1
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Yuan A, Steber SE, Xhili D, Nelson E, Wolf C. Enantioseparation and racemization of 3-fluorooxindoles. Chirality 2023; 35:619-624. [PMID: 37129272 PMCID: PMC10516598 DOI: 10.1002/chir.23572] [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: 01/09/2023] [Revised: 04/03/2023] [Accepted: 04/17/2023] [Indexed: 05/03/2023]
Abstract
Fluorinated oxindoles are frequently used building blocks in asymmetric synthesis and represent an important scaffold found in a variety of biologically relevant compounds. While it is understood that incorporation of fluorine atoms into organic molecules can improve their pharmacological properties, the impact on the configurational stability of chiral organofluorines is still underexplored. In this study, semipreparative HPLC enantioseparations of five oxindoles were carried out, and the resulting enantiomerically enriched solutions were used to investigate base promoted racemization kinetics at room temperature. It was found that incorporation of fluorine at the chiral center increases the configurational stability, while substitutions on the aromatic ring and at the lactam moiety also have significant effects on the rate of racemization, which generally follows reversible first-order reaction kinetics.
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Affiliation(s)
- Andi Yuan
- Department of Chemistry, Georgetown University, Washington, DC, USA
| | - Sarah E Steber
- Department of Chemistry, Georgetown University, Washington, DC, USA
| | - Dea Xhili
- Department of Chemistry, Georgetown University, Washington, DC, USA
| | - Eryn Nelson
- Department of Chemistry, Georgetown University, Washington, DC, USA
| | - Christian Wolf
- Department of Chemistry, Georgetown University, Washington, DC, USA
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2
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Figula BC, Kane DL, Balaraman K, Wolf C. Organocuprate Cross-Coupling Reactions with Alkyl Fluorides. Org Lett 2022; 24:8719-8723. [PMID: 36394939 PMCID: PMC10502612 DOI: 10.1021/acs.orglett.2c03775] [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] [Indexed: 11/18/2022]
Abstract
Cross-coupling of alkyl fluorides and organocuprates is accomplished via aluminum halide mediated C-F bond activation and subsequent Csp2-Csp3 and Csp3-Csp3 bond formation. Relatively mild conditions allow for smooth activation of notoriously challenging primary and secondary alkyl fluorides while competing alkyl chain rearrangement, HF elimination, and homocoupling reactions are effectively controlled. The utility and functional group tolerance are demonstrated with 23 examples and a variety of coupling products obtained in up to 88% yield.
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Affiliation(s)
- Bryan C Figula
- Chemistry Department, Georgetown University, Washington, DC 20057, United States
| | - D Lucas Kane
- Chemistry Department, Georgetown University, Washington, DC 20057, United States
| | - Kaluvu Balaraman
- Chemistry Department, Georgetown University, Washington, DC 20057, United States
| | - Christian Wolf
- Chemistry Department, Georgetown University, Washington, DC 20057, United States
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3
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Balaraman K, Kyriazakos S, Palmer R, Thanzeel FY, Wolf C. Selective Csp 3-F Bond Functionalization with Lithium Iodide. SYNTHESIS-STUTTGART 2022; 54:4320-4328. [PMID: 36330045 PMCID: PMC9624501 DOI: 10.1055/s-0041-1738383] [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] [Indexed: 10/18/2022]
Abstract
A highly efficient method for C-F bond functionalization of a broad variety of activated and unactivated aliphatic substrates with inexpensive lithium iodide is presented. Primary, secondary, tertiary, benzylic, propargylic and α-functionalized alkyl fluorides react in chlorinated or aromatic solvents at room temperature or upon heating to the corresponding iodides which are isolated in 91-99% yield. The reaction is selective for aliphatic monofluorides and can be coupled with in situ nucleophilic iodide replacements to install carbon-carbon, carbon-nitrogen and carbon-sulfur bonds with high yields. Alkyl difluorides, trifluorides, even in activated benzylic positions, are inert under the same conditions and aryl fluoride bonds are also tolerated.
