Abstract  We examine how the C-13 shafts of oligomers of branching polyesters made from glycerol or erythritol and the difunctional carboxylic acids malonic acid, succininc acid or glutaric acid reflect the location of the ester links on the alcohols, and whether these are influenced by a reaction of the acids at their second site. Assignments were made by observing the new shifts that appeared as the oligomers formed in reactions whose initial conditions were chosen to simplify the products; symmetry of structure was also used. Substitution parameters for each acid were obtained for each carbon in the alcohols, and found to be sensitive to whether the second function of the malonic and succinic acids had participated in ester formation. Cyclic products were discovered early in transesterification reactions of dimethyl malonate. For a fractal polyester a nomenclature is provided, an example prepared and characterized, and then shown to be modified by reactions: Fractal(G,S[-O-H]), fringed with hydroxyl groups, gave an acid-fringed fractal: Fractal(G,S[-CO-O-H]) (a hyperbranch of glycerol and succinate residues).

Abstract  Synthetic routes to potent bicyclic nonsteroidal sulfamate-based active-site-directed inhibitors of the enzyme steroid sulfatase (STS), an emerging target in the treatment of postmenopausal hormone-dependent diseases, including breast cancer, are described. Sulfamate analogs 9-27 and 28-46 of the core in vivo active two-ring coumarin template, modified at the 4- and 3-positions, respectively, were synthesized to expand structure-activity relationships. α-Alkylacetoacetates were used to synthesize coumarin sulfamate derivatives with 3-position modifications, and the bicyclic ring of other parent coumarins was primarily constructed via the Pechmann synthesis of hydroxyl coumarins. Compounds were examined for STS inhibition in intact MCF-7 breast cancer cells and in placental microsomes. Low nanomolar potency STS inhibitors were achieved, and some were found to inhibit the enzyme in MCF-7 cells ca. 100-500 more potently than the parent 4-methylcoumarin-7-O-sulfamate 3, with the best compounds close in potency to the tricyclic clinical drug Irosustat. 3-Hexyl-4-methylcoumarin-7-O-sulfamate 29 and 3-benzyl-4-methylcoumarin-7-O-sulfamate 41 were particularly effective inhibitors with IC50 values of 0.68 and 1 nM in intact MCF-7 cells and 8 and 32 nM for placental microsomal STS, respectively. They were docked into the STS active site for comparison with estrone 3-O-sulfamate and Irosustat, showing their sulfamate group close to the catalytic hydrated formylglycine residue and their pendant group lying between the hydrophobic sidechains of L103, F178, and F488. Such highly potent STS inhibitors expand the structure-activity relationship for these coumarin sulfamate-based agents that possess therapeutic potential and may be worthy of further development.

Abstract  Bulky, electron-rich phosphine ligands with a biphenyl backbone, when combined with Pd(OAc)(2), give highly active catalysts for the alpha-arylation of ketones. The ligand 2-methyl-2'-dicyclohexylphosphinobiphenyl is particularly effective, and with 0.1-1.0 mol % Pd, a large variety of aryl halides and ketones react efficiently and with high selectivity. For two types of substrates, the ligands BINAP and Xantphos are more effective than the biphenyl-based ligands. It is also shown that K3PO4 can be used as the base in these reactions, and that base-sensitive functional groups are better tolerated if this is used instead of NaO'Bu or NnHMDS. In some cases, alpha-aryl ketones can be produced without adding a ligand to the reaction. Although the substrate scope of the ligandless conditions is limited, some combinations react in high yield, and in one case, 100 000 turnovers were obtained. The results of experiments on the Pd-catalyzed arylation of diethyl malonate, cyclic 1,3-diketones, and nitroalkanes are also reported.

Abstract  Methods for enantioselective transfer of carbenes starting from precursors carrying two carbonyl groups have been elaborated. A one-pot procedure for olefin cyclopropanation with CH-acidic precursors via intermediate phenyliodonium ylides has been developed. The structure of the [Rh-2{(S)-nttl}4] catalyst was optimized to produce up to 98% ee in olefin cyclopropanations with dimethyl malonate or Meldrum's acid. Highly selective Rh(II)-catalyzed olefin cyclopropanations could be observed upon replacement of methyl diazoacetoacetate by methyl (silyloxyvinyl)diazoacetate. Enantioselective dipolar cycloadditions of diazopyruvate to polar olefins have been realized with Ru(II)-pybox catalysts.

