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Tong Z, Smith PJ, Pickford HD, Christensen KE, Anderson EA. Gold-Catalyzed Cyclization of Yndiamides with Isoxazoles via α-Imino Gold Fischer Carbenes. Chemistry 2023; 29:e202302821. [PMID: 37767940 PMCID: PMC10947298 DOI: 10.1002/chem.202302821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 09/27/2023] [Accepted: 09/28/2023] [Indexed: 09/29/2023]
Abstract
Gold catalysis is an important method for alkyne functionalization. Here we report the gold-catalyzed formal [3+2] aminative cyclization of yndiamides and isoxazoles in a direct synthesis of polysubstituted diaminopyrroles, which are important motifs in drug discovery. Key to this process is the formation, and subsequent cyclization, of an α-imino gold Fischer carbene, which represents a new type of gold carbene intermediate. The reaction proceeds rapidly under mild conditions, with high regioselectivity being achieved by introducing a subtle steric bias between the nitrogen substituents on the yndiamide. DFT calculations revealed that the key to this regioselectivity was the interconversion of isomeric gold keteniminiun ions via a low-barrier π-complex transition state, which establishes a Curtin-Hammett scenario for isoxazole addition. By using benzisoxazoles as substrates, the reaction outcome could be switched to a formal [5+2] cyclization, leading to 1,4-oxazepines.
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Affiliation(s)
- Zixuan Tong
- Chemistry Research LaboratoryDepartment of ChemistryUniversity of Oxford12 Mansfield RoadOxfordOX1 3TAUK
| | - Philip J. Smith
- Chemistry Research LaboratoryDepartment of ChemistryUniversity of Oxford12 Mansfield RoadOxfordOX1 3TAUK
| | - Helena D. Pickford
- Chemistry Research LaboratoryDepartment of ChemistryUniversity of Oxford12 Mansfield RoadOxfordOX1 3TAUK
| | - Kirsten E. Christensen
- Chemistry Research LaboratoryDepartment of ChemistryUniversity of Oxford12 Mansfield RoadOxfordOX1 3TAUK
| | - Edward A. Anderson
- Chemistry Research LaboratoryDepartment of ChemistryUniversity of Oxford12 Mansfield RoadOxfordOX1 3TAUK
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2
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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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3
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Körner L, Ho LP, Puchta R, Stanger A, Tamm M. Dimorpholinoacetylene and Its Use for the Synthesis of Tetraaminocyclobutadiene Species. Chemistry 2022; 28:e202202737. [PMID: 36148808 PMCID: PMC9828195 DOI: 10.1002/chem.202202737] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Indexed: 01/12/2023]
Abstract
The new diaminoacetylene (DAA) dimorpholinoacetylene (3) was prepared from 1,1-dimorpholinoethene (1) by bromination to form the dibromoketene aminal 2, which upon lithiation afforded 3 through a Fritsch-Buttenberg-Wiechell rearrangement. Heating 3 at elevated temperatures resulted in a complete conversion into the dimer 1,1,2,4-tetramorpholino-1-buten-3-yne (4), which was used for the synthesis of four-membered cyclic bent allene (CBA) transition-metal complexes of the type [(CBA)MLn ] (5-7; MLn =AuCl, RhCl(COD), RhCl(CO)2 ; CBA=1,3,4,4-tetramorpholino-1,2-cyclobutadiene; COD=1,5-cyclooctadiene). The reaction of 3 with tetraethylammonium bromide gave 1,2,3,4-tetramorpholinocyclobutenylium bromide (8), which reacted with bromine to form 1,2,3,4-tetra(morpholino)cyclobutenediylium bis(tribromide) (9). Compound 9 represents the first fully characterized compound containing a tetraaminocyclobutadiene dication and displays a nearly planar C4 N4 core as shown by X-ray diffraction analysis. Detailed quantum chemical calculations were performed to assess the aromaticity of tetraaminocyclubutadiene dications by employing the Nucleus Independent Chemical Shift (NICS) method and current density analysis.
