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Furugoori M, Yoshida K, Hashimoto Y, Morita N, Tanaka Iii K, Tamura O. Electrophilic Epoxidation of α,β-Unsaturated Oximes with Dioxiranes and Ring Opening of the Epoxides. Chem Pharm Bull (Tokyo) 2021; 69:1010-1016. [PMID: 34305073 DOI: 10.1248/cpb.c21-00533] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
α,β-Unsaturated oximes underwent electrophilic epoxidation with in-situ-generated dimethyldioxirane to give the corresponding epoxides in good yields. This reaction is an example of "carbonyl umpolung" by transformation of α,β-unsaturated ketones to their oximes. Nucleophilic ring-opening reactions of the epoxides afforded α-substituted products. Shi asymmetric epoxidation of the oximes proceeded with moderate enantioselectivity.
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2
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Ye C, Jiao Y, Chiou MF, Li Y, Bao H. Direct synthesis of pentasubstituted pyrroles and hexasubstituted pyrrolines from propargyl sulfonylamides and allenamides. Chem Sci 2021; 12:9162-9167. [PMID: 34276946 PMCID: PMC8261710 DOI: 10.1039/d1sc02090k] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 06/05/2021] [Indexed: 11/21/2022] Open
Abstract
Multisubstituted pyrroles are important fragments that appear in many bioactive small molecule scaffolds. Efficient synthesis of multisubstituted pyrroles with different substituents from easily accessible starting materials is challenging. Herein, we describe a metal-free method for the preparation of pentasubstituted pyrroles and hexasubstituted pyrrolines with different substituents and a free amino group by a base-promoted cascade addition-cyclization of propargylamides or allenamides with trimethylsilyl cyanide. This method would complement previous methods and support expansion of the toolbox for the synthesis of valuable, but previously inaccessible, highly substituted pyrroles and pyrrolines. Mechanistic studies to elucidate the reaction pathway have been conducted.
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Affiliation(s)
- Changqing Ye
- Key Laboratory of Coal to Ethylene Glycol and Its Related Technology, State Key Laboratory of Structural Chemistry, Center for Excellence in Molecular Synthesis, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences 155 Yangqiao Road West Fuzhou Fujian 350002 People's Republic of China
| | - Yihang Jiao
- Key Laboratory of Coal to Ethylene Glycol and Its Related Technology, State Key Laboratory of Structural Chemistry, Center for Excellence in Molecular Synthesis, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences 155 Yangqiao Road West Fuzhou Fujian 350002 People's Republic of China
| | - Mong-Feng Chiou
- Key Laboratory of Coal to Ethylene Glycol and Its Related Technology, State Key Laboratory of Structural Chemistry, Center for Excellence in Molecular Synthesis, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences 155 Yangqiao Road West Fuzhou Fujian 350002 People's Republic of China
| | - Yajun Li
- Key Laboratory of Coal to Ethylene Glycol and Its Related Technology, State Key Laboratory of Structural Chemistry, Center for Excellence in Molecular Synthesis, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences 155 Yangqiao Road West Fuzhou Fujian 350002 People's Republic of China
| | - Hongli Bao
- Key Laboratory of Coal to Ethylene Glycol and Its Related Technology, State Key Laboratory of Structural Chemistry, Center for Excellence in Molecular Synthesis, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences 155 Yangqiao Road West Fuzhou Fujian 350002 People's Republic of China
- University of Chinese Academy of Sciences Beijing 100049 People's Republic of China
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3
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Longo LS, Siqueira FA, Anjos NS, Santos GFD. Scandium(III)‐Triflate‐Catalyzed Multicomponent Reactions for the Synthesis of Nitrogen Heterocycles. ChemistrySelect 2021. [DOI: 10.1002/slct.202101032] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Luiz S. Longo
- Department of Pharmaceutical Sciences Federal University of São Paulo - UNIFESP Rua São Nicolau 210 09913-030 Diadema SP Brazil
| | - Fernanda A. Siqueira
- Department of Chemistry Federal University of São Paulo - UNIFESP Rua Prof. Arthur Riedel 275 09972-270 Diadema SP Brazil
| | - Nicolas S. Anjos
- Department of Pharmaceutical Sciences Federal University of São Paulo - UNIFESP Rua São Nicolau 210 09913-030 Diadema SP Brazil
| | - Gabriela F. D. Santos
- Department of Pharmaceutical Sciences Federal University of São Paulo - UNIFESP Rua São Nicolau 210 09913-030 Diadema SP Brazil
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Milcendeau P, Zhang Z, Glinsky-Olivier N, van Elslande E, Guinchard X. Au(I)-Catalyzed Pictet-Spengler Reactions All around the Indole Ring. J Org Chem 2021; 86:6406-6422. [PMID: 33887914 DOI: 10.1021/acs.joc.1c00270] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Au(I) complexes catalyze iso-Pictet-Spengler reactions. Ethylamine or methylamine chains were introduced at C2, C4, or the nitrogen atom of the indole ring, and the corresponding substrates were reacted in the presence of aldehydes and catalytic amounts of Au(I) complexes, leading to a variety of polycyclic scaffolds. Selectivity could be achieved in the course of a double iso-Pictet-Spengler reaction involving two successive aldehydes, leading to highly complex molecules.