Abstract  Treatment of (phenylsulfonyl)-1,2-propadiene (1) with bis(phenylsulfonyl)methane in the presence of sodium hydride affords 2,4,4-tris(phenylsulfonyl)-1-butene in 94% yield. Similar rearranged products were obtained using other soft nucleophiles and related allenes. The formation of these products involves addition of benzenesulfinate anion onto allene 1. The initially formed carbanion undergoes proton transfer with bis(phenylsulfonyl)methane followed by a S(N)2' reaction of the resulting anion with 2,3-bis(phenylsulfonyl)-1-propene. Supporting evidence for the proposed mechanism is provided by the observation that the reaction of dimethyl malonate with the activated allene in the presence of sodium benzenesulfinate gives mostly abnormal products. When allene 1 is allowed to react with olefins bearing an electron-withdrawing group in the presence of sodium benzenesulfinate, a substituted cyclopentenyl sulfone is formed. The reaction proceeds in a stepwise fashion by addition of the initially produced carbanion onto the activated pi-bond of the olefin followed by a 5-endo-trig cyclization and elimination of benzenesulfinate. This approach represents a mild and versatile anionic [3 + 2] route to five-membered unsaturated sulfones.

Abstract  A Pd/(R)-BINAP-catalyzed asymmetric benzylic substitution of secondary benzyl carbonates with amides and amines proceeds to form the corresponding optically active benzylamines in good yields with a high enantiomeric ratio. The reaction occurs in a dynamic kinetic asymmetric transformation (DYKAT) manner. Additionally, the asymmetric Pd catalysis can also be applicable to phenol nucleophiles, thus delivering chiral ethers with acceptable yields and enantioselectivity.

Abstract  In this study, biodegradable rigid cellular materials were synthesized from the reaction of malonic acid with epoxidized soybean oil. Malonic ester reacts with two epoxy reaction, initially formed malonic acid monoester (MAME) can decarboxylate and produce CO2, which acts as the blowing agent leading to in situ foaming of the polymer. Epoxide addition and decarboxylation reactions of MAME occur competitively and simultaneously and by controlling their relatives rates, foams of controlled density were produced. H-1 NMR spectrum of the synthesized foams showed that increasing the temperature increases the rate of decarboxylation reaction of MAME and decreases crosslink dencity leading to softer and lower density foams. Addition of 1,4-diazabicyclo[2.2.2]octane (DABCO) as a catalyst also increases the rate of decarboxylation. Load deflection curves of the cellular materials showed that decreasing the temperature and addition of DABCO increase compressive modulus of samples. Cell morphology was studied by microscopic images of foam samples that showed that foam samples have a closed cell structure and a wide distribution of cell volume. Soil burial test was done todetermine rate of biodegradation of foam samples. A half-life of 815 days showed that foam samples are highly biodegradable. (c) 2008 Wiley Periodicals, Inc.

Abstract  A series of chiral aminophosphine ligands with N,N-disubstituted 2-diphenylphosphinoaniline backbone are designed and readily prepared from (R)-2-(methoxymethyl)pyrrolidine or (S)-prolinol. The reactivity and selectivity in the palladium-catalyzed asymmetric allylic alkylation (AAA reaction) of 1, 3-diphenyl-2-propenyl acetate with a dimethyl malonate-BSA-LiOAc system using these chiral ligands are evaluated. Furthermore, chiral fluorous aminophosphine bearing two fluorous ponytails was prepared from (S)-prolinol. Chiral fluorous palladium catalyst from this ligand was easily reused in palladium-catalyzed AAA reaction with good enantioselectivity.

Abstract  The complexing capability of beta-diketone-3-substituted phthalides (isobenzofuranone) or isoindolinones toward Cu(II), Fe(III), Al(III), and Zn(II) salts has been highlighted by UV-vis spectroscopic studies. Conversely, heterocyclic analogs substituted with dimethyl malonate showed no complexing ability. Further insights have been given by the determination of equilibrium constants and distribution diagram, while the synthesis, isolation, and characterization of Cu(II)-beta-diketonate-isoindolinone complex has been achieved via a convenient modification of standard procedures. Moreover, in silico evaluation of bioavailability of the ligands is also discussed for potential pharmacological applications.