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Affiliation(s)
- Lukas Körner
- Institut für Anorganische und Analytische ChemieTechnische Universität BraunschweigHagenring 3038106BraunschweigGermany
| | - Luong Phong Ho
- Institut für Anorganische und Analytische ChemieTechnische Universität BraunschweigHagenring 3038106BraunschweigGermany
| | - Ralph Puchta
- Department Chemie und PharmazieFriedrich-Alexander Universität Erlangen-NürnbergEgerlandstr. 191058ErlangenGermany
| | - Amnon Stanger
- Schulich Department of Chemistry, TechnionHaifa32000Israel
| | - Matthias Tamm
- Institut für Anorganische und Analytische ChemieTechnische Universität BraunschweigHagenring 3038106BraunschweigGermany
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Smith PJ, Tong Z, Ragus J, Solon P, Shimkin KW, Anderson EA. Rhodium-Catalyzed [2 + 2 + 2] Cyclotrimerizations of Yndiamides with Alkynes. Org Lett 2022; 24:7522-7526. [PMID: 36214595 DOI: 10.1021/acs.orglett.2c02770] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Yndiamides offer opportunities for the synthesis of vicinally nitrogen-disubstituted aromatics and azacycles. Here we report the Rh-catalyzed cyclotrimerization of alkynyl yndiamides with alkynes, the regiochemical outcome of which is controlled by the electronic properties of the alkyne partner, enabling the formation of 7-aminoindolines with excellent selectivity (up to >20:1 r.r.). We also report a complementary synthesis of bicyclic 1,2-dianiline derivatives by cyclotrimerization of yndiamides with terminal diynes, where slow addition of the diyne overcomes self-dimerization.
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Affiliation(s)
- Philip J Smith
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, 12 Mansfield Road, OxfordOX1 3TA, U.K
| | - Zixuan Tong
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, 12 Mansfield Road, OxfordOX1 3TA, U.K
| | - Julia Ragus
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, 12 Mansfield Road, OxfordOX1 3TA, U.K
| | - Pearse Solon
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, 12 Mansfield Road, OxfordOX1 3TA, U.K
| | - Kirk W Shimkin
- Discovery Chemistry, Therapeutics Discovery, Janssen Research & Development, LLC, Spring House, Pennsylvania19477, United States
| | - Edward A Anderson
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, 12 Mansfield Road, OxfordOX1 3TA, U.K
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5
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Huang S, Ma J, Yi Y, Li M, Cai P, Wu N. Synthesis of orthogonal push-pull chromophores via click reaction of arylynamines. Org Biomol Chem 2022; 20:4081-4085. [PMID: 35521652 DOI: 10.1039/d2ob00677d] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Herein, we report a catalyst-free 'click' reaction: metal-free [2 + 2] cycloaddition-retro-electrocyclisation (CA-RE) of arylynamines with the sluggish acceptor tetracyanoquinodimethane (TCNQ) to provide orthogonal electron-push-pull light-harvesting small molecules: N-heterocyclic dicyanoquinodimethane-substituted methylene malononitriles. Ynamines are reactive alkynes and tend to induce over-reactions with the CA-RE adducts. The reactivity of arylynamines was balanced properly by ensuring the electron-density of the nitrogen atom was delocalised more over the aromatic rings than the triple bond.
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Affiliation(s)
- Shuangping Huang
- College of Biomedical Engineering, Taiyuan University of Technology, Taiyuan, Shanxi, 030024, China
| | - Jing Ma
- College of Biomedical Engineering, Taiyuan University of Technology, Taiyuan, Shanxi, 030024, China
| | - Yikun Yi
- School of Chemical Engineering and Technology, Xi'an Jiaotong University, Xi'an, Shann'xi, 710049, China
| | - Mingtao Li
- School of Chemical Engineering and Technology, Xi'an Jiaotong University, Xi'an, Shann'xi, 710049, China
| | - Ping Cai
- School of Material Science and Engineering & Guangxi Key Laboratory of Information Materials, Guilin University of Electronic Technology, Guilin, Guangxi, 541004, China
| | - Na Wu
- School of Chemistry and Biosciences, Faculty of Life Sciences, University of Bradford, Bradford, West Yorkshire, BD7 1DP, UK.