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Affiliation(s)
- Kaluvu Balaraman
- Georgetown University, Chemistry Department, Washington, DC 20057, USA
| | | | - Rachel Palmer
- Georgetown University, Chemistry Department, Washington, DC 20057, USA
| | - F Yushra Thanzeel
- Georgetown University, Chemistry Department, Washington, DC 20057, USA
| | - Christian Wolf
- Georgetown University, Chemistry Department, Washington, DC 20057, USA
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4
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Balaraman K, Wolf C. Chemodivergent Csp 3─F bond functionalization and cross-electrophile alkyl-alkyl coupling with alkyl fluorides. SCIENCE ADVANCES 2022; 8:eabn7819. [PMID: 35622926 PMCID: PMC9140971 DOI: 10.1126/sciadv.abn7819] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The widespread use of fluorinated organic compounds in the health, agrochemical, and materials sciences is sustained by a steadily growing pool of commercially available fine chemicals. The synthetic utility of the increasingly ubiquitous Csp3─F bond, however, remains to be fully exploited, which is often a difficult task because of its paramount stability and chemical inertness. Here, we demonstrate chemodivergent activation of monofluoroalkyl compounds toward either nucleophilic or electrophilic intermediates. This is accomplished under conditions that are compatible with several reaction types and many functional groups, which drastically widens the current scope of organofluorine chemistry and sets the stage for carbon-carbon and carbon-heteroatom bond formations, stereoselective construction of bisoxindole alkaloid scaffolds via in situ Umpolung, and cross-electrophilic coupling methodology. The selective generation of either nucleophilic or electrophilic species and the possibility of doing so simultaneously or, alternatively, switching molecular polarity enable previously unidentified synthetic opportunities that recognize alkyl fluorides as chemodivergent building blocks.
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5
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Lei ZL, Huang DK, Liu Q, Chen HY, Gao YN, Liu JT, Liu ZJ. Decarboxylative aldol reaction of α,α-difluoro-β-keto acids and isatins: A facile synthesis of 3-difluoroalkyl-3-hydroxyoxindole derivatives. J Fluor Chem 2022. [DOI: 10.1016/j.jfluchem.2021.109930] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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6
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Balaraman K, Wolf C. Palladium and Nickel Catalyzed Suzuki Cross-Coupling with Alkyl Fluorides. Org Lett 2021; 23:8994-8999. [PMID: 34723542 DOI: 10.1021/acs.orglett.1c03515] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Suzuki cross-coupling of benzylic and unactivated aliphatic fluorides with aryl- and alkenylboronic acids has been achieved via mechanistically distinct Pd and Ni catalyzed pathways that outperform competing protodeboronation, β-hydride elimination, and homocoupling processes. The utility is demonstrated with more than 20 examples including heterocyclic structures, 1,1-disubstituted and trans-1,2-disubstituted alkenes, and by the incorporation of acetonitrile into functionalized (hetero)arenes.
