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Liang G, Anderson EA. Sequencing palladium-catalyzed cycloisomerization cascades in a synthesis of the gelsemine core. Chem Sci 2023; 14:6970-6974. [PMID: 37389268 PMCID: PMC10306092 DOI: 10.1039/d3sc01353g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Accepted: 06/05/2023] [Indexed: 07/01/2023] Open
Abstract
Transition metal-catalyzed cycloisomerization is a powerful strategy for the construction of cyclic organic molecules, and the use of palladium catalysts can deliver a wide range of monocyclic and bicyclic products. However, applications of cycloisomerizations in complex target synthesis in which more than one cycloisomerization process is deployed in a cascade context are rare. Here we report investigations of the relative rates of two different types of ene-ynamide cycloisomerization that form fused and spirocyclic rings, and use of these results to design a sequence-controlled cascade cycloisomerization that prepares the tetracyclic core of gelsemine in a single step. Crucial to this work was an evaluation of the kinetics of each cycloisomerization in competition experiments, which revealed a key influence of the ynamide electron-withdrawing group on the cycloisomerization reaction.
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Affiliation(s)
- Guoduan Liang
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford 12 Mansfield Road Oxford OX1 3TA UK
| | - Edward A Anderson
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford 12 Mansfield Road Oxford OX1 3TA UK
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2
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Design, Synthesis and Evaluation of Fused Bicyclo[2.2.2]octene as a Potential Core Scaffold for the Non-Covalent Inhibitors of SARS-CoV-2 3CLpro Main Protease. Pharmaceuticals (Basel) 2022; 15:ph15050539. [PMID: 35631364 PMCID: PMC9145702 DOI: 10.3390/ph15050539] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 04/22/2022] [Accepted: 04/24/2022] [Indexed: 12/22/2022] Open
Abstract
The emergence of SARS-CoV-2, responsible for the global COVID-19 pandemic, requires the rapid development of novel antiviral drugs that would contribute to an effective treatment alongside vaccines. Drug repurposing and development of new molecules targeting numerous viral targets have already led to promising drug candidates. To this end, versatile molecular scaffolds with high functionalization capabilities play a key role. Starting with the clinically used conformationally flexible HIV-1 protease inhibitors that inhibit replication of SARS-CoV-2 and bind major protease 3CLpro, we designed and synthesized a series of rigid bicyclo[2.2.2]octenes fused to N-substituted succinimides to test whether this core scaffold could support the development of non-covalent 3CLpro inhibitors. Inhibition assays confirmed that some compounds can inhibit the SARS-CoV-2 main protease; the most promising compound 11a inhibited 3CLpro in micromolar range (IC50 = 102.2 μM). Molecular simulations of the target-ligand complex in conjunction with dynophore analyses and endpoint free energy calculations provide additional insight and first recommendations for future optimization. The fused bicyclo[2.2.2]octenes can be used as a new potential starting point in the development of non-covalent SARS-CoV-2 3CLpro protease inhibitors and the study also substantiates the potential of this versatile scaffold for the development of biologically active molecules.
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Weber AK, Schachtner J, Fichtler R, Leermann TM, Neudörfl JM, Jacobi von Wangelin A. Modular synthesis of cyclic cis- and trans-1,2-diamine derivatives. Org Biomol Chem 2015; 12:5267-77. [PMID: 24924419 DOI: 10.1039/c4ob00913d] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Structurally diverse carbocycles with two vicinal nitrogen-substituents were prepared in expedient three-component reactions from simple amines, aldehydes, and nitroalkenes. trans,trans-6-Nitrocyclohex-2-enyl amines were obtained in a one-pot domino reaction involving condensation, tautomerisation, conjugate addition, and nitro-Mannich cyclisation. Upon employment of less nucleophilic carboxamides, a concerted Diels-Alder cycloaddition mechanism operated to give the corresponding cis,trans-nitrocyclohexenyl amides. Both types of substituted carbocycles offer ample opportunities for chemical manipulations at the core and periphery. Ring oxidation with MnO2 affords substituted nitroarenes. Reduction with Zn/HCl provides access to various trans- and cis-diaminocyclohexenes, respectively, in a straight-forward manner. With enantiopure secondary amines, a two-step synthesis of chiral nitrocyclohexadienes was developed (82-94% ee).