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Reactant-induced photoactivation of in situ generated organogold intermediates leading to alkynylated indoles via Csp 2-Csp cross-coupling. Nat Commun 2022; 13:2295. [PMID: 35484155 PMCID: PMC9051093 DOI: 10.1038/s41467-022-29982-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Accepted: 04/06/2022] [Indexed: 11/16/2022] Open
Abstract
Photosensitization of organogold intermediates is an emerging field in catalysis. In this context, an access to 2,3-disubstituted indoles from o-alkynyl aniline and iodoalkyne derivatives via a gold-catalyzed sequence under visible-light irradiation and in the absence of an exogenous photocatalyst was uncovered. A wide scope of the process is observed. Of note, 2-iodo-ynamides can be used as electrophiles in this cross-coupling reaction. The resulting N-alkynyl indoles lend themselves to post-functionalization affording valuable scaffolds, notably benzo[a]carbazoles. Mechanistic studies converge on the fact that a potassium sulfonyl amide generates emissive aggregates in the reaction medium. Static quenching of these aggregates by a vinylgold(I) intermediate yields to an excited state of the latter, which can react with an electrophile via oxidative addition and reductive elimination to forge the key C-C bond. This reactant-induced photoactivation of an organogold intermediate opens rich perspectives in the field of cross-coupling reactions. Dual photo- and metal-catalysis is generally not well-understood when the metal catalyst is a gold complex. Here the authors show that a variation of a known metallaphotoredox annulation is possible without an added photocatalyst, proceeding putatively through a gold–intermediate photosensitization by the aggregate of a potassium amide reactant, and yielding indole derivatives.
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Gayyur, Choudhary S, Kant R, Ghosh N. Synergetic copper/zinc catalysis: synthesis of aryl/heteroaryl-fused 1 H-pyrrolo[3,2- c]pyridines. Chem Commun (Camb) 2022; 58:1974-1977. [PMID: 35044384 DOI: 10.1039/d1cc05514c] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Scaffolds having a 1H-pyrrolo[3,2-c]pyridine core show significant biological activity. Herein, we report a synergetic copper/zinc-catalyzed one-step annulation reaction of 2-amino (hetero)arylnitriles with ynamide-derived buta-1,3-diynes to deliver 1H-pyrrolo[3,2-c]quinoline-2,4-diamine derivatives in moderate to good yields. The annulation reaction follows a double cyclization pathway. The gram-scale synthesis of 1H-pyrrolo[3,2-c]quinoline-2,4-diamine proves the practicality of this protocol.
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Affiliation(s)
- Gayyur
- Medicinal & Process Chemistry Division, CSIR-Central Drug Research Institute, Lucknow 226031, India.
| | - Shivani Choudhary
- Medicinal & Process Chemistry Division, CSIR-Central Drug Research Institute, Lucknow 226031, India. .,Academy of Scientific and Innovative Research, Ghaziabad 201002, India
| | - Ruchir Kant
- Molecular and Structural Biology Division, CSIR-Central Drug Research Institute, Lucknow 226031, India
| | - Nayan Ghosh
- Medicinal & Process Chemistry Division, CSIR-Central Drug Research Institute, Lucknow 226031, India. .,Academy of Scientific and Innovative Research, Ghaziabad 201002, India
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9
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Anderson EA, Garry OL, Mansfield SJ. Regio- and Stereoselective Addition of Brønsted Acids to Yndiamides: Synthesis of N,O,N- and N,S,N-Trisubstituted Ketene Acetals. SYNTHESIS-STUTTGART 2021. [DOI: 10.1055/a-1638-5783] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
AbstractYndiamides, N,N-disubstituted alkynes, are versatile building blocks for the synthesis of nitrogen-containing organic molecules. Unlike ynamides, relatives that are inherently polarized by a single nitrogen substituent, their pseudo-symmetric nature renders regioselective reactions challenging. Here we report investigations into the regioselective addition of Brønsted acids to non-symmetric yndiamides, a reaction that delivers N,O,N- and N,S,N-trisubstituted ketene acetals with excellent regio- and stereoselectivity.
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10
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Smith PJ, Jiang Y, Tong Z, Pickford HD, Christensen KE, Nugent J, Anderson EA. Synthesis of Polysubstituted Fused Pyrroles by Gold-Catalyzed Cycloisomerization/1,2-Sulfonyl Migration of Yndiamides. Org Lett 2021; 23:6547-6552. [PMID: 34369785 DOI: 10.1021/acs.orglett.1c02360] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Yndiamides (bis-N-substituted alkynes) are valuable precursors to azacycles. Here we report a cycloisomerization/1,2-sulfonyl migration of alkynyl-yndiamides to form tetrahydropyrrolopyrroles, unprecedented heterocyclic scaffolds that are relevant to medicinal chemistry. This functional group tolerant transformation can be achieved using Au(I) catalysis that proceeds at ambient temperature, and a thermally promoted process. The utility of the products is demonstrated by a range of reactions to functionalize the fused pyrrole core.