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Affiliation(s)
- Kaluvu Balaraman
- Georgetown University, Chemistry Department, Washington, District of Columbia 20057, United States
| | - Christian Wolf
- Georgetown University, Chemistry Department, Washington, District of Columbia 20057, United States
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7
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Steber SE, Pham ANDL, Nelson E, Wolf C. Enantioseparation and racemization of α-aryl-α-fluoroacetonitriles. Chirality 2021; 33:891-898. [PMID: 34598313 DOI: 10.1002/chir.23367] [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] [Received: 08/05/2021] [Revised: 09/02/2021] [Accepted: 09/12/2021] [Indexed: 12/15/2022]
Abstract
The 2-Aryl-2-fluoroacetonitriles have garnered increasing interest as versatile building blocks in asymmetric synthesis. However, the configurational stability of these organofluorines is poorly understood and analytical methods that can be used to differentiate between their enantiomers remain underdeveloped. In this study, baseline high performance liquid chromatography (HPLC) enantioseparation of ten 2-aryl-2-fluoroacetonitriles was achieved by screening frequently used chiral stationary phases. While Chiralcel OD, Chiralpak AD, and Chiralpak AS proved to be most broadly useful, preparative separation of the enantiomers of 2-(2-naphthyl)-2-fluoroacetonitrile was possible on Chiralcel OJ. This enabled racemization studies at various temperatures and in the presence of organic bases which showed that this compound is configurationally stable under neutral conditions upon heating to 130°C for 6 h but undergoes complete racemization within 10 h in the presence of stoichiometric amounts of a guanidine base at room temperature. The racemization is likely to proceed via formation of an achiral keteniminate intermediate and obeys reversible first-order reaction kinetics with a half-life time of 87.7 min in ethanolic hexanes at 23.2°C. Racemization is significantly slower and occurs with a half-life time of 23.1 h at 22.4°C when the guanidine is replaced with a weaker amidine base.
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Affiliation(s)
- Sarah E Steber
- Department of Chemistry, Georgetown University, Washington, District of Columbia, USA
| | - Angelette N D L Pham
- Department of Chemistry, Georgetown University, Washington, District of Columbia, USA
| | - Eryn Nelson
- Department of Chemistry, Georgetown University, Washington, District of Columbia, USA
| | - Christian Wolf
- Department of Chemistry, Georgetown University, Washington, District of Columbia, USA
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8
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Capilato JN, Pellegrinelli PJ, Bernard J, Schnorbus L, Philippi S, Mattiucci J, Hoy EP, Perez LJ. Acetyl nitrate mediated conversion of methyl ketones to diverse carboxylic acid derivatives. Org Biomol Chem 2021; 19:5298-5302. [PMID: 34086029 DOI: 10.1039/d1ob00786f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The development of a novel acetyl nitrate mediated oxidative conversion of methyl ketones to carboxylic acid derivatives is described. By analogy to the haloform reaction and supported by experimental and computational investigation we propose a mechanism for this transformation.
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Affiliation(s)
- Joseph N Capilato
- Rowan University, Department of Chemistry & Biochemistry, 201 Mullica Hill Rd., Glassboro, NJ 08028, USA.
| | - Peter J Pellegrinelli
- Rowan University, Department of Chemistry & Biochemistry, 201 Mullica Hill Rd., Glassboro, NJ 08028, USA.
| | - Josephine Bernard
- Rowan University, Department of Chemistry & Biochemistry, 201 Mullica Hill Rd., Glassboro, NJ 08028, USA.
| | - Logan Schnorbus
- Rowan University, Department of Chemistry & Biochemistry, 201 Mullica Hill Rd., Glassboro, NJ 08028, USA.
| | - Shane Philippi
- Rowan University, Department of Chemistry & Biochemistry, 201 Mullica Hill Rd., Glassboro, NJ 08028, USA.
| | - Joseph Mattiucci
- Rowan University, Department of Chemistry & Biochemistry, 201 Mullica Hill Rd., Glassboro, NJ 08028, USA.
| | - Erik P Hoy
- Rowan University, Department of Chemistry & Biochemistry, 201 Mullica Hill Rd., Glassboro, NJ 08028, USA.
| | - Lark J Perez
- Rowan University, Department of Chemistry & Biochemistry, 201 Mullica Hill Rd., Glassboro, NJ 08028, USA.
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9
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Xu L, Zhang WH, Cui ZS, Zhang ZH. Choline Chloride/Glycerol Promoted Synthesis of 3,3-Disubstituted Indol-2-ones. CURRENT ORGANOCATALYSIS 2021. [DOI: 10.2174/2213337207999210104223005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Objective:
3,3-Disubstituted indol-2-one derivatives have wider applications in pharmaceuticals and they are key intermediates for the synthesis of many kinds of drug candidates. The development of an efficient and practical method to prepare this class of compound is highly desirable from both environmental and economical points of views.
