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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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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3
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Zhang Y, Lai GW, Nie LJ, He Q, Lin MJ, Chi R, Lu DL, Fan X. Organocatalytic difluorobenzylation of 1,2-diketones via mild cleavage of carbon–carbon bonds. Org Chem Front 2022. [DOI: 10.1039/d1qo01645h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Difluoroacetophenones (DFAPs) are developed as a class of novel and practical reagents for organocatalytic difluorobenzylation reactions.
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Affiliation(s)
- Yong Zhang
- 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
| | - Long-Jun Nie
- Key Laboratory of Organo-Pharmaceutical Chemistry, Gannan Normal University, Ganzhou 341000, P. R. China
| | - Qifang He
- Key Laboratory of Organo-Pharmaceutical Chemistry, Gannan Normal University, Ganzhou 341000, P. R. China
| | - Mei-Juan Lin
- Key Laboratory of Organo-Pharmaceutical Chemistry, Gannan Normal University, Ganzhou 341000, P. R. China
| | - Rong Chi
- Key Laboratory of Organo-Pharmaceutical Chemistry, Gannan Normal University, Ganzhou 341000, P. R. China
| | - Dong-Liang Lu
- Key Laboratory of Organo-Pharmaceutical Chemistry, Gannan Normal University, Ganzhou 341000, P. R. China
| | - Xiaolin Fan
- Key Laboratory of Organo-Pharmaceutical Chemistry, Gannan Normal University, Ganzhou 341000, P. R. China
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4
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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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5
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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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6
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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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7
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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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8
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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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9
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Sadhukhan S, Santhi J, Baire B. The α,α‐Dihalocarbonyl Building Blocks: An Avenue for New Reaction Development in Organic Synthesis. Chemistry 2020; 26:7145-7175. [DOI: 10.1002/chem.201905475] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 01/08/2020] [Indexed: 01/04/2023]
Affiliation(s)
- Santu Sadhukhan
- Department of ChemistryIndian Institute of Technology Madras Chennai 600036 India
| | - Jampani Santhi
- Department of ChemistryIndian Institute of Technology Madras Chennai 600036 India
| | - Beeraiah Baire
- Department of ChemistryIndian Institute of Technology Madras Chennai 600036 India
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10
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Politanskaya LV, Selivanova GA, Panteleeva EV, Tretyakov EV, Platonov VE, Nikul’shin PV, Vinogradov AS, Zonov YV, Karpov VM, Mezhenkova TV, Vasilyev AV, Koldobskii AB, Shilova OS, Morozova SM, Burgart YV, Shchegolkov EV, Saloutin VI, Sokolov VB, Aksinenko AY, Nenajdenko VG, Moskalik MY, Astakhova VV, Shainyan BA, Tabolin AA, Ioffe SL, Muzalevskiy VM, Balenkova ES, Shastin AV, Tyutyunov AA, Boiko VE, Igumnov SM, Dilman AD, Adonin NY, Bardin VV, Masoud SM, Vorobyeva DV, Osipov SN, Nosova EV, Lipunova GN, Charushin VN, Prima DO, Makarov AG, Zibarev AV, Trofimov BA, Sobenina LN, Belyaeva KV, Sosnovskikh VY, Obydennov DL, Usachev SA. Organofluorine chemistry: promising growth areas and challenges. RUSSIAN CHEMICAL REVIEWS 2019. [DOI: 10.1070/rcr4871] [Citation(s) in RCA: 94] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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11
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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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12
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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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13
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Zhang L, Zhang W, Mei H, Han J, Soloshonok VA, Pan Y. Catalytic asymmetric aldol addition reactions of 3-fluoro-indolinone derived enolates. Org Biomol Chem 2018; 15:311-315. [PMID: 27910989 DOI: 10.1039/c6ob02454h] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Reported herein is a Cu(i)/bisoxazoline ligand-catalyzed aldol reaction of unprotected tertiary enolates generated in situ from 3-(1,1-dihydroxy-2,2,2-trifluoroethyl)-substituted derivatives of 3-fluoro-2-oxindoles. A range of α-fluoro-β-aryl/hetaryl/alkyl-β-hydroxy-indolin-2-ones containing C-F quaternary stereogenic centers of high pharmaceutical importance were furnished in good yields and satisfactory diastereo- and enantioselectivities. The reactions were conducted under operationally convenient conditions and displayed wide substrate/functional group generality including unprotected N-H on the tertiary enolates, and aromatic, hetero-aromatic and aliphatic aldehydes.
