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Li L, Turnbull WL, McDonald R, West FG. Lithium Hydroxide Assisted
Endo
‐Selective [4+4]‐Photocycloaddition of Pyran‐2‐ones. European J Org Chem 2021. [DOI: 10.1002/ejoc.202100122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Lei Li
- Department of Chemistry University of Alberta E3-43 Gunning-Lemieux Chemistry Centre Edmonton AB T6G 2G2 Canada
| | - William L. Turnbull
- Department of Chemistry University of Alberta E3-43 Gunning-Lemieux Chemistry Centre Edmonton AB T6G 2G2 Canada
| | - Robert McDonald
- X-Ray Crystallography Laboratory Department of Chemistry University of Alberta E3-43 Gunning-Lemieux Chemistry Centre Edmonton AB T6G 2G2 Canada
| | - F. G. West
- Department of Chemistry University of Alberta E3-43 Gunning-Lemieux Chemistry Centre Edmonton AB T6G 2G2 Canada
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2
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Guyon H, Boussonnière A, Castanet AS. Readily Accessible 1,2-Amino Ether Ligands for Enantioselective Intramolecular Carbolithiation. J Org Chem 2017; 82:4949-4957. [PMID: 28394126 DOI: 10.1021/acs.joc.7b00423] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A new class of chiral 1,2-amino ether ligands, readily accessible from naturally occurring α-amino- or α-hydroxy acids, was found to provide high levels of both conversion and stereocontrol (up to 95:5 er) in intramolecular carbolithiation reactions, outperforming the benchmark ligand (-)-sparteine. The ligand could be used in a substoichiometric amount (0.25 equiv) without significant loss of enantioselectivity.
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Affiliation(s)
- Hélène Guyon
- Université du Maine and CNRS UMR 6283, Institut des Molécules et Matériaux du Mans , Faculté des Sciences et Techniques, avenue Olivier Messiaen, 72085 Le Mans Cedex 9, France
| | - Anne Boussonnière
- Université du Maine and CNRS UMR 6283, Institut des Molécules et Matériaux du Mans , Faculté des Sciences et Techniques, avenue Olivier Messiaen, 72085 Le Mans Cedex 9, France
| | - Anne-Sophie Castanet
- Université du Maine and CNRS UMR 6283, Institut des Molécules et Matériaux du Mans , Faculté des Sciences et Techniques, avenue Olivier Messiaen, 72085 Le Mans Cedex 9, France
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Burke SJ, Malachowski WP, Mehta SK, Appenteng R. The enantioselective construction of tetracyclic diterpene skeletons with Friedel-Crafts alkylation and palladium-catalyzed cycloalkenylation reactions. Org Biomol Chem 2015; 13:2726-44. [PMID: 25598198 DOI: 10.1039/c4ob02489c] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Due to the profound extent to which natural products inspire medicinal chemists in drug discovery, there is demand for innovative syntheses of these often complex materials. This article describes the synthesis of tricarbocyclic natural product architectures through an extension of the enantioselective Birch-Cope sequence with intramolecular Friedel-Crafts alkylation reactions. Additionally, palladium-catalyzed enol silane cycloalkenylation of the tricarbocyclic structures afforded the challenging bicyclo[3.2.1]octane C/D ring system found in the gibberellins and the ent-kauranes, two natural products with diverse medicinal value. In the case of the ent-kaurane derivative, an unprecedented alkene rearrangement converted four alkene isomers to one final product.
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Affiliation(s)
- Sarah J Burke
- Department of Chemistry, Bryn Mawr College, Bryn Mawr, Pennsylvania 19010-2899, USA.
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Honrado M, Otero A, Fernández-Baeza J, Sánchez-Barba LF, Garcés A, Lara-Sánchez A, Rodríguez AM. Enantiopure N,N,O-scorpionate zinc amide and chloride complexes as efficient initiators for the heteroselective ROP of cyclic esters. Dalton Trans 2014; 43:17090-100. [DOI: 10.1039/c4dt02178a] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Amide-containing zinc heteroscorpionates can act as single-component initiators for the well-controlled ROP of rac-LA to produce heterotactic-enriched materials.