Methods:
In order to establish an effective synthetic method for preparing 3,3-disubstituted indol-2-one derivatives, the bis-condensation reaction of isatin and 1H-indene-1,3(2H)-dione was selected as a model reaction. A variety of natural deep eutectic solvent (NADES) were prepared and used for this reaction. The generality and limitation of the established method were also investigated.
Results:
It was found that model reaction can be carried out in natural deep eutectic solvent (NADES) based on choline chloride (ChCl) at 80 oC under microwave irradiation. This protocol with a broad substrate applicability afforded various 2,2'-(2-oxoindoline-3,3-diyl)bis(1H-indene-1,3(2H)-dione) derivatives in high yields.
Conclusion:
simple and efficient procedure has been developed for synthesis of 2,2'-(2-oxoindoline-3,3-diyl)bis(1H-indene-1,3(2H)-dione), spiro[indoline-3,7'-pyrano[5,6-c:5,6-c']dichromene]-2,6',8'-trione, and spiro[indoline-3,9'-xan-thene] trione via bis-condensation between isatin with 1,3-indandione, 4-hydroxycoumarin or 1,3-cyclohexanedione in nat-ural deep eutectic solvent (NADES) based on choline chloride (ChCl) and glycerol (Gl) under microwave irradiation. The salient features of this protocol are avoidance of any additive/catalyst and toxic organic solvent, clean reaction profiles, non-chromatographic purification procedure, and high to excellent yield. Furthermore, the use of NADES as green reaction medium reduces burden on environment and makes the present method environmentally sustainable.
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Affiliation(s)
- Ling Xu
- Hebei Key Laboratory of Organic Functional Molecules, National Demonstration Center for Experimental Chemistry Education, College of Chemistry and Material Science, Hebei Normal University, Shijiazhuang 050024,, China
| | - Wei-Hong Zhang
- Hebei Key Laboratory of Organic Functional Molecules, National Demonstration Center for Experimental Chemistry Education, College of Chemistry and Material Science, Hebei Normal University, Shijiazhuang 050024,, China
| | - Zhen-Shui Cui
- Hebei Key Laboratory of Organic Functional Molecules, National Demonstration Center for Experimental Chemistry Education, College of Chemistry and Material Science, Hebei Normal University, Shijiazhuang 050024,, China
| | - Zhan-Hui Zhang
- Hebei Key Laboratory of Organic Functional Molecules, National Demonstration Center for Experimental Chemistry Education, College of Chemistry and Material Science, Hebei Normal University, Shijiazhuang 050024,, China
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10
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Zhang Y, Ge J, Luo L, Yan SQ, Lai GW, Mei ZQ, Luo HQ, Fan XL. Difluoroisoxazolacetophenone: A Difluoroalkylation Reagent for Organocatalytic Vinylogous Nitroaldol Reactions of 1,2-Diketones. Org Lett 2020; 22:7952-7957. [PMID: 32991188 DOI: 10.1021/acs.orglett.0c02873] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Difluoroisoxazolacetophenone (DFIO) is developed as a new difluoroalkylation reagent that can be easily prepared from inexpensive starting materials. In situ remote C-C bond cleavage of DFIO affords γ,γ-difluoroisoxazole nitronate that undergoes base-catalyzed vinylogous nitroaldol additions to isatins, benzothiophene-2,3-dione, unsaturated-α-ketoesters, and cyclic 1,2-diketones. This organocatalytic debenzoate vinylogous nitroaldol reaction provides a new and mild approach for the preparation of various difluoroisoxazole-substituted 3-hydroxy-2-oxindoles.