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Affiliation(s)
- Anna K Weber
- Department of Chemistry, University of Cologne, Germany
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4
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Noland WE, Kroll NJ, Huisenga MP, Yue RA, Lang SB, Klein ND, Tritch KJ. Crystal structure of (1S,2R,6R,7R,8S,12S)-4,10,17-triphenyl-15-thia-4,10-diaza-penta-cyclo[5.5.5.0(1,16).0(2,6).0(8,12)]hepta-deca-13,16-diene-3,5,9,11-tetrone p-xylene hemisolvate. Acta Crystallogr Sect E Struct Rep Online 2014; 70:550-4. [PMID: 25552990 PMCID: PMC4257460 DOI: 10.1107/s1600536814025094] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Accepted: 11/16/2014] [Indexed: 11/23/2022]
Abstract
A novel meso bicyclo[2.2.2]octene-based compound was obtained from an attempted Diels–Alder reaction. It crystallizes from p-xylene as a hemisolvate. The title tetrone compound, C32H22N2O4S· 0.5C8H10, is the major product (50% yield) of an attempted Diels–Alder reaction of 2-(α-styryl)thiophene with N-phenylmaleimide (2 equivalents) in toluene. Recrystallization of the resulting powder from p-xylene gave the title hemisolvate; the p-xylene molecule is located about an inversion center. In the crystal, the primary tetrone contacts are between a carbonyl O atom and the four flagpole H atoms of the bicyclo[2.2.2]octene core, forming chains along [001].
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Affiliation(s)
- Wayland E Noland
- Department of Chemistry, University of Minnesota, Minneapolis, MN 55455-0431, USA
| | - Neil J Kroll
- Department of Chemistry, University of Minnesota, Minneapolis, MN 55455-0431, USA
| | - Matthew P Huisenga
- Department of Chemistry, University of Minnesota, Minneapolis, MN 55455-0431, USA
| | - Ruixian A Yue
- Department of Chemistry, University of Minnesota, Minneapolis, MN 55455-0431, USA
| | - Simon B Lang
- Department of Chemistry, University of Minnesota, Minneapolis, MN 55455-0431, USA
| | - Nathan D Klein
- Department of Chemistry, University of Minnesota, Minneapolis, MN 55455-0431, USA
| | - Kenneth J Tritch
- Department of Chemistry, University of Minnesota, Minneapolis, MN 55455-0431, USA
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5
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Fang X, Jackstell R, Beller M. Sequential hydroformylation/diels-alder processes: one-pot synthesis of polysubstituted cyclohexenes, cyclohexadienes, and phthalates from alkynes. Chemistry 2014; 20:7939-42. [PMID: 24888893 DOI: 10.1002/chem.201402981] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Indexed: 11/09/2022]
Abstract
A novel, one-pot hydroformylation/Diels-Alder sequence for the synthesis of multisubstituted cyclohexenes, cyclohexadienes, and phthalates has been developed. Various alkynes were efficiently converted into the corresponding products in good yields and with excellent diastereoselectivity through palladium-catalyzed hydroformylation followed by an AAD-type reaction (AAD: Amides-Aldehydes-Dienophiles). In view of the availability of the substrates, the atom-efficiency of the overall process, and the convenient introduction of substituents in the cyclohexene ring, this method complements current methods for the preparation of polysubstituted cyclohexane derivatives.
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Affiliation(s)
- Xianjie Fang
- Leibniz-Institut für Katalyse e.V. an der Universität Rostock, Albert-Einstein-Str. 29 a, 18059 Rostock (Germany)
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Fichtler R, Neudörfl JM, Jacobi von Wangelin A. Practical three-component synthesis of crowded arenes with donor–acceptor substitution. Org Biomol Chem 2011; 9:7224-36. [DOI: 10.1039/c1ob05984j] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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8
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Deagostino A, Prandi C, Toppino A, Venturello P. Palladium-catalysed Heck reaction on 1,2-dien-1-ols: a stereoselective synthesis of α-arylated α,β-unsaturated aldehydes. Tetrahedron 2008. [DOI: 10.1016/j.tet.2008.08.081] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Neumann H, Sergeev A, Beller M. Palladium Catalysts for the Formylation of Vinyl Triflates To Form α,β-Unsaturated Aldehydes. Angew Chem Int Ed Engl 2008; 47:4887-91. [DOI: 10.1002/anie.200800994] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Neumann H, Sergeev A, Beller M. Palladium Catalysts for the Formylation of Vinyl Triflates To Form α,β-Unsaturated Aldehydes. Angew Chem Int Ed Engl 2008. [DOI: 10.1002/ange.200800994] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Hübner S, Jiao H, Michalik D, Neumann H, Klaus S, Strübing D, Spannenberg A, Beller M. In Situ Generation of ChiralN-Dienyl Lactams in a Multicomponent Reaction: An Efficient and Highly Selective Way to Asymmetric Amidocyclohexenes. Chem Asian J 2007; 2:720-33. [PMID: 17458916 DOI: 10.1002/asia.200600428] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Chiral N-dienyl lactams are crucial building blocks for the synthesis of complex organic compounds. However, their generation is rather challenging. This paper reports on a highly efficient and diastereoselective multicomponent methodology utilizing chiral amides, aldehydes, and dienophiles (AAD reaction). The three components readily react under in situ generation of chiral N-dienyl lactams which undergo a subsequent Diels-Alder reaction. Different chiral amides have been employed in the standard protocol delivering yields up to 94%, and selectivities up to 90% de. Moreover, DFT calculations were performed to explain the obtained selectivities.
