1956-11-2Relevant articles and documents
FUNCTIONAL FLUOROCARBON MICELLES. PHASE SEPARATION AND REACTIVITY CHANGE OF HYDROXAMATE NUCLEOPHILES IN MIXED MICELLES OF HYDROCARBON AND FLUOROCARBON SURFACTANTS
Ihara, Hirotaka,Hashiguchi, Yuichi,Kunitake, Toyoki
, p. 733 - 736 (1983)
The titration behavior of long-chain(hydrocarbon and fluorocarbon) hydroxamic acids in the presence and absence of micellar matrices is influenced by phase separation of hydrocarbon and fluorocarbon species.The same factors operate in the hydrolysis of phenyl esters.
Efficient Assay for the Detection of Hydrogen Peroxide by Estimating Enzyme Promiscuous Activity in the Perhydrolysis Reaction
Wilk, Monika,Ostaszewski, Ryszard
, p. 1464 - 1469 (2021/02/01)
Hydrogen peroxide is an ideal oxidant in view of its availability, atom economy, or green aspects. Furthermore, it is produced by the cell mitochondria and plays a meaningful role in controlling physiological processes, but its unregulated production leads to the destruction of organs. Due to its diverse roles, a fast and selective method for hydrogen peroxide detection is the major limitation to preventing the negative effects caused by its excess. Therefore, we aimed to develop an efficient assay for the detection of H2O2. For this purpose, we combined the enzymatic method for the detection of hydrogen peroxide with the estimation of the promiscuity of various enzymes. We estimated the activity of an enzyme in the reaction of p-nitrophenyl esters with hydrogen peroxide resulting in the formation of peracid. To our knowledge, there is no example of a simple, multi-sensor demonstrating the promiscuous activity of an enzyme and detecting hydrogen peroxide in aqueous media.
A domino Kornblum-DeLaMare/aza-Michael reaction of 3,6-dihydro-1,2-dioxines and application to the synthesis of the ceramide transport inhibitor (±)-HPA-12
Legendre, Sarah V.A.-M.,Jevric, Martyn,Klepp, Julian,Sumby, Christopher J.,Greatrex, Ben W.
, p. 1229 - 1239 (2017/12/04)
A Kornblum-DeLaMare/aza-Michael reaction of 3,6-dihydro-1,2-dioxines with primary and secondary amines has been developed which affords 4-hydroxy-3-aminoketones. The aza-Michael products were reduced using non-selective NaBH4/MeOH or diastereoselective (up to 92:8) SnCl4/NaBH4 conditions yielding (1R?,3S?)-3-amino-1,4-diols in up to 97% and 70% yield respectively. The major reduction product was converted in two steps to (±)-HPA-12, which is an inhibitor of the cytosolic ceramide transporting protein.
Selective Decarbonylation of Fatty Acid Esters to Linear α-Olefins
John, Alex,Dereli, Büsra,Ortunìo, Manuel A.,Johnson, Hillis E.,Hillmyer, Marc A.,Cramer, Christopher J.,Tolman, William B.
, p. 2956 - 2964 (2017/08/21)
Selective decarbonylation of p-nitrophenol esters of fatty acids to the corresponding linear α-olefins (LAOs) was achieved using palladium catalysis. After extensive ligand screening, a mixed-ligand system exploiting the trans-spanning diphosphine XantPhos and an N-heterocyclic carbene (IPr) was identified as the most effective in yielding high α-selectivity and high conversions of the ester (>98% selectivity, >90% conversion using 2.5 mol % of PdCl2 and 5 mol % of the ligands, 190 °C, 2-2.5 h). On the basis of insights from modeling at the density functional level of theory, we propose that the mixed-ligand set achieves high α-selectivity by promoting olefin dissociation from the palladium center following β-hydride elimination, which is especially facilitated both by the combined steric bias of the mixed-ligand set and by the ability of the XantPhos ligand to coordinate in both mono- and bidentate fashions.
Dodecanoic acid derivatives: Synthesis, antimicrobial evaluation and development of one-target and multi-target QSAR models
Sarova, Devinder,Kapoor, Archana,Narang, Rakesh,Judge, Vikramjeet,Narasimhan, Balasubramanian
experimental part, p. 769 - 781 (2012/05/20)
In this study a series of dodecanoic acid derivatives (1-30) were synthesized and evaluated for in vitro antimicrobial activity against the panel of Gram positive, Gram negative bacterial and fungal strains. 4-Nitro phenyl dodecanoate (4) and quinolin-8-yl dodecanoate (5) emerged as most effective antibacterial agents, and 1-(4-benzylpiperazin- 1-yl) dodecan-1-one (15) was found to be the most effective antifungal agent amongst the synthesized dodecanoic acid derivatives. Quantitative structure activity relationship (QSAR) studies performed by the development of one-target and multi-target models indicated that multitarget model was effective in describing the antimicrobial activity of dodecanoic acid derivatives as well demonstrated the importance of topological parameter, zero-order molecular connectivity index (0X). Springer Science+Business Media, LLC 2010.
