provide a way to access highly enantioenriched 2-aryl and 2,2-disubstituted indolines.
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Affiliation(s)
- Anthony Choi
- Department of ChemistryUniversity of Sheffield Brook HillSheffieldS3 7HFUK
| | - Ashraf El‐Tunsi
- Department of ChemistryUniversity of Sheffield Brook HillSheffieldS3 7HFUK
| | - Yuhang Wang
- Department of ChemistryUniversity of Sheffield Brook HillSheffieldS3 7HFUK
| | | | - Jia Li
- School of Chemistry and Chemical EngineeringShaanxi Normal UniversityXi'an710062PR China
| | - Xiabing Li
- School of Chemistry and Chemical EngineeringShaanxi Normal UniversityXi'an710062PR China
| | | | - Iain Coldham
- Department of ChemistryUniversity of Sheffield Brook HillSheffieldS3 7HFUK
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7
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Jayavelu AK, Schnöder TM, Perner F, Herzog C, Meiler A, Krishnamoorthy G, Huber N, Mohr J, Edelmann-Stephan B, Austin R, Brandt S, Palandri F, Schröder N, Isermann B, Edlich F, Sinha AU, Ungelenk M, Hübner CA, Zeiser R, Rahmig S, Waskow C, Coldham I, Ernst T, Hochhaus A, Jilg S, Jost PJ, Mullally A, Bullinger L, Mertens PR, Lane SW, Mann M, Heidel FH. Splicing factor YBX1 mediates persistence of JAK2-mutated neoplasms. Nature 2020; 588:157-163. [PMID: 33239784 DOI: 10.1038/s41586-020-2968-3] [Citation(s) in RCA: 75] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Accepted: 09/15/2020] [Indexed: 11/09/2022]
Abstract
Janus kinases (JAKs) mediate responses to cytokines, hormones and growth factors in haematopoietic cells1,2. The JAK gene JAK2 is frequently mutated in the ageing haematopoietic system3,4 and in haematopoietic cancers5. JAK2 mutations constitutively activate downstream signalling and are drivers of myeloproliferative neoplasm (MPN). In clinical use, JAK inhibitors have mixed effects on the overall disease burden of JAK2-mutated clones6,7, prompting us to investigate the mechanism underlying disease persistence. Here, by in-depth phosphoproteome profiling, we identify proteins involved in mRNA processing as targets of mutant JAK2. We found that inactivation of YBX1, a post-translationally modified target of JAK2, sensitizes cells that persist despite treatment with JAK inhibitors to apoptosis and results in RNA mis-splicing, enrichment for retained introns and disruption of the transcriptional control of extracellular signal-regulated kinase (ERK) signalling. In combination with pharmacological JAK inhibition, YBX1 inactivation induces apoptosis in JAK2-dependent mouse and primary human cells, causing regression of the malignant clones in vivo, and inducing molecular remission. This identifies and validates a cell-intrinsic mechanism whereby differential protein phosphorylation causes splicing-dependent alterations of JAK2-ERK signalling and the maintenance of JAK2V617F malignant clones. Therapeutic targeting of YBX1-dependent ERK signalling in combination with JAK2 inhibition could thus eradicate cells harbouring mutations in JAK2.
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Affiliation(s)
| | - Tina M Schnöder
- Innere Medizin II, Hämatologie und Onkologie, Universitätsklinikum Jena, Jena, Germany.,Innere Medizin C, Universitätsmedizin Greifswald, Greifswald, Germany
| | - Florian Perner
- Innere Medizin II, Hämatologie und Onkologie, Universitätsklinikum Jena, Jena, Germany
| | - Carolin Herzog
- Department of Haematology and Oncology, Center of Internal Medicine, Otto von Guericke University Medical Center, Magdeburg, Germany
| | - Arno Meiler
- Max Planck Institute of Biochemistry, Munich, Germany
| | | | - Nicolas Huber
- Innere Medizin II, Hämatologie und Onkologie, Universitätsklinikum Jena, Jena, Germany
| | - Juliane Mohr
- Innere Medizin II, Hämatologie und Onkologie, Universitätsklinikum Jena, Jena, Germany
| | - Bärbel Edelmann-Stephan
- Department of Haematology and Oncology, Center of Internal Medicine, Otto von Guericke University Medical Center, Magdeburg, Germany
| | - Rebecca Austin
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia.,Cancer Care Services, Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia.,University of Queensland, Brisbane, Queensland, Australia
| | - Sabine Brandt
- Department of Nephrology and Endocrinology, Center of Internal Medicine, Otto von Guericke University Medical Center, Magdeburg, Germany
| | | | | | - Berend Isermann
- Institute for Clinical Chemistry and Pathobiochemistry, Center of Internal Medicine, Otto von Guericke University Medical Center, Magdeburg, Germany