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Affiliation(s)
- Manuel Honrado
- Departamento de Química Inorgánica
- Orgánica y Bioquímica-Centro de Innovación en Química Avanzada (ORFEO-CINQA)
- Universidad de Castilla-La Mancha
- 13071-Ciudad Real, Spain
| | - Antonio Otero
- Departamento de Química Inorgánica
- Orgánica y Bioquímica-Centro de Innovación en Química Avanzada (ORFEO-CINQA)
- Universidad de Castilla-La Mancha
- 13071-Ciudad Real, Spain
| | - Juan Fernández-Baeza
- Departamento de Química Inorgánica
- Orgánica y Bioquímica-Centro de Innovación en Química Avanzada (ORFEO-CINQA)
- Universidad de Castilla-La Mancha
- 13071-Ciudad Real, Spain
| | | | - Andrés Garcés
- Departamento de Ciencias
- Universidad Rey Juan Carlos
- Móstoles-28933-Madrid, Spain
| | - Agustín Lara-Sánchez
- Departamento de Química Inorgánica
- Orgánica y Bioquímica-Centro de Innovación en Química Avanzada (ORFEO-CINQA)
- Universidad de Castilla-La Mancha
- 13071-Ciudad Real, Spain
| | - Ana M. Rodríguez
- Departamento de Química Inorgánica
- Orgánica y Bioquímica-Centro de Innovación en Química Avanzada (ORFEO-CINQA)
- Universidad de Castilla-La Mancha
- 13071-Ciudad Real, Spain
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Vincent MA, Campbell Smith A, Donnard M, Harford PJ, Haywood J, Hillier IH, Clayden J, Wheatley AEH. Lithiated Tertiary Carbanions Display Variable Coordination Modes: Evidence from DFT and NMR Studies. Chemistry 2012; 18:11036-45. [DOI: 10.1002/chem.201200734] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Revised: 04/30/2012] [Indexed: 11/10/2022]
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M. Hodgson D, A. H. Stent M, S. Paton R, X. Wilson F. Unusual Base-Induced Rearrangement of exo-9-Oxabicyclo[4.2.1]non-7-ene Oxide to exo-8-Hydroxybicyclo[3.3.0]octan-2-one. HETEROCYCLES 2012. [DOI: 10.3987/com-11-s(p)35] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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7
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Hayes CJ, Simpkins NS, Kirk DT, Mitchell L, Baudoux J, Blake AJ, Wilson C. Bridgehead Lithiation-Substitution of Bridged Ketones, Lactones, Lactams, and Imides: Experimental Observations and Computational Insights. J Am Chem Soc 2009; 131:8196-210. [DOI: 10.1021/ja9009875] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Christopher J. Hayes
- School of Chemistry, The University of Nottingham, University Park, Nottingham, NG7 2RD United Kingdom
| | - Nigel S. Simpkins
- School of Chemistry, The University of Nottingham, University Park, Nottingham, NG7 2RD United Kingdom
| | - Douglas T. Kirk
- School of Chemistry, The University of Nottingham, University Park, Nottingham, NG7 2RD United Kingdom
| | - Lee Mitchell
- School of Chemistry, The University of Nottingham, University Park, Nottingham, NG7 2RD United Kingdom
| | - Jerome Baudoux
- School of Chemistry, The University of Nottingham, University Park, Nottingham, NG7 2RD United Kingdom
| | - Alexander J. Blake
- School of Chemistry, The University of Nottingham, University Park, Nottingham, NG7 2RD United Kingdom
| | - Claire Wilson
- School of Chemistry, The University of Nottingham, University Park, Nottingham, NG7 2RD United Kingdom
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Koch C, Görls H, Westerhausen M. 8-Amidoquinoline, 8-(Trialkylsilylamido)quinoline, 2-Pyridylmethylamide, and (2-Pyridylmethyl)(trialkylsilyl)amide Complexes of Gallium. Z Anorg Allg Chem 2008. [DOI: 10.1002/zaac.200800088] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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9
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Wrackmeyer B, Klimkina EV, Milius W. Interannular Nitrogen-Lithium Bridges in Ferrocenophanes. Z Anorg Allg Chem 2008. [DOI: 10.1002/zaac.200700398] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Green JR, Majewski M, Snieckus V. Deprotonation of β,β-disubstituted α,β-unsaturated amides - Mechanism and stereochemical consequences. CAN J CHEM 2006. [DOI: 10.1139/v06-112] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A detailed study of the lithium dialkylamide induced deprotonation of β,β-disubstituted α,β-unsaturated amides is presented. The preferential γ-Z-deprotonation and stereochemical outcome of substituents on the γ-Z carbon atom are rationalized in terms of a cyclic eight-membered transition state, which is supported by DFT calculations. Analogous deprotonations on cyclohexylidenecarboxamides reveal a delicate balance of the preference for the eight-membered cyclic transition state with the effects of existing substituents on the ring and the intervention of a twist-boat transition state.Key words: dienolate, amide, deprotonation mechanism, transition state, enolization, regioselectivity, stereoselectivity.
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Shaw D, Best J, Dinnell K, Nadin A, Shearman M, Pattison C, Peachey J, Reilly M, Williams B, Wrigley J, Harrison T. 3,4-Fused cyclohexyl sulfones as γ-secretase inhibitors. Bioorg Med Chem Lett 2006; 16:3073-7. [PMID: 16617016 DOI: 10.1016/j.bmcl.2005.12.083] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2005] [Revised: 12/23/2005] [Accepted: 12/28/2005] [Indexed: 11/16/2022]
Abstract
The 3,4-fused sulfamides, sulfonamides and sulfone have been identified as highly potent gamma-secretase inhibitors. Evaluation of the SAR of substitution within these series has allowed the identification of a range of compounds which significantly reduce brain A beta in transgenic mouse models and thus have potential as possible treatments for Alzheimer's disease.
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Affiliation(s)
- Duncan Shaw
- Department of Medicinal Chemistry, Neuroscience Research Centre, Terlings Park, Eastwick Road, Harlow, Essex CM20 2QR, UK.
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