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Diradical-singlet character of 1,3-dipoles affects reactivity of 1,3-dipolar cycloaddition reactions and intramolecular cyclization. J Mol Model 2019; 25:306. [DOI: 10.1007/s00894-019-4162-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Accepted: 08/14/2019] [Indexed: 11/26/2022]
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2
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Jiang M, Feng L, Feng J, Jiao P. Catalytic Asymmetric Cycloadditions of Silyl Nitronates Bearing α-Aryl Group. Org Lett 2017; 19:2210-2213. [PMID: 28436671 DOI: 10.1021/acs.orglett.7b00558] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
1,3-Dipolar cycloadditions of 2-alkylacroleins or atropaldehyde with triisopropylsilyl nitronates bearing an α-aryl group produced 3-aryl-2-isoxazolines having a chiral quaternary center in up to 94% ee and up to 88% yield with the aid of Corey's oxazaborolidine catalyst. Specifically, the TIPS nitronate with an α-(p-methoxyphenyl) group gave mainly the 2-isoxazolines having an all-carbon quaternary center.
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Affiliation(s)
- Minghui Jiang
- Key Laboratory of Radiopharmaceuticals, College of Chemistry, Beijing Normal University , Beijing 100875, P. R. China
| | - Lifei Feng
- Key Laboratory of Radiopharmaceuticals, College of Chemistry, Beijing Normal University , Beijing 100875, P. R. China
| | - Juanjuan Feng
- Key Laboratory of Radiopharmaceuticals, College of Chemistry, Beijing Normal University , Beijing 100875, P. R. China
| | - Peng Jiao
- Key Laboratory of Radiopharmaceuticals, College of Chemistry, Beijing Normal University , Beijing 100875, P. R. China
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3
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Mochalov SS, Fedotov AN, Trofimova EV, Gazzaeva RA, Zefirov NS. Isomerization of 3-unsubstituted 4,5-dihydroisoxazoles over alumina. A new synthesis of β-hydroxy nitriles. RUSSIAN JOURNAL OF ORGANIC CHEMISTRY 2016. [DOI: 10.1134/s1070428016030179] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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4
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Dong L, Geng C, Jiao P. Silyl Nitronate Cycloadditions Catalyzed by Cu(II)-Bisoxazoline. J Org Chem 2015; 80:10992-1002. [DOI: 10.1021/acs.joc.5b02035] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Li Dong
- Key Laboratory of Radiopharmaceuticals,
Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
| | - Caiwei Geng
- Key Laboratory of Radiopharmaceuticals,
Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
| | - Peng Jiao
- Key Laboratory of Radiopharmaceuticals,
Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
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5
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Han X, Dong L, Geng C, Jiao P. Catalytic Asymmetric Synthesis of Isoxazolines from Silyl Nitronates. Org Lett 2015; 17:3194-7. [DOI: 10.1021/acs.orglett.5b00826] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Xiaoyu Han
- Key Laboratory
of Radiopharmaceuticals, College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
| | - Li Dong
- Key Laboratory
of Radiopharmaceuticals, College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
| | - Caiwei Geng
- Key Laboratory
of Radiopharmaceuticals, College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
| | - Peng Jiao
- Key Laboratory
of Radiopharmaceuticals, College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
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7
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Zeng Y, Liu F. 1,3-Dipolar Cycloaddition in the Synthesis of Novel Isoxazoline/Pyrazole Derivatives Bearing 1,2,3-Triazoles Moiety. J Heterocycl Chem 2013. [DOI: 10.1002/jhet.1527] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
| | - Fangming Liu
- College of Materials and Chemical Engineering; Hangzhou Normal University; Hangzhou; 310036; People's Republic of China
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Pohjakallio A, Pihko PM, Liu J. Base-Catalyzed Isomerization of 2-Isoxazolines Enables a Two-Step Enantioselective Synthesis of β-Hydroxynitriles from Enals. J Org Chem 2010; 75:6712-5. [DOI: 10.1021/jo1013788] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Antti Pohjakallio
- Department of Chemistry, Aalto University School of Science and Technology, Kemistintie 1, FI-02150 Espoo, Finland
| | - Petri M. Pihko
- Department of Chemistry, University of Jyväskylä, FI-40014 JYU, Finland
| | - Jun Liu
- Department of Chemistry, University of Jyväskylä, FI-40014 JYU, Finland
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10
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Gefflaut T, Martin C, Delor S, Besse P, Veschambre H, Bolte J. Deoxysugars via microbial reduction of 5-acyl-isoxazolines: application to the synthesis of 3-deoxy-D-fructose and derivatives. J Org Chem 2001; 66:2296-301. [PMID: 11281769 DOI: 10.1021/jo001480f] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
5-Acylisoxazolines 3a-d were obtained by 1,3-dipolar cycloaddition from acetoxymethyl vinyl ketone and nitro precursors. Compounds 3a-d were biotransformed by Aspergillus niger into a 1:1 mixture of stereomers of 5-dihydroxyethyl isoxazolines (+)-4a-d (anti) and (-)-5a-d (syn). Both stereomers were obtained in good yields and with high optical purities. Carbonyl reduction by Aspergillus niger produces alcohols of R-configuration thus giving an access to D-sugar analogues: Compound (+)-4d was converted to 3-deoxy-D-erythro-hexulose and several protected derivatives. Total synthesis of 3-deoxy-D-fructose-6-phosphate was also achieved in two steps and 64% overall yield from (+)-4d.