| | - Frank Edlich
- Institute for Biochemistry and Molecular Biology, University of Freiburg, Freiburg, Germany.,Faculty of Biology, University of Freiburg, Freiburg, Germany.,BIOSS, Centre for Biological Signaling Studies, Freiburg, Germany
| | | | - Martin Ungelenk
- Institut für Humangenetik, Universitätsklinikum Jena, Jena, Germany
| | | | - Robert Zeiser
- Faculty of Biology, University of Freiburg, Freiburg, Germany.,Department of Hematology and Oncology, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Susann Rahmig
- Leibniz Institute on Aging, Fritz Lipmann Institute, Jena, Germany.,Immunology of Aging, Leibniz Institute on Aging, Fritz Lipmann Institute, Jena, Germany
| | - Claudia Waskow
- Leibniz Institute on Aging, Fritz Lipmann Institute, Jena, Germany.,Immunology of Aging, Leibniz Institute on Aging, Fritz Lipmann Institute, Jena, Germany.,Faculty of Biological Sciences, Friedrich Schiller University Jena, Jena, Germany
| | - Iain Coldham
- Department of Chemistry, University of Sheffield, Sheffield, UK
| | - Thomas Ernst
- Innere Medizin II, Hämatologie und Onkologie, Universitätsklinikum Jena, Jena, Germany
| | - Andreas Hochhaus
- Innere Medizin II, Hämatologie und Onkologie, Universitätsklinikum Jena, Jena, Germany
| | - Stefanie Jilg
- Medical Department III for Haematology and Oncology, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - Philipp J Jost
- Medical Department III for Haematology and Oncology, Klinikum rechts der Isar, Technische Universität München, Munich, Germany.,Division of Oncology, Department of Internal Medicine, Medical University of Graz (MUG), Graz, Austria
| | - Ann Mullally
- Division of Hematology, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Lars Bullinger
- Clinic for Hematology, Oncology and Tumor Immunology, Charite University, Berlin, Germany
| | - Peter R Mertens
- Department of Nephrology and Endocrinology, Center of Internal Medicine, Otto von Guericke University Medical Center, Magdeburg, Germany
| | - Steven W Lane
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia.,Cancer Care Services, Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia.,University of Queensland, Brisbane, Queensland, Australia
| | - Matthias Mann
- Max Planck Institute of Biochemistry, Munich, Germany.
| | - Florian H Heidel
- Innere Medizin II, Hämatologie und Onkologie, Universitätsklinikum Jena, Jena, Germany. .,Innere Medizin C, Universitätsmedizin Greifswald, Greifswald, Germany. .,Leibniz Institute on Aging, Fritz Lipmann Institute, Jena, Germany.
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8
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Aggarwal VK, Armstrong SK, Caggiano L, Chibale K, Clayden J, Coldham I, Greeves N, Hartley RC, Knight JG, Kuhnert N, Mitchell HJ, Nelson A, O'Brien P, Thomas SP, Wyatt P. Stuart Warren (24 Dec 1938-22 Mar 2020). Org Biomol Chem 2020. [PMID: 32936190 DOI: 10.1039/d0ob90121k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Celebrating the life of Stuart Warren.
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Affiliation(s)
| | | | - Lorenzo Caggiano
- Department of Pharmacy and Pharmacology, University of Bath, Bath, BA2 7AY, UK.
| | - Kelly Chibale
- Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa.
| | - Jonathan Clayden
- School of Chemistry, University of Bristol, Bristol BS8 1TS, UK.
| | - Iain Coldham
- Department of Chemistry, University of Sheffield, Sheffield S3 7HF, UK.
| | - Nicholas Greeves
- Department of Chemistry, University of Liverpool, Donnan and Robert Robinson Laboratories, Crown Street, Liverpool L69 7ZD, UK.
| | | | - Julian G Knight
- School of Natural and Environmental Sciences (Chemistry), Newcastle University, Newcastle upon Tyne, NE1 7RU, UK.
| | - Nikolai Kuhnert
- Department of Life Science and Chemistry, Jacobs University Bremen, Campusring 8, 28759 Bremen, Germany.
| | - Helen J Mitchell
- International Education Institute, University of St Andrews, Kinnessburn, Kennedy Gardens, St Andrews KY16 9DJ, UK and School of Chemistry, University of St Andrews, Purdie Building, North Haugh, St Andrews KY16 9ST, UK.
| | - Adam Nelson
- School of Chemistry, University of Leeds, Leeds LS2 9JT, UK.
| | - Peter O'Brien
- Department of Chemistry, University of York, York, YO10 5DD, UK.
| | - Stephen P Thomas
- School of Chemistry, University of Edinburgh, Joseph Black Building, David Brewster Road, Edinburgh EH9 3FJ, UK.
| | - Paul Wyatt
- School of Chemistry, University of Bristol, Bristol BS8 1TS, UK.