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Affiliation(s)
- Pierre Milcendeau
- Université Paris-Saclay, CNRS, Institut de Chimie des Substances Naturelles, UPR 2301, 91198 Gif-sur-Yvette, France
| | - Zhenhao Zhang
- Université Paris-Saclay, CNRS, Institut de Chimie des Substances Naturelles, UPR 2301, 91198 Gif-sur-Yvette, France.,LCM, CNRS, Ecole Polytechnique, Institut Polytechnique de Paris, 91128 Palaiseau, France
| | - Nicolas Glinsky-Olivier
- Université Paris-Saclay, CNRS, Institut de Chimie des Substances Naturelles, UPR 2301, 91198 Gif-sur-Yvette, France
| | - Elsa van Elslande
- Université Paris-Saclay, CNRS, Institut de Chimie des Substances Naturelles, UPR 2301, 91198 Gif-sur-Yvette, France
| | - Xavier Guinchard
- Université Paris-Saclay, CNRS, Institut de Chimie des Substances Naturelles, UPR 2301, 91198 Gif-sur-Yvette, France
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5
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Palmieri A, Petrini M. Synthesis and practical applications of 2-(2-nitroalkyl)pyrroles. Org Biomol Chem 2021; 18:4533-4546. [PMID: 32510092 DOI: 10.1039/d0ob00956c] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Functionalization of pyrroles introducing a 2-nitroalkyl moiety allows the formation of nitro-containing compounds to be used as pivotal intermediates for the synthesis of bioactive compounds. The reaction of pyrroles with nitroalkenes under the Friedel-Crafts conditions allows a direct entry to 2-(2-nitroalkyl)pyrroles. This approach can also be used for the preparation of enantioenriched derivatives exploiting asymmetric catalysis. In a complementary fashion, the Henry reaction between 2-formylpyrroles and nitroalkanes generates the corresponding nitroaldol products which upon dehydration and reduction of the intermediate 2-pyrrolylnitroethene efficiently afford 2-(2-nitroalkyl)pyrroles. This review article summarizes the most relevant procedures for the preparation of 2-(2-nitroalkyl)pyrroles during the last two decades as well as their significant practical applications.
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Affiliation(s)
- Alessandro Palmieri
- School of Science and Technology, Chemistry Division, University of Camerino, Via S. Agostino n. 1, 62032 Camerino (MC), Italy.
| | - Marino Petrini
- School of Science and Technology, Chemistry Division, University of Camerino, Via S. Agostino n. 1, 62032 Camerino (MC), Italy.
