- Light and oxygen-enabled sodium trifluoromethanesulfinate-mediated selective oxidation of C-H bonds
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Visible light-induced organic reactions are important chemical transformations in organic chemistry, and their efficiency highly depends on suitable photocatalysts. However, the commonly used photocatalysts are precious transition-metal complexes and elaborate organic dyes, which hamper large-scale production due to high cost. Here, for the first time, we report a novel strategy: light and oxygen-enabled sodium trifluoromethanesulfinate-mediated selective oxidation of C-H bonds, allowing high-value-added aromatic ketones and carboxylic acids to be easily prepared in high-to-excellent yields using readily available alkyl arenes, methyl arenes and aldehydes as materials. The mechanistic investigations showed that the treatment of inexpensive and readily available sodium trifluoromethanesulfinate with oxygen under irradiation of light could in situ form a pentacoordinate sulfide intermediate as an efficient photosensitizer. The method represents a highly efficient, economical and environmentally friendly strategy, and the light and oxygen-enabled sodium trifluoromethanesulfinate photocatalytic system represents a breakthrough in photochemistry. This journal is
- Fu, Hua,Liu, Can,Liu, Yong,Yang, Haijun,Zhu, Xianjin
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supporting information
p. 4357 - 4363
(2020/07/14)
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- HISTONE ACETYLTRANSFERASE ACTIVATORS AND COMPOSITIONS AND USES THEREOF
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The invention provides pharmaceutical compositions and methods for treating cancer, neurodegenerative disorders, conditions associated with accumulated amyloid-beta peptide deposits, Tau protein levels, and/or accumulations of alpha-synuclein by administering a HAT modulator and a HDAC modulator to a subject.
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Paragraph 0168-0169
(2018/02/21)
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- Uncatalyzed CO2Li-Mediated SNAr Reaction of Unprotected Benzoic Acids via Silicon Trickery
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The alkyl and aryllithium nucleophilic aromatic substitution (SNAr) displacement of a fluoro or methoxy group from unprotected 2-fluoro/methoxybenzoic acids is discussed. It was discovered that a TMS group located at the C6-position ortho to the carboxyl group shields effectively the carboxylate against nucleophilic attack, thus reducing dramatically ketone formation, and reorients nucleophilic substitution to the C2-position. The reactions with fluoro-substituted substrate 7 proceed efficiently; in contrast, the use of methoxy-functionalized benzoic acid 8 only affords moderate yields with s-BuLi and PhLi. This uncatalyzed coupling reaction, which provides a direct access to biaryl compounds, presumably proceeds by an addition-elimination sequence via intermediate formation of a resonance-stabilized pentavalent silalactone-Meisenheimer complex.
- Belaud-Rotureau, Mickael,Castanet, Anne-Sophie,Nguyen, Thi Huu,Mortier, Jacques
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p. 307 - 313
(2016/03/30)
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- HISTONE ACETYLTRANSFERASE ACTIVATORS AND USES THEREOF
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The invention provides compounds and compositions comprising compounds that modulate histone acyl transferase (HAT). The invention further provides methods for treating neurodegenerative disorders, conditions associated with accumulated amyloid-beta peptide deposits, Tau protein levels, and/or accumulations of alpha-synuclein as well as cancer by administering a compound that modulates HAT to a subject.
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Paragraph 00231-00235
(2015/11/02)
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- Zn-Catalyzed Enantio- and Diastereoselective Formal [4 + 2] Cycloaddition Involving Two Electron-Deficient Partners: Asymmetric Synthesis of Piperidines from 1-Azadienes and Nitro-Alkenes
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We report a catalytic asymmetric synthesis of piperidines through [4 + 2] cycloaddition of 1-azadienes and nitro-alkenes. The reaction uses earth abundant Zn as catalyst and is highly diastereo- and regioselective. A novel BOPA ligand (F-BOPA) confers high reactivity and enantioselectivity in the process. The presence of ortho substitution on the arenes adjacent to the bis(oxazolines) was found to be particularly impactful, due to limiting the undesired coordination of 1-azadiene to the Lewis acid and thus allowing the reaction to be carried out at lower temperature. A series of secondary kinetic isotope effect studies using a range of ligands implicates a stepwise mechanism for the transformation, involving an initial Michael-type addition of the imine to the nitro-alkene followed by a cyclization event. The stepwise mechanism obviates the electronic requirement inherent to a concerted mechanism, explaining the successful cycloaddition between two electron-deficient partners. (Chemical Equation Presented).