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9
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Choi A, Castle J, Saruengkhanphasit R, Coldham I. Synthesis of Spirocyclic Amines by 1,3-Dipolar Cycloaddition of Azomethine Ylides and Azomethine Imines. SYNTHESIS-STUTTGART 2020. [DOI: 10.1055/s-0039-1691588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Simple ketone starting materials with a halide leaving group and an alkene were prepared in one step and heated with glycine or glycine esters to promote a tandem imine formation, cyclization, and dipolar cycloaddition cascade. The chemistry was also feasible with acetylhydrazide. In each case a single stereoisomer of the tricyclic amine or pyrazolidine product was formed and the stereochemistry was verified by single crystal X-ray diffraction. When the reaction with glycine, which occurs with loss of CO2, was unsuccessful, the cascade process could be promoted by cross metathesis to give the vinyl sulfone starting material that provides a more reactive dipolarophile. Reductive cleavage of the pyrazolidine gave a spirocyclic diamine product.
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Affiliation(s)
| | | | | | - Iain Coldham
- Department of Chemistry, University of Sheffield
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10
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Choi A, Coldham I. Three-component couplings for the synthesis of pyrroloquinoxalinones by azomethine ylide 1,3-dipolar cycloaddition chemistry. Tetrahedron Lett 2019. [DOI: 10.1016/j.tetlet.2019.151023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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11
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Choi A, Morley RM, Coldham I. Synthesis of pyrrolo[1,2- a]quinolines by formal 1,3-dipolar cycloaddition reactions of quinolinium salts. Beilstein J Org Chem 2019; 15:1480-1484. [PMID: 31354865 PMCID: PMC6633155 DOI: 10.3762/bjoc.15.149] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 06/27/2019] [Indexed: 12/14/2022] Open
Abstract
Quinolinium salts, Q+-CH2-CO2Me Br− and Q+-CH2-CONMe2 Br− (where Q = quinoline), were prepared from quinolines. Deprotonation of these salts with triethylamine promoted the reaction of the resulting quinolinium ylides (formally azomethine ylides) with electron-poor alkenes by conjugate addition followed by cyclization or by [3 + 2] dipolar cycloaddition. The pyrroloquinoline products were formed as single regio- and stereoisomers. These could be converted to other derivatives by Suzuki–Miyaura coupling, reduction or oxidation reactions.
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Affiliation(s)
- Anthony Choi
- Department of Chemistry, University of Sheffield, Brook Hill, Sheffield, S3 7HF, UK
| | - Rebecca M Morley
- Department of Chemistry, University of Sheffield, Brook Hill, Sheffield, S3 7HF, UK
| | - Iain Coldham
- Department of Chemistry, University of Sheffield, Brook Hill, Sheffield, S3 7HF, UK
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12
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Talk RA, El-Tunsi A, Robertson CC, Coldham I. Regioselective Lithiation and Electrophilic Quenching of N
-Boc-3-phenyltetrahydroisoquinoline. European J Org Chem 2019. [DOI: 10.1002/ejoc.201900238] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Ruaa A. Talk
- Department of Chemistry; University of Sheffield; Brook Hill Sheffield S3 7HF UK
| | - Ashraf El-Tunsi
- Department of Chemistry; University of Sheffield; Brook Hill Sheffield S3 7HF UK
| | - Craig C. Robertson
- Department of Chemistry; University of Sheffield; Brook Hill Sheffield S3 7HF UK
| | - Iain Coldham
- Department of Chemistry; University of Sheffield; Brook Hill Sheffield S3 7HF UK
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13
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Alkayar ZTI, Coldham I. Cascade cyclization and intramolecular nitrone dipolar cycloaddition and formal synthesis of 19-hydroxyibogamine. Org Biomol Chem 2019; 17:66-73. [PMID: 30539955 DOI: 10.1039/c8ob02839g] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
A cascade or domino sequence of condensation of hydroxylamine and an aldehyde to give an oxime, cyclization to a nitrone, and intramolecular 1,3-dipolar cycloaddition has been successfully employed where there is branching at C-4 as a route to the iboga alkaloids. Cyclization occurs with displacement of chloride as a leaving group and intramolecular cycloaddition occurs with an alkene as a dipolarophile. The reaction gives an azabicyclo[2.2.2]octane product containing a fused isoxazolidine as a single stereoisomer and this was converted to an isoquinuclidine that completed a formal synthesis of the alkaloid (±)-19-hydroxyibogamine.
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Affiliation(s)
- Ziad T I Alkayar
- Department of Chemistry, University of Sheffield, Sheffield, S3 7HF, UK.