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6
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Boylan A, Nguyen TS, Lundy BJ, Li JY, Vallakati R, Sundstrom S, May JA. Rate Dependence on Inductive and Resonance Effects for the Organocatalyzed Enantioselective Conjugate Addition of Alkenyl and Alkynyl Boronic Acids to β-Indolyl Enones and β-Pyrrolyl Enones. Molecules 2021; 26:1615. [PMID: 33799473 PMCID: PMC8000498 DOI: 10.3390/molecules26061615] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 03/05/2021] [Accepted: 03/08/2021] [Indexed: 12/01/2022] Open
Abstract
Two key factors bear on reaction rates for the conjugate addition of alkenyl boronic acids to heteroaryl-appended enones: the proximity of inductively electron-withdrawing heteroatoms to the site of bond formation and the resonance contribution of available heteroatom lone pairs to stabilize the developing positive charge at the enone β-position. For the former, the closer the heteroatom is to the enone β-carbon, the faster the reaction. For the latter, greater resonance stabilization of the benzylic cationic charge accelerates the reaction. Thus, reaction rates are increased by the closer proximity of inductive electron-withdrawing elements, but if resonance effects are involved, then increased rates are observed with electron-donating ability. Evidence for these trends in isomeric substrates is presented, and the application of these insights has allowed for reaction conditions that provide improved reactivity with previously problematic substrates.
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Affiliation(s)
- Amy Boylan
- Department of Chemistry, University of Houston, 3585 Cullen Blvd., Fleming Building 112, Houston, TX 77204-5003, USA; (A.B.); (T.S.N.); (B.J.L.); (J.-Y.L.); (R.V.); (S.S.)
| | - Thien S. Nguyen
- Department of Chemistry, University of Houston, 3585 Cullen Blvd., Fleming Building 112, Houston, TX 77204-5003, USA; (A.B.); (T.S.N.); (B.J.L.); (J.-Y.L.); (R.V.); (S.S.)
- Graduate School of Energy, Environment, Water and Sustainability (EEWS), Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Korea
| | - Brian J. Lundy
- Department of Chemistry, University of Houston, 3585 Cullen Blvd., Fleming Building 112, Houston, TX 77204-5003, USA; (A.B.); (T.S.N.); (B.J.L.); (J.-Y.L.); (R.V.); (S.S.)
- Baker Hughes, 17021 Aldine Westfield Rd, Houston, TX 77073, USA
| | - Jian-Yuan Li
- Department of Chemistry, University of Houston, 3585 Cullen Blvd., Fleming Building 112, Houston, TX 77204-5003, USA; (A.B.); (T.S.N.); (B.J.L.); (J.-Y.L.); (R.V.); (S.S.)
- Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
| | - Ravikrishna Vallakati
- Department of Chemistry, University of Houston, 3585 Cullen Blvd., Fleming Building 112, Houston, TX 77204-5003, USA; (A.B.); (T.S.N.); (B.J.L.); (J.-Y.L.); (R.V.); (S.S.)
- Vallark Pharma Pvt. Ltd., Genome Valley, Turkapally, Hyderabad 500078, India
| | - Sasha Sundstrom
- Department of Chemistry, University of Houston, 3585 Cullen Blvd., Fleming Building 112, Houston, TX 77204-5003, USA; (A.B.); (T.S.N.); (B.J.L.); (J.-Y.L.); (R.V.); (S.S.)
- Department of Chemistry and Biochemistry, Baylor Sciences Bldg. D.208, One Bear Place #97348, Waco, TX 76798, USA
| | - Jeremy A. May
- Department of Chemistry, University of Houston, 3585 Cullen Blvd., Fleming Building 112, Houston, TX 77204-5003, USA; (A.B.); (T.S.N.); (B.J.L.); (J.-Y.L.); (R.V.); (S.S.)
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Yamada T, Hashimoto Y, Tanaka K, Morita N, Tamura O. Thioether Ligand-Enabled Cationic Palladium(II)-Catalyzed Electrophilic C-H Arylation of α,β-Unsaturated Oxime Ethers. J Org Chem 2020; 85:12315-12328. [PMID: 32844650 DOI: 10.1021/acs.joc.0c01570] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The use of the cationic palladium(II) catalyst realized electrophilic C-H arylation of α,β-unsaturated O-SEM oximes with arylboronic acids. This Pd-catalyzed electrophilic C-H arylation is facilitated by employing alkyl aryl thioether ligands, and optimization of the ligand structure greatly improves the yield. The resulting α,β-unsaturated oximes would provide access to multisubstituted heterocyclic compounds.