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Affiliation(s)
- Yong Zhang
- Key Laboratory of Organo-pharmaceutical Chemistry, Gannan Normal University, Ganzhou 341000, P.R. China
| | - Jin Ge
- Key Laboratory of Organo-pharmaceutical Chemistry, Gannan Normal University, Ganzhou 341000, P.R. China
| | - Liang Luo
- Key Laboratory of Organo-pharmaceutical Chemistry, Gannan Normal University, Ganzhou 341000, P.R. China
| | - Su-Qiong Yan
- Key Laboratory of Organo-pharmaceutical Chemistry, Gannan Normal University, Ganzhou 341000, P.R. China
| | - Guo-Wei Lai
- Key Laboratory of Organo-pharmaceutical Chemistry, Gannan Normal University, Ganzhou 341000, P.R. China
| | - Zu-Qin Mei
- Key Laboratory of Organo-pharmaceutical Chemistry, Gannan Normal University, Ganzhou 341000, P.R. China
| | - Hai-Qing Luo
- Key Laboratory of Organo-pharmaceutical Chemistry, Gannan Normal University, Ganzhou 341000, P.R. China
| | - Xiao-Lin Fan
- Key Laboratory of Organo-pharmaceutical Chemistry, Gannan Normal University, Ganzhou 341000, P.R. China
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11
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Axelsson A, Hammarvid E, Rahm M, Sundén H. DBU‐Catalyzed Ring‐Opening and Retro‐Claisen Fragmentation of Dihydropyranones. European J Org Chem 2020. [DOI: 10.1002/ejoc.202000858] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Anton Axelsson
- Chemistry and Chemical Engineering Chalmers University of Technology Kemivägen 10 412 96 Göteborg Sweden
| | - Emmelie Hammarvid
- Chemistry and Chemical Engineering Chalmers University of Technology Kemivägen 10 412 96 Göteborg Sweden
| | - Martin Rahm
- Chemistry and Chemical Engineering Chalmers University of Technology Kemivägen 10 412 96 Göteborg Sweden
| | - Henrik Sundén
- Chemistry and Chemical Engineering Chalmers University of Technology Kemivägen 10 412 96 Göteborg Sweden
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12
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High diastereoselective [4 + 2] annulation of β,γ-unsaturated α-keto esters and p-quinone methides: Approach to polysubstituted 4-aryl chromans and tetrahydroquinolines. Tetrahedron Lett 2020. [DOI: 10.1016/j.tetlet.2020.152171] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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13
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Lynch CC, Balaraman K, Wolf C. Catalytic Asymmetric Allylic Amination with Isatins, Sulfonamides, Imides, Amines, and N-Heterocycles. Org Lett 2020; 22:3180-3184. [PMID: 32255635 PMCID: PMC7369029 DOI: 10.1021/acs.orglett.0c00936] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
A generally useful palladium-catalyzed method for the asymmetric allylic amination with a large variety of isatins, sulfonamides, imides, amines, and N-heterocycles is introduced. A single protocol with a readily available catalyst accomplishes this reaction at room temperature with high yields and enantioselectivities often exceeding 90%, which is demonstrated with 31 examples.
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Affiliation(s)
- Ciarán C Lynch
- Department of Chemistry, Georgetown University, 37th and O Streets, Washington, DC 20057, United States
| | - Kaluvu Balaraman
- Department of Chemistry, Georgetown University, 37th and O Streets, Washington, DC 20057, United States
| | - Christian Wolf
- Department of Chemistry, Georgetown University, 37th and O Streets, Washington, DC 20057, United States
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14
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Deng Q, Mu F, Qiao Y, Wei D. A theoretical review for novel Lewis base amine/imine-catalyzed reactions. Org Biomol Chem 2020; 18:6781-6800. [DOI: 10.1039/d0ob01378a] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Recent advances in computational investigations of Lewis base amine/imine-catalyzed reactions have been systematically summarized and reviewed for the first time.