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Affiliation(s)
- Philip J Smith
- Chemistry Research Laboratory, 12 Mansfield Road, Oxford OX1 3TA, U.K
| | - Yubo Jiang
- Faculty of Science, Kunming University of Science and Technology, Kunming 650500, China
| | - Zixuan Tong
- Chemistry Research Laboratory, 12 Mansfield Road, Oxford OX1 3TA, U.K
| | - Helena D Pickford
- Chemistry Research Laboratory, 12 Mansfield Road, Oxford OX1 3TA, U.K
| | | | - Jeremy Nugent
- Chemistry Research Laboratory, 12 Mansfield Road, Oxford OX1 3TA, U.K
| | - Edward A Anderson
- Chemistry Research Laboratory, 12 Mansfield Road, Oxford OX1 3TA, U.K
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11
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Tong Z, Garry OL, Smith PJ, Jiang Y, Mansfield SJ, Anderson EA. Au(I)-Catalyzed Oxidative Functionalization of Yndiamides. Org Lett 2021; 23:4888-4892. [DOI: 10.1021/acs.orglett.1c01625] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Zixuan Tong
- Chemistry Research Laboratory, 12 Mansfield Road, Oxford, OX1 3TA, U.K
| | - Olivia L. Garry
- Chemistry Research Laboratory, 12 Mansfield Road, Oxford, OX1 3TA, U.K
| | - Philip J. Smith
- Chemistry Research Laboratory, 12 Mansfield Road, Oxford, OX1 3TA, U.K
| | - Yubo Jiang
- Faculty of Science, Kunming University of Science and Technology, Kunming 650500, China
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12
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Mathur P, Misra S. Metal-carbonyl promoted multicomponent coupling of alkynes for the synthesis of heterocyclic compounds. ADVANCES IN ORGANOMETALLIC CHEMISTRY 2020. [DOI: 10.1016/bs.adomc.2019.09.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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13
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Mansfield SJ, Smith RC, Yong JRJ, Garry OL, Anderson EA. A General Copper-Catalyzed Synthesis of Ynamides from 1,2-Dichloroenamides. Org Lett 2019; 21:2918-2922. [DOI: 10.1021/acs.orglett.9b00971] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
| | - Russell C. Smith
- Janssen PRD, 3210 Merryfield Row, San Diego, California 92121, United States
| | | | - Olivia L. Garry
- Chemistry Research Laboratory, 12 Mansfield Road, Oxford, OX1 3TA, U.K
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14
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15
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Moskowitz M, Wolf C. Catalytic Enantioselective Ynamide Additions to Isatins: Concise Access to Oxindole Alkaloids. Angew Chem Int Ed Engl 2019; 58:3402-3406. [PMID: 30695127 DOI: 10.1002/anie.201814074] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 01/28/2019] [Indexed: 11/05/2022]
Abstract
The highly enantioselective addition of terminal ynamides to a variety of isatins, catalyzed by a bisoxazolidine copper complex under mild, base-free reaction conditions, is described. The reaction is broad in scope, scalable, applicable to unprotected isatins, and provides efficient access to 3-hydroxyoxindoles carrying a tetrasubstituted chiral center with excellent yields and enantioselectivities. Synthetically versatile, multifunctional 3-hydroxyindolinones are obtained by hydration, partial hydrogenation, or hydroxyacyloxylation of the ynamide moiety at room temperature and exhaustive hydrogenation followed by reductive detosylation and spontaneous cyclization affords cinchonamidine alkaloids.