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14
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Affiliation(s)
- Tahani Aeyad
- Department of Chemistry; University of Sheffield; Brook Hill 7HF Sheffield S3 UK
| | - Callum G. Jones
- Department of Chemistry; University of Sheffield; Brook Hill 7HF Sheffield S3 UK
| | - Iain Coldham
- Department of Chemistry; University of Sheffield; Brook Hill 7HF Sheffield S3 UK
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15
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Carter N, Li X, Reavey L, Meijer AJHM, Coldham I. Synthesis and kinetic resolution of substituted tetrahydroquinolines by lithiation then electrophilic quench. Chem Sci 2017; 9:1352-1357. [PMID: 29675183 PMCID: PMC5887238 DOI: 10.1039/c7sc04435f] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Accepted: 12/13/2017] [Indexed: 12/21/2022] Open
Abstract
Treatment of N-Boc-2-aryl-1,2,3,4-tetrahydroquinolines with n-butyllithium in THF at -78 °C resulted in efficient lithiation at the 2-position and the organolithiums were trapped with a variety of electrophiles to give substituted products. Variable temperature NMR spectroscopy gave kinetic data that showed that the rate of tert-butoxycarbonyl (Boc) rotation was fast (ΔG‡ ≈ 45 kJ mol-1 at -78 °C) and in situ ReactIR spectroscopy showed fast lithiation at -78 °C. By carrying out the lithiation in the presence of the chiral ligand sparteine, kinetic resolutions with very high levels of enantioselectivity were achieved. The resulting enantioenriched N-Boc-2-aryltetrahydroquinolines were converted to 2,2-disubstituted products without significant loss in enantiopurity. Most electrophiles add at the 2-position and the chemistry provides a way to access tetrahydroquinolines that are fully substituted alpha to the nitrogen atom. Notably, either enantiomer of the 2,2-disubstituted tetrahydroquinolines can be obtained with high selectivity from the same enantiomer of the chiral ligand. Unusually, when methyl cyanoformate was used as the electrophile, substitution occurred in the ortho position of the aryl ring attached at C-2. This change in regioselectivity on changing the electrophile was probed by deuterium isotope studies and by DFT calculations which suggested that the binding of the cyanoformate altered the structure of the intermediate organolithium. Secondary amine products can be prepared by removing the Boc group with acid or by inducing the Boc group to rearrange to the 2-position in the presence of triethylborane and this carbonyl N-to-C rearrangement occurs with retention of configuration from the intermediate enantiomerically enriched organolithium species.
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Affiliation(s)
- Nicholas Carter
- Department of Chemistry , University of Sheffield , Brook Hill , Sheffield , S3 7HF , UK .
| | - Xiabing Li
- Department of Chemistry , University of Sheffield , Brook Hill , Sheffield , S3 7HF , UK .
| | - Lewis Reavey
- Department of Chemistry , University of Sheffield , Brook Hill , Sheffield , S3 7HF , UK .
| | - Anthony J H M Meijer
- Department of Chemistry , University of Sheffield , Brook Hill , Sheffield , S3 7HF , UK .
| | - Iain Coldham
- Department of Chemistry , University of Sheffield , Brook Hill , Sheffield , S3 7HF , UK .
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16
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Abstract
Preparation of 2,2-disubstituted azepanes was accomplished from N-tert-butoxy(N-Boc)-2-phenylazepane by treatment with butyllithium then electrophilic quench. The lithiation was followed by in situ ReactIR spectroscopy and the rate of rotation of the carbamate was determined by variable temperature (VT)-NMR spectroscopy and by DFT studies. Most electrophiles add α to the nitrogen atom but cyanoformates and chloroformates gave ortho-substituted products. Cyclic carbamates were formed from an aldehyde or ketone electrophile. Kinetic resolution with sparteine was only poorly selective. Removal of the Boc group promoted cyclization to a homoindolizidine or an isoindolinone.
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Affiliation(s)
- Tahani Aeyad
- Department of Chemistry, University of Sheffield
| | | | | | - Iain Coldham
- Department of Chemistry, University of Sheffield
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Affiliation(s)
| | - Darren Collier
- Department of Chemistry, University of Sheffield, Sheffield S3 7HF, U.K
| | - Iain Coldham
- Department of Chemistry, University of Sheffield, Sheffield S3 7HF, U.K
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Sadhukhan A, Hobbs MC, Meijer AJHM, Coldham I. Highly enantioselective metallation-substitution alpha to a chiral nitrile. Chem Sci 2017; 8:1436-1441. [PMID: 28616143 PMCID: PMC5460602 DOI: 10.1039/c6sc03712g] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Accepted: 10/24/2016] [Indexed: 11/21/2022] Open
Abstract
Nitrile anions do not necessarily lack stereochemical integrity and we show good results for stereospecific reaction with a simple magnesium base.
We report the deprotonation of a chiral nitrile and reaction of the resulting chiral organometallic species with a variety of electrophiles to give highly enantiomerically enriched 2-substituted nitrile products. The nitrile was treated with TMPMgCl and the resulting anion, an asymmetric alpha cyano Grignard species, was found to be configurationally stable at low temperature for a short time (half-life several minutes at –104 °C).
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Affiliation(s)
- Arghya Sadhukhan
- Department of Chemistry , University of Sheffield , Brook Hill , Sheffield , S3 7HF , UK .
| | - Melanie C Hobbs
- Department of Chemistry , University of Sheffield , Brook Hill , Sheffield , S3 7HF , UK .
| | - Anthony J H M Meijer
- Department of Chemistry , University of Sheffield , Brook Hill , Sheffield , S3 7HF , UK .
| | - Iain Coldham
- Department of Chemistry , University of Sheffield , Brook Hill , Sheffield , S3 7HF , UK .