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Affiliation(s)
- Qianqian Deng
- College of Chemistry
- and Institute of Green Catalysis
- Zhengzhou University
- Zhengzhou
- China
| | - Fangjing Mu
- College of Chemistry
- and Institute of Green Catalysis
- Zhengzhou University
- Zhengzhou
- China
| | - Yan Qiao
- Department of Pathophysiology
- School of Basic Medical Sciences
- Zhengzhou University
- Zhengzhou
- China
| | - Donghui Wei
- College of Chemistry
- and Institute of Green Catalysis
- Zhengzhou University
- Zhengzhou
- China
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15
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Thanzeel FY, Balaraman K, Wolf C. Streamlined Asymmetric Reaction Development: A Case Study with Isatins. Chemistry 2019; 25:11020-11025. [DOI: 10.1002/chem.201902688] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 07/08/2019] [Indexed: 12/31/2022]
Affiliation(s)
- F. Yushra Thanzeel
- Department of Chemistry Georgetown University 37th and O Streets Washington DC 20057 USA
| | - Kaluvu Balaraman
- 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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16
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Mao K, Dai L, Liu Y, Rong L. An Efficient Five‐Component Reaction for the Synthesis of 4,4′‐((2‐Oxoindoline‐3,3‐diyl)bis(methylene))bis(2‐aryl‐1
H
‐pyrrolo[3,4‐
c
]quinoline‐1,3(2
H
)‐dione) Derivatives. J Heterocycl Chem 2019. [DOI: 10.1002/jhet.3592] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Kaimin Mao
- Jiangsu Key Laboratory of Green Synthetic Chemistry for Functional Materials, School of Chemistry and Materials ScienceJiangsu Normal University Xuzhou Jiangsu 221116 People's Republic of China
| | - Lei Dai
- Jiangsu Key Laboratory of Green Synthetic Chemistry for Functional Materials, School of Chemistry and Materials ScienceJiangsu Normal University Xuzhou Jiangsu 221116 People's Republic of China
| | - Yun Liu
- Jiangsu Key Laboratory of Green Synthetic Chemistry for Functional Materials, School of Chemistry and Materials ScienceJiangsu Normal University Xuzhou Jiangsu 221116 People's Republic of China
| | - Liangce Rong
- Jiangsu Key Laboratory of Green Synthetic Chemistry for Functional Materials, School of Chemistry and Materials ScienceJiangsu Normal University Xuzhou Jiangsu 221116 People's Republic of China
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17
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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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18
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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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19
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Abstract
This review summarizes the recent developments of the reactions of α-nitroketones and the consequent formation of a variety of structural frameworks is discussed.
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Affiliation(s)
- Chandan Gharui
- Department of Chemistry
- Indian Institute of Technology Guwahati
- India
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20
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Mei H, Liu J, Fustero S, Román R, Ruzziconi R, Soloshonok VA, Han J. Chemistry of detrifluoroacetylativelyin situgenerated fluoro-enolates. Org Biomol Chem 2019; 17:762-775. [DOI: 10.1039/c8ob02843e] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This review article provides a summary of the detrifluoroacetylativein situgeneration of fluorine-containing enolates and their related reactions.
