10352-88-2Relevant academic research and scientific papers
Co-catalysis over a tri-functional ligand modified Pd-catalyst for hydroxycarbonylation of terminal alkynes towards α,β-unsaturated carboxylic acids
Yang, Da,Liu, Huan,Liu, Lei,Guo, Wen-Di,Lu, Yong,Liu, Ye
, p. 5336 - 5344 (2019)
An amphiphilic tri-functional ligand (L1) containing a Lewis acidic phosphonium cation, a phosphino-fragment and a hydrophilic sulfonate anion (-SO3-) enabled Pd(OAc)2 to efficiently co-catalyze the hydroxycarbonylation of terminal alkynes towards α,β-unsaturated carboxylic acids. These incorporated functional groups synergistically promoted the reaction, which proved more effective than the ligands lacking -SO3- and/or phosphonium and the mechanical mixtures of the individual functional groups independently. The molecular structure of Pd-L1 indicated that -SO3- in L1 served as a secondary O-donor ligand with reversible coordinating ability, cooperating with the phosphino-fragment to stabilize the Pd-catalyst. The in situ FT-IR analysis verified that the formation and stability of Pd-H active species in charge of hydroxycarbonylation were dramatically facilitated by the presence of L1. It was believed that, over the L1-based Pd-catalyst, H2O was cooperatively activated by the Lewis acidic phosphonium via "acid-base pair" interaction (H2O → P(v)+) and by the hydrophilic SO3-via hydrogen bonding (SO3-?H2O), giving rise to the formation of dimeric and mono-nuclear Pd-H species driven by reversible SO3--coordination. In addition, the L1-based Pd-catalyst could be immobilized in the ionic liquid [Bmim]NTf2 for six-run recycling uses without obvious activity loss and detectable metal leaching.
Inhibition of human cytochrome P450 2E1 and 2A6 by aldehydes: Structure and activity relationships
Kandagatla, Suneel K.,Mack, Todd,Simpson, Sean,Sollenberger, Jill,Helton, Eric,Raner, Gregory M.
, p. 195 - 202 (2014)
The purpose of this study was to probe active site structure and dynamics of human cytochrome P4502E1 and P4502A6 using a series of related short chain fatty aldehydes. Binding efficiency of the aldehydes was monitored via their ability to inhibit the binding and activation of the probe substrates p-nitrophenol (2E1) and coumarin (2A6). Oxidation of the aldehydes was observed in reactions with individually expressed 2E1, but not 2A6, suggesting alternate binding modes. For saturated aldehydes the optimum chain length for inhibition of 2E1 was 9 carbons (KI = 7.8 ± 0.3 μM), whereas for 2A6 heptanal was most potent (KI = 15.8 ± 1.1 μM). A double bond in the 2-position of the aldehyde significantly decreased the observed KI relative to the corresponding saturated compound in most cases. A clear difference in the effect of the double bond was observed between the two isoforms. With 2E1, the double bond appeared to remove steric constraints on aldehyde binding with KI values for the 5-12 carbon compounds ranging between 2.6 ± 0.1 μM and 12.8 ± 0.5 μM, whereas steric effects remained the dominant factor in the binding of the unsaturated aldehydes to 2A6 (observed KI values between 7.0 ± 0.5 μM and >1000 μM). The aldehyde function was essential for effective inhibition, as the corresponding carboxylic acids had very little effect on enzyme activity over the same range of concentrations, and branching at the 3-position of the aldehydes increased the corresponding KI value in all cases examined. The results suggest that a conjugated π-system may be a key structural determinant in the binding of these compounds to both enzymes, and may also be an important feature for the expansion of the active site volume in 2E1.
Direct reaction of dibromoacetic acid with aldehydes promoted by samarium diiodide: An easy, efficient, and rapid synthesis of (E)-α,β- unsaturated carboxylic acids with total stereoselectivity
Concellon, Jose M.,Concellon, Carmen
, p. 1728 - 1731 (2006)
A promoted SmI2 direct reaction of dibromoacetic acid with different aldehydes, followed by an elimination reaction also promoted by samarium diiodide, affords (E)-α,β-unsaturated carboxylic acids 2 with total stereoselectivity. A mechanism to explain this transformation is proposed.
Ligand-controlled divergent dehydrogenative reactions of carboxylic acids via C–H activation
Wang, Zhen,Hu, Liang,Chekshin, Nikita,Zhuang, Zhe,Qian, Shaoqun,Qiao, Jennifer X.,Yu, Jin-Quan
, p. 1281 - 1285 (2021/12/10)
Dehydrogenative transformations of alkyl chains to alkenes through methylene carbon-hydrogen (C–H) activation remain a substantial challenge. We report two classes of pyridine-pyridone ligands that enable divergent dehydrogenation reactions through palladium-catalyzed b-methylene C–H activation of carboxylic acids, leading to the direct syntheses of a,b-unsaturated carboxylic acids or g-alkylidene butenolides. The directed nature of this pair of reactions allows chemoselective dehydrogenation of carboxylic acids in the presence of other enolizable functionalities such as ketones, providing chemoselectivity that is not possible by means of existing carbonyl desaturation protocols. Product inhibition is overcome through ligand-promoted preferential activation of C(sp3)–H bonds rather than C(sp2)–H bonds or a sequence of dehydrogenation and vinyl C–H alkynylation. The dehydrogenation reaction is compatible with molecular oxygen as the terminal oxidant.