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Gotham VJB, Hobbs MC, Burgin R, Turton D, Smythe C, Coldham I. Synthesis and activity of a novel inhibitor of nonsense-mediated mRNA decay. Org Biomol Chem 2016; 14:1559-63. [PMID: 26740124 PMCID: PMC4730866 DOI: 10.1039/c5ob02482j] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
A new route to a tetracyclic lactam was developed and the product, called VG1, was found to inhibit nonsense-mediated mRNA decay at μM concentrations.
During efforts to prepare the known compound NMDI1, a new tetracyclic compound, called VG1, was prepared in six steps. This compound was found to have good activity as an inhibitor of nonsense-mediated mRNA decay.
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Affiliation(s)
- Victoria J B Gotham
- Department of Chemistry, University of Sheffield, Sheffield, S3 7HF, UK. and Department of Biomedical Science, University of Sheffield, Sheffield, S10 2TN, UK
| | - Melanie C Hobbs
- Department of Chemistry, University of Sheffield, Sheffield, S3 7HF, UK.
| | - Ryan Burgin
- Department of Chemistry, University of Sheffield, Sheffield, S3 7HF, UK.
| | - David Turton
- Department of Biomedical Science, University of Sheffield, Sheffield, S10 2TN, UK
| | - Carl Smythe
- Department of Biomedical Science, University of Sheffield, Sheffield, S10 2TN, UK
| | - Iain Coldham
- Department of Chemistry, University of Sheffield, Sheffield, S3 7HF, UK.
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Furnival RC, Saruengkhanphasit R, Holberry HE, Shewring JR, Guerrand HDS, Adams H, Coldham I. Cascade oxime formation, cyclization to a nitrone, and intermolecular dipolar cycloaddition. Org Biomol Chem 2016; 14:10953-10962. [DOI: 10.1039/c6ob01871h] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Abstract
Lithiation then electrophilic quench of tetrahydroisoquinolines provides access to 1-substituted products. Removal of the N-Boc group allows rapid access to natural products such as (±)-crispine A.
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Affiliation(s)
- Ruaa A. Talk
- Department of Chemistry
- University of Sheffield
- Sheffield
- UK
| | | | - Xiabing Li
- Department of Chemistry
- University of Sheffield
- Sheffield
- UK
| | - Iain Coldham
- Department of Chemistry
- University of Sheffield
- Sheffield
- UK
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Coldham I, Alkayar Z, Adams H. Regiochemical and Stereochemical Studies of the Intramolecular Dipolar Cycloaddition of Nitrones Derived from Quaternary Aldehydes. Synlett 2015. [DOI: 10.1055/s-0035-1560906] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Affiliation(s)
- Edward J. Cochrane
- Department
of Chemistry, University of Sheffield, Sheffield S3 7HF, United Kingdom
| | | | - Iain Coldham
- Department
of Chemistry, University of Sheffield, Sheffield S3 7HF, United Kingdom
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Pathak RB, Dobson BC, Ghosh N, Ageel KA, Alshawish MR, Saruengkhanphasit R, Coldham I. Synthesis of the tricyclic core of manzamine A. Org Biomol Chem 2015; 13:3331-40. [DOI: 10.1039/c4ob02582b] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
An approach to the ABC tricyclic ring system of the manzamine alkaloids has been achieved. A key step is the intramolecular dipolar cycloaddition of an azomethine ylide.
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Affiliation(s)
| | | | - Nandita Ghosh
- Department of Chemistry
- University of Sheffield
- Sheffield
- UK
| | | | | | | | - Iain Coldham
- Department of Chemistry
- University of Sheffield
- Sheffield
- UK
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Coldham I. Lithium Compounds in Organic Synthesis: From Fundamentals to Applications RenzoLuisi (Editor) and VitoCapriati (Editor) Wiley-VCH; April 2014 555 pages ISBN: 978-3-527-33343-1 576 pages Hardcover £130 E-book £104.99. Appl Organomet Chem 2014. [DOI: 10.1002/aoc.3189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Li X, Coldham I. Synthesis of 1,1-Disubstituted Tetrahydroisoquinolines by Lithiation and Substitution, with in Situ IR Spectroscopy and Configurational Stability Studies. J Am Chem Soc 2014; 136:5551-4. [DOI: 10.1021/ja500485f] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Xiabing Li
- Department
of Chemistry, University of Sheffield, Brook Hill, Sheffield S3 7HF, U.K
| | - Iain Coldham
- Department
of Chemistry, University of Sheffield, Brook Hill, Sheffield S3 7HF, U.K
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Abstract
An efficient kinetic resolution of 2-arylpiperidines was developed using a chiral base.