- Chu, John C. K.,Dalton, Derek M.,Rovis, Tomislav
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supporting information
p. 4445 - 4452
(2015/04/14)
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- Design and synthesis of selective and potent orally active S1P5 agonists
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Putting the brakes on demyelination: Fingolimod (FTY720) was recently shown to significantly decrease relapse rates in patients with multiple sclerosis. This drug attenuates the trafficking of harmful T-cells entering the brain by regulating sphingosine-1-phosphate (S1P) receptors. We designed, synthesized, evaluated 2H-phthalazin-1-one derivatives (e.g., 1L) as selective S1P5 receptor agonists; these compounds are highly potent and selective, with good PK properties, and significant activity in oligodendrocytes. (Chemical Presented).
- Mattes, Henri,Dev, Kumlesh Kumar,Bouhelal, Rochdi,Barske, Carmen,Gasparini, Fabrizio,Guerini, Danilo,Mir, Anis Khusro,Orain, David,Osinde, Maribel,Picard, Anne,Dubois, Celine,Tasdelen, Engin,Haessig, Samuel
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scheme or table
p. 1693 - 1696
(2012/01/02)
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- Synthesis of pyrrolnitrin and related halogenated phenylpyrroles
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A general approach to halogenated arylpyrroles, including the antifungal natural product pyrrolnitrin, is described using newly synthesized halogenated pyrroles and 2,6-disubstituted nitrobenzenes or 2,6-disubstituted anilines.
- Morrison, Matthew D.,Hanthorn, Jason J.,Pratt, Derek A.
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supporting information; experimental part
p. 1051 - 1054
(2009/07/18)
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- Halogen-metal exchange of 3-substituted 1,2-dibromoarenes: The use of long-range JCH coupling constants to determine regiochemistry
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Regioselective halogen/metal exchange reactions were carried out on a series of 3-substituted-1,2-dibromoarenes. Product mixtures were quenched with CO2 to form the corresponding benzoic acid analogs to facilitate HPLC and NMR analysis. Substitution at the 3-position could readily be assigned on the basis of 2D HMBC long-range correlations, while assignment at the 2-position was not as straightforward. The use of three-bond JCH coupling constant measurements, extracted from 1-D 1H coupled 13C experiments, were necessary to render unequivocal regio assignments. Copyright
- DiMichele, Lisa,Menzel, Karsten,Mills, Paul,Frantz, Doug,Nelson, Todd
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p. 1041 - 1043
(2008/02/05)
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- Regioselective halogen-metal exchange reaction of 3-substituted 1,2-dibromo arenes: The synthesis of 2-substituted 5-bromobenzoic acids
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Regioselective halogen-metal exchange reactions using isopropylmagnesium chloride were carried out on 3-substituted 1,2-dibromo arenes. Eleven examples are given. Georg Thieme Verlag Stuttgart.
- Menzel, Karsten,Dimichele, Lisa,Mills, Paul,Frantz, Doug E.,Nelson, Todd D.,Kress, Michael H.
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p. 1948 - 1952
(2008/02/08)
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- Promoting or preventing haloaryllithium isomerizations: Differential basicities and solvent effects as the crucial variables
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Deprotonation-triggered heavy halogen migrations should become a favorite tool in arene synthesis if their occurrence and outcome could be made predictable. Particularly attractive, though extremely rare, are stop-and-go situations where a first intermediate, generated by metalation, can be trapped at -100 °C, whereas at -75 °C halogen migration gives rise to an isomer. As shown now, one can conveniently produce the initial aryllithium species by halogen/metal interconversion in toluene at -100 °C, under conditions that preclude, halogen migration, and unleash the isomerization process by adding tetrahydrofuran at -75 °C.
- Heiss, Christophe,Rausis, Thierry,Schlosser, Manfred
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p. 617 - 621
(2007/10/03)
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- Regioselective ortho-lithiation of chloro and bromo substituted fluoroarenes
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Deprotonation of fluoroarenes carrying chlorine or bromine as additional substituents occurs always at a fluorine adjacent position if accomplished with potassium tert-butoxide activated butyllithium or lithium 2,2,6,6-tetramethylpiperidide.
- Mongin, Florence,Schlosser, Manfred
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p. 6551 - 6554
(2007/10/03)
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