COMPOUNDS FOR USE AS AN ANTI-BACTERIAL OR ANTI-FUNGAL AGENT AND AS A ZINC SENSOR
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Paragraph 0107; 0108; 0109, (2018/01/18)
The present invention relates to a compound, which can be used as an anti-bacterial and/or an anti-fungal agent as well as a zinc sensor. Moreover, the present invention relates to a pharmaceutical composition comprising said compound and methods for treating bacterial or fungal infections in mammals.
MANUFACTURING METHOD OF α,β-UNSATURATED CARBOXYLIC ACID
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Paragraph 0050-0052, (2018/10/16)
PROBLEM TO BE SOLVED: To provide a manufacturing method which can get α,β-unsaturated carboxylic acid at a high yield by liquid phase oxidation of α,β-unsaturated aldehyde by oxygen or air with a handy metal catalyst under a mild reaction condition. SOLUTION: Preferably under a presence of organic solvent, α,β-unsaturated carboxylic acid is manufactured by oxidation of α,β-unsaturated aldehydes and oxygen or air under a presence of an iron salt catalyst and a catalyst of alkali metal salt of carboxylic acid. SELECTED DRAWING: None COPYRIGHT: (C)2017,JPOandINPIT
A lanthanide(III) triflate mediated macrolactonization/solid-phase synthesis approach for depsipeptide synthesis
Goodreid, Jordan D.,Dos Santos Da Silveira, Eduardo,Batey, Robert A.
supporting information, p. 2182 - 2185 (2015/05/13)
The effect of dysprosium(III) triflate on macrolactonization reactions to form depsipeptides using MNBA (Shiina's reagent) is reported. Improved yields were obtained for the formation of 16-membered depsipeptides using lanthanide triflate additives. The use of a macrocyclization strategy permits the use of a semiautomated solid-phase synthesis approach for the rapid synthesis of analogues of the antibacterial A54556 acyldepsipeptides in only two physical operations, requiring only final product purification after cyclization.
Preparation and odour properties of (S)-3-mercapto-1-heptyl acetate
Liang, Sen,Sun, Baoguo,Yang, Shaoxiang,Liu, Yongguo,Tian, Hongyu,Liu, Yuping,Chen, Haitao
, p. 343 - 346 (2014/07/08)
Synthesis of (S )-3-mercapto-1-heptyl acetate was achieved in four steps. Sharpless asymmetric epoxidation of (E )-2-heptenol yielded (2R,3R )-2,3-epoxy-1-heptanol, which was treated with thiourea in the presence of Ti(OPri)4 to give (2S,3S )-2,3-epithio- 1-heptanol, reduction of which followed by acetylation afforded (S )-3-mercapto-1-heptyl acetate in 91% ee. The optically active product possessed a tropical fruit aroma reminiscent of mango and passion fruit, with berry, ester-like, sweet, and pepper-like aspects.
General and efficient α-oxygenation of carbonyl compounds by TEMPO induced by single-electron-transfer oxidation of their enolates
Dinca, Emanuela,Hartmann, Philip,Smrcek, Jakub,Dix, Ina,Jones, Peter G.,Jahn, Ullrich
supporting information, p. 4461 - 4482 (2012/10/30)
A generally applicable method for the synthesis of protected α-oxygenated carbonyl compounds is reported. It is based on the single-electron-transfer oxidation of easily generated enolates to the corresponding α-carbonyl radicals. Coupling with the stable free radical TEMPO provides α-(piperidinyloxy) ketones, esters, amides, acids or nitriles in moderate-to-excellent yields. Enolate aggregates influence the outcome of the oxygenation reactions significantly. Competitive reactions have been analyzed and conditions for their minimization are presented. Chemoselective reduction of the products led to either N-O bond cleavage to α-hydroxy carbonyl compounds or reduction of the carbonyl functionality tomonoprotected 1,2-diols or O-protected amino alcohols. The oxygenation of enolates proves to be the most general and effective methodology for the synthesis of O-protected α-oxy carbonyl compounds and nitriles A. The scope and limitations of the electron-transfer-induced radical coupling reaction with TEMPO are presented. The reaction pathways are outlined. Methods for the deprotection to α-hydroxy carbonyl compounds B are provided and discussed. Copyright
Competitive formation of β-amino acids, propenoic, and ylidenemalonic acids by the Rodionov reaction from malonic acid, aldehydes, and ammonium acetate in alcoholic medium
Lebedev,Lebedeva,Sheludyakov,Kovaleva,Ustinova,Kozhevnikov
, p. 1113 - 1124 (2007/10/03)
The Rodionov reaction of 49 available aliphatic and aromatic aldehydes with malonic acid and ammonium acetate in alcoholic medium, resulting in formation of β-amino acids, propenoic, and ylidenemalonic acids, was studied. Certain regioselectivity regularities of the reaction were revealed. Among the variety of ketones studied, cyclohexanone is the only whose reaction yields a β-amino acid. Unusual dehydrofluorination of 6-chloro-2-fluorocinnamic acid under the Rodionov reaction was discovered. 2005 Pleiades Publishing, Inc.