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Affiliation(s)
| | | | | | - Iain Coldham
- Department of Chemistry
- University of Sheffield
- Sheffield, UK
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Affiliation(s)
- Dinesh Nath
- Department of Chemistry & Biochemistry, Duquesne University, Pittsburgh, Pennsylvania 15282-1530, United States
| | | | - Iain Coldham
- Department
of Chemistry, University of Sheffield, Sheffield S3 7HF, U.K
| | - Fraser F. Fleming
- Department of Chemistry & Biochemistry, Duquesne University, Pittsburgh, Pennsylvania 15282-1530, United States
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Barker G, Alshawish MR, Skilbeck MC, Coldham I. Remarkable Configurational Stability of Magnesiated Nitriles. Angew Chem Int Ed Engl 2013; 52:7700-3. [DOI: 10.1002/anie.201303442] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Indexed: 11/08/2022]
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Li X, Leonori D, Sheikh NS, Coldham I. Synthesis of 1-Substituted Tetrahydroisoquinolines by Lithiation and Electrophilic Quenching Guided by In Situ IR and NMR Spectroscopy and Application to the Synthesis of Salsolidine, Carnegine and Laudanosine. Chemistry 2013; 19:7724-30. [DOI: 10.1002/chem.201301096] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Indexed: 11/06/2022]
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García-Calvo O, Coya E, Lage S, Coldham I, Sotomayor N, Lete E. Intramolecular Carbolithiation Reactions in the Construction of Medium-Sized Rings. Synthesis of Pyrroloisoquinolines, Benzazepines, and Benzazocines. European J Org Chem 2012. [DOI: 10.1002/ejoc.201200994] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Ince HH, Dedeoglu B, Gul S, Aviyente V, Coldham I. Selectivity in the aggregates of the chiral organolithiumN-Boc-2-lithiopiperidine with a chiral ligand: a DFT study. Mol Phys 2012. [DOI: 10.1080/00268976.2011.647103] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Sheikh NS, Leonori D, Barker G, Firth JD, Campos KR, Meijer AJHM, O'Brien P, Coldham I. An experimental and in situ IR spectroscopic study of the lithiation-substitution of N-Boc-2-phenylpyrrolidine and -piperidine: controlling the formation of quaternary stereocenters. J Am Chem Soc 2012; 134:5300-8. [PMID: 22339321 DOI: 10.1021/ja211398b] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A general and enantioselective synthesis of 2-substituted 2-phenylpyrrolidines and -piperidines, an important class of pharmaceutically relevant compounds that contain a quaternary stereocenter, has been developed. The approach involves lithiation-substitution of enantioenriched N-Boc-2-phenylpyrrolidine or -piperidine (prepared by asymmetric Negishi arylation or catalytic asymmetric reduction, respectively). The combined use of synthetic experiments and in situ IR spectroscopic monitoring allowed optimum lithiation conditions to be identified: n-BuLi in THF at -50 °C for 5-30 min. Monitoring of the lithiation using in situ IR spectroscopy indicated that the rotation of the tert-butoxycarbonyl (Boc) group is slower in a 2-lithiated pyrrolidine than a 2-lithiated piperidine; low yields for the lithiation-substitution of N-Boc-2-phenylpyrrolidine at -78 °C can be ascribed to this slow rotation. For N-Boc-2-phenylpyrrolidine and -piperidine, the barriers to rotation of the Boc group were determined using density functional theory calculations and variable-temperature (1)H NMR spectroscopy. For the pyrrolidine, the half-life (t(1/2)) for rotation of the Boc group was found to be ∼10 h at -78 °C and ∼3.5 min at -50 °C. In contrast, for the piperidine, t(1/2) was determined to be ∼4 s at -78 °C.
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Affiliation(s)
- Nadeem S Sheikh
- Department of Chemistry, University of Sheffield, Brook Hill, Sheffield S3 7HF, UK
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Thompson MJ, Louth JC, Little SM, Jackson MP, Boursereau Y, Chen B, Coldham I. Synthesis and Evaluation of 1-Amino-6-halo-β-carbolines as Antimalarial and Antiprion Agents. ChemMedChem 2012; 7:578-86. [DOI: 10.1002/cmdc.201200002] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2012] [Indexed: 11/06/2022]
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Coldham I, Burrell AJM, Guerrand HDS, Watson L, Martin NG, Oram N. Synthesis of fused tricyclic amines unsubstituted at the ring-junction positions by a cascade condensation, cyclization, cycloaddition then decarbonylation strategy. Beilstein J Org Chem 2012; 8:107-11. [PMID: 22423277 PMCID: PMC3302069 DOI: 10.3762/bjoc.8.11] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2011] [Accepted: 12/23/2011] [Indexed: 11/23/2022] Open
Abstract
Heating aldehydes that contain a protected hydroxymethyl group, a tethered alkyl chloride and a tethered alkenyl group at the α-position of the aldehyde with an amine sets up a cascade (tandem) reaction sequence involving condensation to an intermediate imine, then cyclization and formation of an intermediate azomethine ylide and then intramolecular dipolar cycloaddition. The fused tricyclic products are formed with complete or very high stereochemical control. The hydroxymethyl group was converted into an aldehyde – which could be removed to give the tricyclic amine products that are unsubstituted at the ring junction positions – or was converted into an alkene, which allowed the formation of the core ring system of the alkaloids scandine and meloscine.