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Affiliation(s)
- Takahiro Yamada
- Showa Pharmaceutical University, Machida, Tokyo 194-8543, Japan
| | | | - Kosaku Tanaka
- Showa Pharmaceutical University, Machida, Tokyo 194-8543, Japan
| | | | - Osamu Tamura
- Showa Pharmaceutical University, Machida, Tokyo 194-8543, Japan
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Schlegel M, Schneider C. Iron(III)-Catalyzed (4 + 2)-Cycloannulation of 2-Hydroxy Ketoxime Ethers with Indol-2-ylamides: Synthesis of Indole-Fused 2-Piperidinones. J Org Chem 2019; 84:5886-5892. [PMID: 30917274 DOI: 10.1021/acs.joc.9b00261] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A highly regio- and diastereoselective (4 + 2)-cycloannulation process of indanone-derived 2-hydroxy ketoxime ethers with 1,4-bisnucleophilic indol-2-ylamides has been developed. In the presence of 5 mol % FeCl3, densely functionalized 2-piperidinones containing two new σ-bonds and two vicinal quaternary stereogenic centers were formed under mild reaction conditions in a one-pot operation. Moreover, most of the products directly precipitated out of the solution and were isolated by simple filtration without purification by column chromatography.
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Affiliation(s)
- Marcel Schlegel
- Institut für Organische Chemie , Universität Leipzig , Johannisallee 29 , D-04103 Leipzig , Germany
| | - Christoph Schneider
- Institut für Organische Chemie , Universität Leipzig , Johannisallee 29 , D-04103 Leipzig , Germany
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9
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Medran NS, La-Venia A, Testero SA. Metal-mediated synthesis of pyrrolines. RSC Adv 2019; 9:6804-6844. [PMID: 35518475 PMCID: PMC9061060 DOI: 10.1039/c8ra10247c] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Accepted: 02/18/2019] [Indexed: 12/21/2022] Open
Abstract
The five-membered, nitrogen-containing pyrroline ring is a privileged structure. This ring is present in many bioactive compounds from natural sources. Pyrrolines-the dihydro derivatives of pyrroles-have three structural isomer classes, depending on the location of the double bond: 1-pyrrolines (3,4-dihydro-2H-pyrroles), 2-pyrrolines (2,3-dihydro-1H-pyrroles) and 3-pyrrolines (2,5-dihydro-1H-pyrroles). This review aims to describe the latest advances for the synthesis of pyrrolines by transition metal-catalyzed cyclizations. Only reactions in which the pyrroline ring is formed by metal promotion are described. Transformations of the pyrroline ring in other heterocycles, and the structural manipulations of the pyrroline itself are not discussed. The review is organized into three parts, each covering the metal-mediated synthesis of the three pyrroline isomers. Each part is subdivided according to the metal involved, and concludes with a brief description of notable biological activities within the class.
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Affiliation(s)
- Noelia S Medran
- Instituto de Química Rosario - IQUIR (CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario Suipacha 531 Rosario S2002LRK Argentina http://www.iquir-conicet.gov.ar/eng/
| | - Agustina La-Venia
- Instituto de Química Rosario - IQUIR (CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario Suipacha 531 Rosario S2002LRK Argentina http://www.iquir-conicet.gov.ar/eng/
| | - Sebastian A Testero
- Instituto de Química Rosario - IQUIR (CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario Suipacha 531 Rosario S2002LRK Argentina http://www.iquir-conicet.gov.ar/eng/
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10
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Schlegel M, Schneider C. Lewis acid-catalyzed Friedel–Crafts reactions toward highly versatile, α-quaternary oxime ethers. Chem Commun (Camb) 2018; 54:11124-11127. [DOI: 10.1039/c8cc06823b] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Tertiary 2-hydroxy oxime ethers are converted into α-functionalized, all-carbon-substituted products under Lewis acid catalysis in a SN1-reaction.
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Affiliation(s)
- Marcel Schlegel
- Institut für Organische Chemie
- Universität Leipzig
- D-04103 Leipzig
- Germany
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