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Affiliation(s)
- T Gefflaut
- Université Blaise Pascal, Laboratoire SEESIB, UMR 6504, 63177 Aubière Cedex, France.
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12
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García-Expósito E, González-Moreno R, Martín-Vilà M, Muray E, Rifé J, Bourdelande JL, Branchadell V, Ortuño RM. On the Z-E photoisomerization of chiral 2-pentenoate esters: stationary irradiations, laser-flash photolysis studies, and theoretical calculations. J Org Chem 2000; 65:6958-65. [PMID: 11031016 DOI: 10.1021/jo000549g] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Chiral pentenoates 1-3 in both Z and E isomeric forms underwent stationary irradiations in several solvents and in the presence of different photosensitizers. The photostationary-state ratio has been determined for each Z/E couple showing a predominance of the thermodynamically more stable isomer for 1 and 3. Moreover, transient species were generated by pulsed laser excitation and detected by their characteristic ultraviolet absorptions, being the first time that enoate-originated triplets are detected. Stern-Volmer quenching studies afforded a quantitative measure for the efficiency of the photosensitization processes induced by benzophenone or acetophenone and allowed the determination of the corresponding quenching rate constants. Density functional calculations permitted the determination of the geometries and the energies of the diastereomeric excited states. Two diastereomeric orthogonal and two diastereomeric planar structures result as a consequence of the presence of a chiral substituent. The orthogonal triplets are the energy minima in all cases, whereas the planar triplets are the transition states linking these orthogonal structures, the corresponding energy barriers being 8-10 kcal mol(-1) for enoates 1-3. The computed S(0) to T(1) excitation energies show a trend which is consistent with the quenching rate constants. On the other hand, the triplet lifetimes determined for 1 and 2 are unusually long (1-20 micros) if compared with the data already described for several enones, in the range of nanoseconds. This fact has been rationalized from calculations of spin-orbit coupling at several points of the T(1) potential energy surface. This coupling is maximum for structures with a torsional angle close to 45 degrees, which are 4-5 kcal mol(-1) above the minima of T(1). Calculations done on the hypothetical aldehyde 4 and methyl vinyl ketone show much lower energy barriers, thus accounting for the shorter lifetimes reported for enone triplets.
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Affiliation(s)
- E García-Expósito
- Departament de Química, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain
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13
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1,3-Dipolar cycloadditions of diazomethane to chiral electron-deficient olefins: the origin of the pi-facial diastereoselection. J Org Chem 2000; 65:388-96. [PMID: 10813946 DOI: 10.1021/jo991227j] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The stereochemical outcome of diazomethane cycloadditions to several chiral electron-deficient olefins has been investigated in order to establish the origin of the pi-facial diastereoselection. Nitro olefins, vinyl sulfones, enoates, and 2-amino enoates have been used for such a purpose. These substrates have been prepared from D-glyceraldehyde acetonide through Wittig-type condensations and present an alkoxy substituent, provided by the bulky dioxolane ring, attached to the stereogenic allylic carbon. Syn-adducts have been obtained in all cases as the major isomers, independently of the Z/E stereochemistry of the double bond and the number and the nature of the substituents, the chirality of the asymmetric allylic carbon being the only thing responsible for the diastereoselection. Theoretical calculations show that steric hindrance due to the bulky dioxolane group is the main factor governing the preference for the syn-attack of diazomethane to the olefinic double bond.