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Affiliation(s)
- Iain Coldham
- Department of Chemistry, University of Sheffield, Brook Hill, Sheffield S3 7HF, United Kingdom
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Coldham I, J. M. Burrell A, Watson L, Oram N, G. Martin N. Synthesis of Fused Tricyclic Heterocycles by Condensation, Cyclization, Dipolar Cycloaddition Cascade of α-Benzenesulfonyl and α-Phenylthio Substituted Aldehydes. HETEROCYCLES 2012. [DOI: 10.3987/com-11-s(p)29] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Coldham I, Watson L, Adams H, Martin NG. Synthesis of the Core Ring System of the Yuzurimine-Type Daphniphyllum Alkaloids by Cascade Condensation, Cyclization, Cycloaddition Chemistry. J Org Chem 2011; 76:2360-6. [DOI: 10.1021/jo2000868] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Iain Coldham
- Department of Chemistry, University of Sheffield, Brook Hill, Sheffield S3 7HF, U.K
| | - Luke Watson
- Department of Chemistry, University of Sheffield, Brook Hill, Sheffield S3 7HF, U.K
| | - Harry Adams
- Department of Chemistry, University of Sheffield, Brook Hill, Sheffield S3 7HF, U.K
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Coldham I, Burrell AJM, Guerrand HDS, Oram N. Cascade cyclization, dipolar cycloaddition to bridged tricyclic amines related to the Daphniphyllum alkaloids. Org Lett 2011; 13:1267-9. [PMID: 21314102 DOI: 10.1021/ol102961x] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A tandem one-pot reaction of an aldehyde with a primary amine involving condensation and then cyclization (N-alkylation), followed by intramolecular dipolar cycloaddition of the resulting nitrone or azomethine ylide, provides a synthesis of bridged tricyclic amines. The reaction was most successful using hydroxylamine, and when the dipolarophile was an unsaturated ester, subsequent reduction of the N-O bond and cyclization to the lactam provided the core ring system of the yuzurimine, daphnilactone B, and bukittinggine type Daphniphyllum alkaloids.
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Affiliation(s)
- Iain Coldham
- Department of Chemistry, University of Sheffield, Brook Hill, Sheffield, S3 7HF, UK.
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Guerrand HDS, Adams H, Coldham I. Cascade cyclization, dipolar cycloaddition of azomethine imines for the synthesis of pyrazolidines. Org Biomol Chem 2011; 9:7921-8. [DOI: 10.1039/c1ob06122d] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Franklin AI, Bensa D, Adams H, Coldham I. Transannular dipolar cycloaddition as an approach towards the synthesis of the core ring system of the sarain alkaloids. Org Biomol Chem 2011; 9:1901-7. [DOI: 10.1039/c0ob01019g] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Garcia-Calvo O, Sotomayor N, Lete E, Coldham I. Organolithium or Heck type cyclization of N-ortho-iodobenzyl-2-alkenylpyrrolidines to give indolizidines. ARKIVOC 2010. [DOI: 10.3998/ark.5550190.0012.507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Coldham I, Leonori D. Regioselective and stereoselective copper(I)-promoted allylation and conjugate addition of N-Boc-2-lithiopyrrolidine and N-Boc-2-lithiopiperidine. J Org Chem 2010; 75:4069-77. [PMID: 20469892 DOI: 10.1021/jo100415x] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Copper salts have been screened for transmetalation and electrophilic quench of N-tert-butoxycarbonyl-2-lithiopyrrolidine (N-Boc-2-lithiopyrrolidine) and N-Boc-2-lithiopiperidine, formed by deprotonation of N-Boc-pyrrolidine and N-Boc-piperidine, respectively. Transmetalation with zinc chloride then (lithium chloride solubilized) copper cyanide followed by allylation typically gives mixtures of regioisomers (S(N)2 and S(N)2' products), whereas transmetalation with copper iodide.TMEDA then allylation occurs regioselectively (S(N)2 mechanism). Addition to an enone or alpha,beta-unsaturated ester occurs by 1,4-addition. Asymmetric deprotonation of N-Boc-pyrrolidine or dynamic resolution in the presence of a chiral ligand of N-Boc-2-lithiopiperidine followed by the zinc/copper chemistry was successful and gave the allylated pyrrolidine and piperidine products with good enantioselectivity, although use of the copper iodide chemistry resulted in some loss of enantiopurity. The chemistry provides formal syntheses of (+)-allosedridine, (+)-lasubine II, and (+)-pseudohygroline and has been used for the synthesis of (+)-coniine, (-)-pelletierine, (+)-coniceine, (-)-norhygrine, and the ant extract alkaloids cis- and trans-2-butyl-5-propylpyrrolidine.
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Affiliation(s)
- Iain Coldham
- Department of Chemistry, University of Sheffield, Brook Hill, Sheffield S3 7HF, UK.
