- Conversion of Arylboronic Acids into Potassium Aryltrifluoroborates: Convenient Precursors of Arylboron Difluoride Lewis Acids
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Reaction of ArB(OH)2 (3) with KHF2 affords crystalline salts KArBF3 (2).In the presence of TMSCl in acetonitrile, 2a reacts to give NMR signals typical of PhBF2 in acetonitrile solution.When the reaction of 2 + TMSCl is performed in the presence of potential Lewis bases, the trivalent borane 1 is intercepted, resulting in organoboron complexes.Thus, the oxazaborolidinones 7-10 have been prepared from amino acid-derived amidine carboxylates NaO2CCH(R)N=CHNMe2 (R = H or phenyl).Complexes 11 and 12 derived from 1,3-diketones are also easily prepared.The KHF2 fluoride exchange coupled with the TMSCl activation method allows in situ generation of ArBF2 without having to handle corrosive trivalent boron halides.
- Vedejs, E.,Chapman, R. W.,Fields, S. C.,Lin, S.,Schrimpf, M. R.
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- Catalytic, contra-Thermodynamic Positional Alkene Isomerization
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The positional isomerization of C═C double bonds is a powerful strategy for the interconversion of alkene regioisomers. However, existing methods provide access to thermodynamically more stable isomers from less stable starting materials. Here, we report
- Occhialini, Gino,Palani, Vignesh,Wendlandt, Alison E.
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supporting information
p. 145 - 152
(2022/01/19)
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- Silver-Catalysed Hydroarylation of Highly Substituted Styrenes
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Hydroarylation is an effective strategy to rapidly increase the complexity of organic structures by transforming flat alkene moieties into three-dimensional frameworks. Many strategies have already been developed to achieve the hydroarylation of styrenes,
- Dalton, Toryn,Gre?ies, Steffen,Das, Mowpriya,Niehues, Maximilian,Schrader, Malte L.,Gutheil, Christian,Ravoo, Bart Jan,Glorius, Frank
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supporting information
p. 8537 - 8541
(2021/03/16)
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- Electrochemical Vicinal Difluorination of Alkenes: Scalable and Amenable to Electron-Rich Substrates
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Fluorinated alkyl groups are important motifs in bioactive compounds, positively influencing pharmacokinetics, potency and conformation. The oxidative difluorination of alkenes represents an important strategy for their preparation, yet current methods are limited in their alkene-types and tolerance of electron-rich, readily oxidized functionalities, as well as in their safety and scalability. Herein, we report a method for the difluorination of a number of unactivated alkene-types that is tolerant of electron-rich functionality, giving products that are otherwise unattainable. Key to success is the electrochemical generation of a hypervalent iodine mediator using an “ex-cell” approach, which avoids oxidative substrate decomposition. The more sustainable conditions give good to excellent yields in up to decagram scales.
- Doobary, Sayad,Sedikides, Alexi T.,Caldora, Henry P.,Poole, Darren L.,Lennox, Alastair J. J.
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supporting information
p. 1155 - 1160
(2019/12/11)
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- Cross-coupling synthesis of methylallyl alkenes: Scope extension and mechanistic study
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Cross-coupling reactions between 2-methyl-2-propen-1-ol and various boronic acids are used to obtain aromatic-(2-methylallyl) derivatives. However, deboronation or isomerization side reactions may occur for several boronic acids. We describe herein the synthesis of original alkenes with good yields under mild reaction conditions that decrease these side reactions. The scope of this environmentally benign reaction is thereby extended to a wide variety of boronic acids. A mechanistic study was conducted and suggested a plausible catalytic cycle mechanism, pointing to the importance of the Lewis acidity of the boronic acid used.
- Tabélé, Clémence,Curti, Christophe,Kabri, Youssef,Primas, Nicolas,Vanelle, Patrice
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p. 22890 - 22899
(2016/01/25)
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- Palladium-catalyzed C(sp2) - H cyanation using tertiary amine derived isocyanide as a cyano source
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An unprecedented palladium-catalyzed cyanation of aromatic C-H bonds by using tertiary amine derived isocyanide as a novel cyano source was developed. Cu(TFA)2 was used as a requisite stoichiometric oxidant. Mechanistic studies suggest that a tertiary carbon cation-based intermediate is involved following the C-N bond breakage.
- Peng, Jiangling,Zhao, Jiaji,Hu, Ziwei,Liang, Dongdong,Huang, Jinbo,Zhu, Qiang
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p. 4966 - 4969,4
(2012/12/12)
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- GAMMA SECRETASE MODULATORS
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In its many embodiments, the present invention provides a novel class of heterocyclic compounds of the formula: as modulators of gamma secretase, methods of preparing such compounds, pharmaceutical compositions containing one or more such compounds, methods of preparing pharmaceutical formulations comprising one or more such compounds, and methods of treatment, prevention, inhibition, or amelioration of one or more diseases associated with the central nervous system using such compounds or pharmaceutical compositions.
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Page/Page column 341
(2010/06/15)
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