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Affiliation(s)
- Max Moskowitz
- Department of Chemistry, Georgetown University, 37th and O Streets, Washington, DC, 20057, USA
| | - Christian Wolf
- Department of Chemistry, Georgetown University, 37th and O Streets, Washington, DC, 20057, USA
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Moskowitz M, Wolf C. Catalytic Enantioselective Ynamide Additions to Isatins: Concise Access to Oxindole Alkaloids. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201814074] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- Max Moskowitz
- Department of Chemistry; Georgetown University; 37 and O Streets Washington DC 20057 USA
| | - Christian Wolf
- Department of Chemistry; Georgetown University; 37 and O Streets Washington DC 20057 USA
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17
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Novartis Chemistry Lectureship 2018–2019: E. A. Anderson, M. B. Francis, R. Martín, M. Sodeoka. Angew Chem Int Ed Engl 2019; 58:1549. [DOI: 10.1002/anie.201813736] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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18
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Novartis Chemistry Lectureship 2018–2019: E. A. Anderson, M. B. Francis, R. Martín, M. Sodeoka. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201813736] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Marien N, Reddy BN, De Vleeschouwer F, Goderis S, Van Hecke K, Verniest G. Metal-Free Cyclization of ortho
-Nitroaryl Ynamides and Ynamines towards Spiropseudoindoxyls. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201800340] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Niels Marien
- Research Group of Organic Chemistry (ORGC), Department of Chemistry and Department of Bio-engineering Sciences; Faculty of Science and Bio-engineering Sciences; Vrije Universiteit Brussel (VUB); Pleinlaan 2 1050 Brussels Belgium
| | - B. Narendraprasad Reddy
- Research Group of Organic Chemistry (ORGC), Department of Chemistry and Department of Bio-engineering Sciences; Faculty of Science and Bio-engineering Sciences; Vrije Universiteit Brussel (VUB); Pleinlaan 2 1050 Brussels Belgium
| | | | - Steven Goderis
- Research Group of Analytical, Environmental and Geochemistry (AMGC); VUB; Belgium
| | - Kristof Van Hecke
- Department of Chemistry; Ghent University; Krijgslaan 281-S3 9000 Ghent Belgium
| | - Guido Verniest
- Research Group of Organic Chemistry (ORGC), Department of Chemistry and Department of Bio-engineering Sciences; Faculty of Science and Bio-engineering Sciences; Vrije Universiteit Brussel (VUB); Pleinlaan 2 1050 Brussels Belgium
- Janssen Pharmaceutical Companies of Johnson & Johnson, PDMS-AD; Turnhoutseweg 30 2340 Beerse Belgium
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20
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Marien N, Reddy BN, De Vleeschouwer F, Goderis S, Van Hecke K, Verniest G. Metal-Free Cyclization of ortho-Nitroaryl Ynamides and Ynamines towards Spiropseudoindoxyls. Angew Chem Int Ed Engl 2018; 57:5660-5664. [PMID: 29570239 DOI: 10.1002/anie.201800340] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 02/21/2018] [Indexed: 11/11/2022]
Abstract
An efficient metal-free cascade reaction between 1-dibromovinyl-2-nitro-substituted arenes and secondary amines results in the formation of polycyclic pseudoindoxyls in a single step. The reaction mechanism leading to these fused ring systems was investigated, and is believed to involve the initial formation of nitroarylated ynamines/ynamides. These intermediates cycloisomerize towards N-alkenyl-tethered 2-aminoisatogens via a carbene intermediate as demonstrated by QTAIM (quantum theory of atoms in molecules) and ELF (electron localization function) analysis. A subsequent intramolecular dipolar cycloaddition afforded the title compounds.
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Affiliation(s)
- Niels Marien
- Research Group of Organic Chemistry (ORGC), Department of Chemistry and Department of Bio-engineering Sciences, Faculty of Science and Bio-engineering Sciences, Vrije Universiteit Brussel (VUB), Pleinlaan 2, 1050, Brussels, Belgium
| | - B Narendraprasad Reddy
- Research Group of Organic Chemistry (ORGC), Department of Chemistry and Department of Bio-engineering Sciences, Faculty of Science and Bio-engineering Sciences, Vrije Universiteit Brussel (VUB), Pleinlaan 2, 1050, Brussels, Belgium
| | | | - Steven Goderis
- Research Group of Analytical, Environmental and Geochemistry (AMGC), VUB, Belgium
| | - Kristof Van Hecke
- Department of Chemistry, Ghent University, Krijgslaan 281-S3, 9000, Ghent, Belgium
| | - Guido Verniest
- Research Group of Organic Chemistry (ORGC), Department of Chemistry and Department of Bio-engineering Sciences, Faculty of Science and Bio-engineering Sciences, Vrije Universiteit Brussel (VUB), Pleinlaan 2, 1050, Brussels, Belgium.,Janssen Pharmaceutical Companies of Johnson & Johnson, PDMS-AD, Turnhoutseweg 30, 2340, Beerse, Belgium
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