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Coldham I, Raimbault S, Whittaker DTE, Chovatia PT, Leonori D, Patel JJ, Sheikh NS. Asymmetric substitutions of 2-lithiated N-boc-piperidine and N-Boc-azepine by dynamic resolution. Chemistry 2010; 16:4082-90. [PMID: 20175161 DOI: 10.1002/chem.200903059] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Proton abstraction of N-tert-butoxycarbonyl-piperidine (N-Boc-piperidine) with sBuLi and TMEDA provides a racemic organolithium that can be resolved using a chiral ligand. The enantiomeric organolithiums can interconvert so that a dynamic resolution occurs. Two mechanisms for promoting enantioselectivity in the products are possible. Slow addition of an electrophile such as trimethylsilyl chloride allows dynamic resolution under kinetic control (DKR). This process occurs with high enantioselectivity and is successful by catalysis with substoichiometric chiral ligand (catalytic dynamic kinetic resolution). Alternatively, the two enantiomers of this organolithium can be resolved under thermodynamic control with good enantioselectivity (dynamic thermodynamic resolution, DTR). The best ligands found are based on chiral diamino-alkoxides. Using DTR, a variety of electrophiles can be used to provide an asymmetric synthesis of enantiomerically enriched 2-substituted piperidines, including (after Boc deprotection) the alkaloid (+)-beta-conhydrine. The chemistry was extended, albeit with lower yields, to the corresponding 2-substituted seven-membered azepine ring derivatives.
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Affiliation(s)
- Iain Coldham
- Department of Chemistry, University of Sheffield, Brook Hill, Sheffield S3 7HF, UK.
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Stead D, Carbone G, O’Brien P, Campos KR, Coldham I, Sanderson A. Asymmetric Deprotonation of N-Boc Piperidine: React IR Monitoring and Mechanistic Aspects. J Am Chem Soc 2010; 132:7260-1. [DOI: 10.1021/ja102043e] [Citation(s) in RCA: 141] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Darren Stead
- Department of Chemistry, University of York, Heslington, York YO10 5DD, U.K., Department of Process Research, Merck Research Laboratories, Rahway, New Jersey 07065, Department of Chemistry, University of Sheffield, Brook Hill, Sheffield, S3 7HF, U.K., and Eli Lilly and Co. Ltd., Lilly Research Centre, Erl Wood Manor, Sunninghill Road, Windlesham, Surrey, GU20 6PH, U.K
| | - Giorgio Carbone
- Department of Chemistry, University of York, Heslington, York YO10 5DD, U.K., Department of Process Research, Merck Research Laboratories, Rahway, New Jersey 07065, Department of Chemistry, University of Sheffield, Brook Hill, Sheffield, S3 7HF, U.K., and Eli Lilly and Co. Ltd., Lilly Research Centre, Erl Wood Manor, Sunninghill Road, Windlesham, Surrey, GU20 6PH, U.K
| | - Peter O’Brien
- Department of Chemistry, University of York, Heslington, York YO10 5DD, U.K., Department of Process Research, Merck Research Laboratories, Rahway, New Jersey 07065, Department of Chemistry, University of Sheffield, Brook Hill, Sheffield, S3 7HF, U.K., and Eli Lilly and Co. Ltd., Lilly Research Centre, Erl Wood Manor, Sunninghill Road, Windlesham, Surrey, GU20 6PH, U.K
| | - Kevin R. Campos
- Department of Chemistry, University of York, Heslington, York YO10 5DD, U.K., Department of Process Research, Merck Research Laboratories, Rahway, New Jersey 07065, Department of Chemistry, University of Sheffield, Brook Hill, Sheffield, S3 7HF, U.K., and Eli Lilly and Co. Ltd., Lilly Research Centre, Erl Wood Manor, Sunninghill Road, Windlesham, Surrey, GU20 6PH, U.K
| | - Iain Coldham
- Department of Chemistry, University of York, Heslington, York YO10 5DD, U.K., Department of Process Research, Merck Research Laboratories, Rahway, New Jersey 07065, Department of Chemistry, University of Sheffield, Brook Hill, Sheffield, S3 7HF, U.K., and Eli Lilly and Co. Ltd., Lilly Research Centre, Erl Wood Manor, Sunninghill Road, Windlesham, Surrey, GU20 6PH, U.K
| | - Adam Sanderson
- Department of Chemistry, University of York, Heslington, York YO10 5DD, U.K., Department of Process Research, Merck Research Laboratories, Rahway, New Jersey 07065, Department of Chemistry, University of Sheffield, Brook Hill, Sheffield, S3 7HF, U.K., and Eli Lilly and Co. Ltd., Lilly Research Centre, Erl Wood Manor, Sunninghill Road, Windlesham, Surrey, GU20 6PH, U.K
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Coldham I, Adams H, Ashweek NJ, Barker TA, Reeder AT, Skilbeck MC. Synthesis of 2-hydroxy-3-indolinones and 3-hydroxy-2-indolinones by anionic cyclization, in situ oxidation and rearrangement. Tetrahedron Lett 2010. [DOI: 10.1016/j.tetlet.2010.02.159] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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