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Affiliation(s)
- Haibo Mei
- College of Chemical Engineering
- Nanjing Forestry University
- Nanjing
- China
| | - Jiang Liu
- College of Chemical Engineering
- Nanjing Forestry University
- Nanjing
- China
| | - Santos Fustero
- Departamento de Química Orgánica
- Universidad de Valencia
- 46100 Burjassot
- Spain
- Laboratorio de Moléculas Orgánicas
| | - Raquel Román
- Departamento de Química Orgánica
- Universidad de Valencia
- 46100 Burjassot
- Spain
- Laboratorio de Moléculas Orgánicas
| | - Renzo Ruzziconi
- Department of Chemistry
- Biology and Biotechnologies
- 06123 Perugia
- Italy
| | - Vadim A. Soloshonok
- Department of Organic Chemistry I
- Faculty of Chemistry
- University of the Basque Country UPV/EHU
- 20018 San Sebastián
- Spain
| | - Jianlin Han
- College of Chemical Engineering
- Nanjing Forestry University
- Nanjing
- China
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21
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Mudithanapelli C, Vasam CS, Vadde R, Kim MH. Highly Efficient and Practical N-Heterocyclic Carbene Organocatalyzed Chemoselective N 1/C 3-Functionalization of Isatins with Green Chemistry Principles. ACS OMEGA 2018; 3:17646-17655. [PMID: 31458364 PMCID: PMC6643579 DOI: 10.1021/acsomega.8b02361] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Accepted: 12/04/2018] [Indexed: 06/10/2023]
Abstract
Ecofriendly N-heterocyclic carbene (NHC) organocatalysis can control the N1-functionalization (aza-Michael addition) and C3-functionalization (Morita-Baylis-Hillman reaction, MBH) of isatins in the absence of (1) a protecting group, (2) a stoichiometric reagent, and (3) heat energy. The challengeable N1-functionalization of N-unsubstituted isatins into N-substituted (NS) isatins was realized through 10 mol % NHC and 10 mol % 1,8-diazabicyclo[5.4.0]undec-7-ene catalysts within 10 min with up to 98% isolation yield. The subsequent MBH adducts of as-synthesized NS-isatins (N1/C3-functionalization) was perfectly acquired in 10 mol % NHC and 10 mol % 1,4-diazabicyclo[2.2.2]octane catalysis within 30 min with superiority to C3/N1-functionalization (MBH/aza-Michael). For guiding the application to a versatile druggable isatin library, the NHC catalysis was compared with reported functionalization of isatins in view of green chemistry principles including solvent scoring of ACS GCI pharmaceutical roundtable, E-factor, atom economy, and so on.
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Affiliation(s)
- Chandrashekar Mudithanapelli
- Gachon
Institute of Pharmaceutical Science & Department of Pharmacy,
College of Pharmacy, Gachon University, 191 Hambakmoeiro, Yeonsu-gu, Incheon 21936, Republic of Korea
- Department
of Chemistry, Kakatiya University, Warangal 506009, India
| | - Chandra Sekhar Vasam
- Department
of Pharmaceutical Chemistry, Telangana University, Nizamabad 503322, India
| | - Ravinder Vadde
- Department
of Chemistry, Kakatiya University, Warangal 506009, India
| | - Mi-hyun Kim
- Gachon
Institute of Pharmaceutical Science & Department of Pharmacy,
College of Pharmacy, Gachon University, 191 Hambakmoeiro, Yeonsu-gu, Incheon 21936, Republic of Korea
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22
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Gao FT, Fang Z, Su RR, Rui PX, Hu XG. Hydroximoyl fluorides as the precursors of nitrile oxides: synthesis, stability and [3 + 2]-cycloaddition with alkynes. Org Biomol Chem 2018; 16:9211-9217. [PMID: 30468229 DOI: 10.1039/c8ob02721h] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The transformation of hydroximoyl fluorides to nitrile oxides for [3 + 2]-cycloaddition with alkynes has been achieved for the first time. The hydroximoyl fluorides used in this work appeared to be not stable, which was proved by a series of experiments. A DFT calculation was performed to better understand the properties of hydroximoyl fluorides. Although not stable, the hydroximoyl fluorides could be successfully converted to the corresponding nitrile oxides for in situ [3 + 2]-cycloaddition with alkynes to yield the isoxazoles. Furthermore, it was feasible to conduct [3 + 2]-cycloaddition reaction without purification after the synthesis of hydroximoyl fluorides from gem-difluoroalkenes. By investigating a class of interesting yet previously rarely explored fluorinated compounds, this work sheds new light on the stability and reactivity of a C-F bond on a C[double bond, length as m-dash]N double bond.
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Affiliation(s)
- Feng-Teng Gao
- National Engineering Research Center for Carbohydrate Synthesis, Jiangxi Normal University, Nanchang 330022, P. R. China.