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Affiliation(s)
- Sandra Hübner
- Leibniz-Institut für Katalyse e.V. an der Universität Rostock, Rostock, Germany
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12
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Hübner S, Michalik D, Jiao H, Neumann H, Klaus S, Strübing D, Spannenberg A, Beller M. Three-Component Reactions with (S)-Methyl Pyroglutamate: An Efficient Way to Diversely Substituted Asymmetric Amidocyclohexenes. Chem Asian J 2007; 2:734-46. [PMID: 17492706 DOI: 10.1002/asia.200700031] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Chiral N-dienyl lactams are crucial building blocks for the synthesis of complex organic compounds. However, their generation is rather challenging. This paper reports the novel one-pot reaction of (S)-methyl pyroglutamate as the amide component with different aldehydes and dienophiles (AAD reaction) to give novel chiral 1-amido-2-cyclohexenes. The corresponding N-dienyl lactams generated in situ undergo subsequent Diels-Alder reactions in good yield and diastereoselectivity. The scope and limitations of the three-component protocol were investigated. X-ray and NMR spectroscopic analysis of the products as well as DFT calculations of the intermediates were also performed to explain the observed stereoselectivity and structural features.
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Affiliation(s)
- Sandra Hübner
- Leibniz-Institut für Katalyse e.V. an der Universität Rostock, 18059 Rostock, Germany
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Strübing D, Neumann H, Jacobi von Wangelin A, Klaus S, Hübner S, Beller M. An easy and general protocol for multicomponent coupling reactions of aldehydes, amides, and dienophiles. Tetrahedron 2006. [DOI: 10.1016/j.tet.2006.08.062] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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14
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Neumann H, Strübing D, Lalk M, Klaus S, Hübner S, Spannenberg A, Lindequist U, Beller M. Synthesis and antimicrobial activity of N-analogous corollosporines. Org Biomol Chem 2006; 4:1365-75. [PMID: 16557326 DOI: 10.1039/b517101f] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Corollosporine is an antimicrobial metabolite, which was isolated from the marine fungus Corollospora maritima. Owing to its basic 4-hydroxyphthalic acid anhydride structure, it has become an attractive target for a structure/activity relationship modelling of derived compounds with potential antibiotic activity. In this regard we report on the straightforward synthesis of hetero analogous corollosporines, which were easily prepared by a three-step reaction sequence, taking advantage of a novel multicomponent reaction (AAD-reaction) and a subsequent aromatization/Grignard reaction protocol. Furthermore, the obtained products were tested in several biological assays to evaluate their antimicrobial activity.
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Affiliation(s)
- Helfried Neumann
- Leibniz-Institut für Katalyse e.V. an der Universität Rostock, Albert-Einstein-Strasse 29a, 18059 Rostock, Germany
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Strübing D, Neumann H, Hübner S, Klaus S, Beller M. Straightforward synthesis of di-, tri- and tetracyclic lactams via catalytic Pauson–Khand and Alder–Ene reactions of MCR products. Tetrahedron 2005. [DOI: 10.1016/j.tet.2005.09.098] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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16
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Strübing D, Neumann H, Hübner S, Klaus S, Beller M. A Novel MCR of Isocyanates, Aldehydes, and Dienophiles. Org Lett 2005; 7:4321-4. [PMID: 16178523 DOI: 10.1021/ol051343a] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
[reaction: see text] A novel one-pot procedure for the three-component coupling reaction of isocyanates, aldehydes, and dienophiles (IAD reaction) has been developed. Condensation of isocyanates and aldehydes and subsequent Diels-Alder reactions with electron-deficient dienophiles furnishes endo-selective amino-substituted cyclohexenes in good yield.
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Affiliation(s)
- Dirk Strübing
- Leibniz-Institut für Organische Katalyse an der Universität Rostock e.V., Albert-Einstein-Strasse 29a, 18059 Rostock, Germany
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Strübing D, Kirschner A, Neumann H, Hübner S, Klaus S, Bornscheuer UT, Beller M. Synthesis of Enantiomerically Pure Cyclohex-2-en-1-ols: Development of Novel Multicomponent Reactions. Chemistry 2005; 11:4210-8. [PMID: 15861377 DOI: 10.1002/chem.200401258] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Multicomponent reactions of aldehydes, dienophiles, and alcohols or carboxylic acid anhydrides have been developed for the first time. In situ generation of 1-acyloxy- and 1-alkoxy-1,3-butadiene derivatives in toluene in the presence of electron-deficient dienophiles provides selective and efficient access to functionalized cyclohex-2-ene-1-ols in good yields. Subsequent enzyme-catalyzed kinetic resolution gave the corresponding enantiomers with high enantioselectivity.
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Affiliation(s)
- Dirk Strübing
- Leibniz-Institut für Organische Katalyse an der Universität Rostock e.V. Buchbinderstr. 5-6, Germany
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