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Affiliation(s)
- Lijun Zhang
- School of Chemistry and Chemical Engineering, State Key laboratory of Coordination Chemistry, Nanjing University, Nanjing, 210093, China.
| | - Wenzhong Zhang
- School of Chemistry and Chemical Engineering, State Key laboratory of Coordination Chemistry, Nanjing University, Nanjing, 210093, China.
| | - Haibo Mei
- School of Chemistry and Chemical Engineering, State Key laboratory of Coordination Chemistry, Nanjing University, Nanjing, 210093, China.
| | - Jianlin Han
- School of Chemistry and Chemical Engineering, State Key laboratory of Coordination Chemistry, Nanjing University, Nanjing, 210093, China.
| | - Vadim A Soloshonok
- Department of Organic Chemistry I, Faculty of Chemistry, University of the Basque Country UPV/EHU, Paseo Manuel Lardizábal 3, 20018 San Sebastián, Spain. and IKERBASQUE, Basque Foundation for Science Department, Alameda Urquijo 36-5, Plaza Bizkaia, 48011 Bilbao, Spain
| | - Yi Pan
- School of Chemistry and Chemical Engineering, State Key laboratory of Coordination Chemistry, Nanjing University, Nanjing, 210093, China.
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14
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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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15
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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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16
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Zhang L, Zhang W, Sha W, Mei H, Han J, Soloshonok VA. Detrifluoroacetylative generation and chemistry of fluorine containing tertiary enolates. J Fluor Chem 2017. [DOI: 10.1016/j.jfluchem.2016.12.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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17
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Sha W, Zhang L, Wu X, Mei H, Han J, Soloshonok VA, Pan Y. Detrifluoroacetylative cascade reactions of bicyclic fluoro-enolates with ortho -phthalaldehyde: Aspects of reactivity, diastereo- and enantioselectivity. J Fluor Chem 2017. [DOI: 10.1016/j.jfluchem.2016.06.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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18
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Ding R, Bakhshi PR, Wolf C. Organocatalytic Insertion of Isatins into Aryl Difluoronitromethyl Ketones. J Org Chem 2017; 82:1273-1278. [PMID: 28032765 DOI: 10.1021/acs.joc.6b02704] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
An organocatalytic method that achieves insertion of isatins into aryl difluoronitromethyl ketones under mild conditions is described. The reaction occurs in the presence of 20 mol % of DBU and with 100% atom economy. A series of isatin derived difluoronitromethyl substituted tertiary alcohol benzoates and naphthoates were prepared in 81-99% yield. The general synthetic usefulness of these 3-hydroxyoxindole derivatives is demonstrated with the selective reduction to fluorooximes.
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Affiliation(s)
- Ransheng Ding
- Department of Chemistry, Georgetown University , Washington, DC 20057, United States
| | - Pegah R Bakhshi
- Department of Chemistry, Georgetown University , Washington, DC 20057, United States
| | - Christian Wolf
- Department of Chemistry, Georgetown University , Washington, DC 20057, United States
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19
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Xie C, Zhang L, Sha W, Soloshonok VA, Han J, Pan Y. Detrifluoroacetylative in Situ Generation of Free 3-Fluoroindolin-2-one-Derived Tertiary Enolates: Design, Synthesis, and Assessment of Reactivity toward Asymmetric Mannich Reactions. Org Lett 2016; 18:3270-3. [PMID: 27305459 DOI: 10.1021/acs.orglett.6b01516] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The discovery of detrifluoroacetylative in situ generation of a new type of fluorinated amide enolates derived from 3-fluoroindolin-2-one and their asymmetric Mannich additions with sulfinylaldimines bearing fluoroalkyl groups is reported, which afforded α-fluoro-β-(fluoroalkyl)-β-aminoindolin-2-ones containing C-F quaternary stereogenic centers with excellent yields and high diastereoselectivities.
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Affiliation(s)
- Chen Xie
- School of Chemistry and Chemical Engineering, State Key laboratory of Coordination Chemistry, Nanjing University , Nanjing 210093, China
| | - Lijun Zhang
- School of Chemistry and Chemical Engineering, State Key laboratory of Coordination Chemistry, Nanjing University , Nanjing 210093, China
| | - Wanxing Sha
- School of Chemistry and Chemical Engineering, State Key laboratory of Coordination Chemistry, Nanjing University , Nanjing 210093, China
| | - Vadim A Soloshonok
- Department of Organic Chemistry I, Faculty of Chemistry, University of the Basque Country UPV/EHU , Paseo Manuel Lardizábal 3, 20018 San Sebastián, Spain.,IKERBASQUE, Basque Foundation for Science, Alameda Urquijo 36-5, Plaza Bizkaia, 48011 Bilbao, Spain
| | - Jianlin Han
- School of Chemistry and Chemical Engineering, State Key laboratory of Coordination Chemistry, Nanjing University , Nanjing 210093, China
| | - Yi Pan
- School of Chemistry and Chemical Engineering, State Key laboratory of Coordination Chemistry, Nanjing University , Nanjing 210093, China
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