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23
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Hao F, Yokoyama S, Nishiwaki N. Direct dihalo-alkoxylation of nitroalkenes leading to β,β-dihalo-β-nitroethyl alkyl ethers. Org Biomol Chem 2018; 16:2768-2775. [PMID: 29611600 DOI: 10.1039/c8ob00408k] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A highly efficient one-pot synthesis of β,β-dihalo-β-nitroethyl alkyl ethers is achieved by the treatment of nitroalkenes with alcohols and N-halosuccinimides in the presence of sodium hydride. The notable advantages of this protocol are that it involves simple experimental manipulations and tolerates a wide range of functional groups. Further transformations of the obtained ethers, such as allylation and conversion to β,β-dihalogenated vinyl ethers, are also investigated.
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Affiliation(s)
- Feiyue Hao
- School of Environmental Science and Engineering, Kochi University of Technology, Tosayamada, Kami, Kochi 782-8502, Japan.
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24
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Visible light induced hydrodifluoromethylation of alkenes derived from oxindoles with (difluoromethyl)triphenylphosphonium bromide. J Fluor Chem 2018. [DOI: 10.1016/j.jfluchem.2018.01.013] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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25
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Moskowitz M, Balaraman K, Wolf C. Organocatalytic Stereoselective Synthesis of Fluorinated 3,3'-Linked Bisoxindoles. J Org Chem 2018; 83:1661-1666. [PMID: 29313686 PMCID: PMC5939997 DOI: 10.1021/acs.joc.7b03084] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A highly diastereoselective organocatalytic method that produces 3-fluoro-3'-hydroxy-3,3'-bisoxindoles and the corresponding 3-fluoro-3'-amino derivatives having two adjacent chirality centers from fluorooxindoles and isatins in high yields is described. The reaction occurs in protic solvents at room temperature, it can be upscaled without compromising yield and stereoselectivity, and chromatographic product purification is not required.
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Affiliation(s)
- Max Moskowitz
- Department of Chemistry, Georgetown University , 37th and O Streets, Washington, DC 20057, United States
| | - Kaluvu Balaraman
- Department of Chemistry, Georgetown University , 37th and O Streets, Washington, DC 20057, United States
| | - Christian Wolf
- Department of Chemistry, Georgetown University , 37th and O Streets, Washington, DC 20057, United States
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26
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Li X, Wei D, Li Z. Theoretical Study on DBU-Catalyzed Insertion of Isatins into Aryl Difluoronitromethyl Ketones: A Case for Predicting Chemoselectivity Using Electrophilic Parr Function. ACS OMEGA 2017; 2:7029-7038. [PMID: 31457285 PMCID: PMC6645149 DOI: 10.1021/acsomega.7b00907] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2017] [Accepted: 10/05/2017] [Indexed: 06/10/2023]
Abstract
The possible mechanisms of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU)-catalyzed chemoselective insertion of N-methyl isatin into aryl difluoronitromethyl ketone to synthesize 3,3-disubstituted and 2,2-disubstituted oxindoles have been studied in this work. As revealed by calculated results, the reaction occurs via two competing paths, including α and β carbonyl paths, and each path contains five steps, that is, nucleophilic addition of DBU to ketone, C-C bond cleavage affording difluoromethylnitrate anion and phenylcarbonyl-DBU cation, nucleophilic addition of difluoromethylnitrate anion to carbonyl carbon of N-methyl isatin, acyl transfer process, and dissociation of DBU and product. The computational results suggest that nucleophilic additions on different carbonyl carbons of N-methyl isatin via α and β carbonyl paths would lead to different products in the third step, and β carbonyl path associated with the main product 3,3-disubstituted oxindole is more energetically favorable, which is consistent with the experimental observations. Noteworthy, electrophilic Parr function can be successfully applied for exactly predicting the activity of reaction site and reasonably explaining the chemoselectivity. In addition, the distortion/interaction and noncovalent interaction analyses show that much more hydrogen bond interactions should be responsible for the lower energy of the transition state associated with β carbonyl path. The obtained insights would be valuable for the rational design of efficient organocatalysts for this kind of reactions with high selectivities.
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