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KANEMASA S. Stereo- and Regio-Control of 1, 3-Dipolar Cycloaddition Reactions by the Aid of Lewis Acid Catalysts—Nitrone and aci-Nitro Compound Cycloadditions—. ACTA ACUST UNITED AC 2000. [DOI: 10.1246/nikkashi.2000.155] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Shuji KANEMASA
- Institute of Advanced Material Study, Kyushu University; 6-1 Kasugakoen, Kasuga-shi 816-8580 Japan
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Annunziata R, Benaglia M, Cinquini M, Cozzi F, Raimondi L. The Importance of Electrostatic Interactions in the Stereoselective 1,3-Dipolar Cycloadditions of Nitrones to Chiral Allyl Ethers: An Experimental and Force Field Approach. European J Org Chem 1998. [DOI: 10.1002/(sici)1099-0690(199809)1998:9<1823::aid-ejoc1823>3.0.co;2-h] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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16
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Martín-Vilà M, Hanafi N, Jiménez JM, Alvarez-Larena A, Piniella JF, Branchadell V, Oliva A, Ortuño RM. Controlling π-Facial Diastereoselectivity in the 1,3-Dipolar Cycloadditions of Diazomethane to Chiral Pentenoates and Furanones: Enantioselective Stereodivergent Syntheses of Cyclopropane Hydroxy Acids and Didehydro Amino Acids. J Org Chem 1998. [DOI: 10.1021/jo972219a] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Marta Martín-Vilà
- Departament de Química and Unitat de Cristal.lografia, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain
| | - Neuh Hanafi
- Departament de Química and Unitat de Cristal.lografia, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain
| | - José M. Jiménez
- Departament de Química and Unitat de Cristal.lografia, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain
| | - Angel Alvarez-Larena
- Departament de Química and Unitat de Cristal.lografia, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain
| | - Joan F. Piniella
- Departament de Química and Unitat de Cristal.lografia, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain
| | - Vicenç Branchadell
- Departament de Química and Unitat de Cristal.lografia, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain
| | - Antonio Oliva
- Departament de Química and Unitat de Cristal.lografia, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain
| | - Rosa M. Ortuño
- Departament de Química and Unitat de Cristal.lografia, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain
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Affiliation(s)
- Kurt V. Gothelf
- Center for Metal Catalyzed Reactions, Department of Chemistry, Aarhus University, DK-8000 Aarhus C, Denmark
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Jensen KB, Gothelf KV, Hazell RG, Jørgensen KA. Improvement of TADDOLate-TiCl(2)-Catalyzed 1,3-Dipolar Nitrone Cycloaddition Reactions by Substitution of the Oxazolidinone Auxiliary of the Alkene with Succinimide. J Org Chem 1997; 62:2471-2477. [PMID: 11671584 DOI: 10.1021/jo962214y] [Citation(s) in RCA: 96] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A significant improvement of metal-catalyzed asymmetric 1,3-dipolar cycloaddition reactions of acyclic nitrones with alpha,beta-unsaturated carbonyl compounds is described using succinimide as a new auxiliary for the alpha,beta-unsaturated carbonyl moiety. In the absence of a catalyst, N-crotonoylsuccinimide reacts with C,N-diphenylnitrone to give the endo-isoxazolidine, whereas in the presence of 10 mol % TiCl(2)(i-PrO)(2) the exo-product is obtained. Four different TiCl(2)-TADDOLate complexes have been tested as catalysts for the 1,3-dipolar cycloaddition reactions, and the most successful catalyst was applied (5 mol %) in a series of reactions between two different alkenoylsuccinimides and three different nitrones. The crude products containing an N-acylsuccinimide moiety were converted directly into the corresponding carboxamides upon treatment with hydrazine. The 1,3-dipolar cycloaddition reactions proceed with a high degree of exo-selectivity, often >90% de, which is an improvement compared with previous experiments performed using the oxazolidinone auxiliary for the alkenoyl moiety. Furthermore, the enantioselectivities are also improved compared with previous work, and ee up to 73% is obtained, which is the highest ee found for these metal-catalyzed exo-selective 1,3-dipolar cycloaddition reactions. The ee can be improved to >90% by recrystallization. The absolute structure of the 1,3-dipolar cycloaddition adduct is determined on the basis of the X-ray crystal structure of a compound with a known configuration. On the basis of this knowledge of the absolute structure of the product the mechanism of the reaction is briefly discussed.
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Affiliation(s)
- Kim B. Jensen
- Department of Chemistry, Aarhus University, DK-8000 Aarhus C, Denmark
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