Catalytic, asymmetric Mannich-type reactions of N-acylimino esters: Reactivity, diastereo- and enantioselectivity, and application to synthesis of N-acylated amino acid derivatives
Kobayashi, Shu,Matsubara, Ryosuke,Nakamura, Yoshitaka,Kitagawa, Hidetoshi,Sugiura, Masaharu
, p. 2507 - 2515 (2007/10/03)
In the presence of a catalytic amount of Cu(OTf)2-chiral diamine 3e complex, N-acylimino esters reacted with silyl enol ethers to afford the corresponding Mannich-type adducts in high yields with high enantioselectivities. A wide variety of silyl enol ethers derived from ketones, as well as esters and thioesters, reacted smoothly. In the reactions of α-substituted silyl enol ethers (α-methyl or benzyloxy), the desired syn-adducts were obtained in high yields with high diastereo- and enantioselectivities. Several intermediates for the synthesis of biologically important compounds were prepared using this novel catalytic asymmetric Mannich-type reaction, and at the same time, absolute and relative stereochemical assignments were made. In addition, it has been revealed that alkyl vinyl ethers reacted with N-acylimino esters in the presence of a catalytic amount of the Cu(II) catalyst to give the corresponding Mannich-type adducts in high yields with high enantioselectivities. This is the first example of catalytic asymmetric Mannich-type reactions with alkyl vinyl ethers. The reaction mechanism, structure of chiral catalyst-electrophile complexes, and transition states of these catalytic asymmetric reactions were assumed based on X-ray crystallographic analysis of the Cu(II)-chiral amine complex, PM3 calculations, and FT-IR analyses, etc. Finally, (1R,3R)-N-(3-hydroxy- 1-hydroxymethyl-3-phenylpropyl)dodecanamide (HPA-12, 1), a new inhibitor of ceramide trafficking from endoplasmic reticulum to the site of sphingomyerin (SM) synthesis, has been synthesized efficiently using the present Mannich-type reaction as a key step. The synthesis involved three steps (two-pot), and total yield was 82.9%.
Metallomicelles as Catalysts of the Hydrolysis of Carboxylic and Phosphoric Acid Esters
Scrimin, Paolo,Tecilla, Paolo,Tonellato, Umberto
, p. 161 - 166 (2007/10/02)
Lipophilic ligands 2-4 have been synthesized.In the presence of Cu(II) ions, they form metallomicelles that are catalytically active in the cleavage of the p-nitrophenyl esters of acetic, hexanoic, and dodecanoic acids.Catalysis was also observed in the cleavage of p-nitrophenyl diphenyl phosphate.The apparent pKa of the Cu(II)-coordinated hydroxyl of ligand 2a, in the micellar aggregate, is 7.7, as estimated from the rate vs pH profiles for both classes of esters: this suggests that the hydroxyl is involved as a nucleophile in the hydrolytic cleavage, which proved to be a really catalytic process.The ligand bearing the free hydroxyl (2a) is more effective in the cleavage of carboxylate esters than ligands with the methylated alcoholic group (2b) or devoid of it (4); the opposite behaviour is observed in the cleavage of the phosphate triester.A rationale is offered that calls for the difference in the coordination ability to the metal center of phosphate and carboxylate esters.
HIGHER N-ACYL-L-AMINO ACID DERIVATIVES
Kochetkov, K. A.,Urmambetova, Zh. S.,Belikov, V. M.,Bakasova, Z. B.
, p. 2311 - 2316 (2007/10/02)
A preparative method is proposed for obtaining higher N-acylamino acids by reaction of free amino acids with fatty acid nitrophenyl esters.It was shown that these acids can transport positive ions through a liquid lipophilic medium.A direct method is proposed for obtaining fatty acid 4-nitrophenyl esters by boiling 4-nitrophenol and the fatty acid in xylene in a Soxhlet apparatus in the presence of an acid catalyst.
CHIMIE DES SUCRES SANS GROUPEMENTS PROTECTEURS-I-ESTERIFICATION REGIOSELECTIVE DE L'HYDROXYLE ANOMERE DU LACTOSE, DU MALTOSE ET DU GLUCOSE
Plusquellec, Daniel,Roulleau, Fabienne,Bertho, Francoise,Lefeuvre, Martine,Brown, Eric
, p. 2457 - 2468 (2007/10/02)
Treatment of acyl chlorides 4 with mercaptothiazoline, mercaptobenzothiazole, p-nitrophenol and 8-hydroxyquinoline in the presence of Et3N, afforded high yields of the corresponding reactive amides 5a-h,S-thioesters 6e-h and aryl esters 7e-h and 8a-h, respectively.The esters 6e-h, 7e-h and 8e-h reacted with excess β-lactose in pyridine, to give the corresponding β-esters 9e-h resulting from esterification of the anomeric hydroxyl of the sugar.The amides 5c, f-h gave the α-lactosyl esters 9c, f-h.The amide 5e and the esters 8b, c, e reacted with β-maltose, thus affording the corresponding β-maltosyl esters 10b, c, e, whereas the compounds 8a-e reacted with β-glucose, yielding the corresponding β-glucosyl esters 11a-e.This appears to be one of the very few selective chemical modifications of sugars known, which do not involve the toilsome protection-deprotection methology.The now commercially available maltosyl and glucosyl esters 10e and 11d-e are new non-ionic, and water soluble detergents which could be used for studies of cell membrane proteins.
the Effect of Hydrophobic-Lipophilic Interactions on Chemical Reactivity. 1. New Evidence for Intermolecular Aggregation and Self-Coiling
Jiang, Xi-Kui,Hui, Yong-Zheng,Fan, Wei-Qiang
, p. 3839 - 3843 (2007/10/02)
The hydrolytic behavior of 21 para-substituted phenyl esters of n-alkanoic acids (n-X) with various chain lengths in 60:40 (Φ=0.60), 50:50 (Φ=0.50), and 40:60 v/v (Φ=0.40) Me2SO-H2O mixtures was studied.Four new sets of experimental results which include departure from Hammett correlation for N-hexadecanoates (16-X), substantial differences in activation parameters, and effects of amylose on the kinetic parameters and on the activation parameters are presented along lines of reasoning mentioned by previous authors.These data establish that the aggregation and self-coiling of the n-alkanoate chain actually exist under experimental conditions.