Abstract  Poly(vinylidene fluoride) (PVF2) produces thermoreversible gels in diesters. By variation of the number of intermittent carbon atoms (n = 0-7) of the diesters, the physical properties of the gels are studied. The morphology of the PVF2/diethyl oxalate (DEO) gel is spheroidal, but the morphology of PVF2-diethyl malonate (DEM) gel is a mixture of both spheroidal and fibrillar. The PVF2/diethyl succinate (DES), PVF2/diethyl gluterate (DEG), PVF2/diethyl pimelate (DEP), and PVF2/diethyl azelate (DEAZ) gels are "fibrillar-like" as evidenced from scanning electron microscopy (SEMI and transmission electron microscopy (TEM). The X-ray and solvent subtracted FT-IR spectra indicate the presence of a-polymorph PVF2 in all the gels. The enthalpy of gel formation and the enthalpy of gel fusion, measured from differential scanning calorimetry (DSC), show linear plot with PVF2 concentration for PVF2-DEO gels but others exhibit positive deviation from linearity. From the deviation vs PVF2 weight fraction (W-PVF2) plot, the compositions of the polymer solvent complexes are found to be 1:3, 1:2, 1:4, 1:4, and 1:3 in the molar ratio of the diester and PVF2 repeating unit, for gels in DEM, DES, DEG, DEP, and DEAZ, respectively. The phase diagrams of PVF2-DEM, PVF2-DES, and PVF2-DEP gels indicate polymer-solvent compound formation with a singular point while those of the PVF2-DEG and PVF2-DEAZ gels indicate compound formation with an incongruent melting point. The polymer solvent compound formation is also studied by molecular mechanics calculations using MMX program. The pairs of alpha-PVF2 and diester molecules with appropriate conformation to match the composition of the complex are energetically minimized. The distances between the >CF2 group and the carbonyl oxygen are lower than the summation of their van der Waals radii for all the diesters. The discrepancy between molecular modeling and morphology of the PVF2-DEO gels and the borderline morphology of PVF2-DEM gels have been explained from molecular mobility of the solvent and enthalpy of complexation (Delta H-c). The gel melting temperature and gelation temperature increases with increase in intermittent length (n) for a particular PVF2 concentration. Also, Delta H-c increases with "n", and this indicates that the intermittent length of diesters has both enthalpic and entropic contribution on gel behavior of PVF2.

Abstract  New iminophosphines have been synthesized from (R,R)-1-amino-2-diphenylphosphino cyclohexane (R.R)-1 in good to excellent yields. The catalysts obtained from iminophosphines 3a-g and [Pd(C3H5)Cl](2) promote the enantioselective allylic substitution of 1,3-diphenyl-2-propenyl acetate (6) with diethyl malonate with good enantioselectivity. The air-stable complex PdCl2[K-2-P,N-(R,R)-2-Ph2PC6H10N=CHPh] (4) has been prepared and structurally characterized by X-ray crystallography. (C) 2004 Elsevier B.V. All rights reserved.

Abstract  Three hydrometallurgical processes for industrial wastes treatment are presented. ?The main separation techniques are: solvent extraction, leaching-precipitation, electro-oxidation, and ion exchange. Recovery of gold from solid wastes generated in the electronic and jewellery industries consists of thermal degradation, two-stage leaching with nitric acid solution to remove silver and other metals and then with aqua regia to dissolve gold, selective solvent extraction of gold with diethyl malonate, and reduction of gold from the organic phase.

Vanadium recovery from residue ashes after burning heavy oil fractions consists of alkaline leaching of vanadium, filtration, neutralization of sodium vanadate solution, precipitation of ammonium metavanadate, drying of the precipitate, and adsorption of the remaining vanadium from the filtrate on an anionite. From the remaining ashes nickel is recovered using acidic leaching, filtration, precipitation of ammonium-nickelous sulphate, filtration, and drying.

The third process concerns processing of electroplating sludges and waste waters containing chromium and copper. The waste waters are electro-oxidized to transform Cr(III) into chromate. Then metal cations are separated on a cationite. The purified electroplating baths are recycled directly to electroplating; other solutions are first concentrated using anionite, followed by sodium chromate eluate conversion into concentrated chromic acid solution. The sludges accumulated from waste water processing by hydroxide precipitation are re-dissolved in chromic acid solution generated progressively by circulation between the dissolving and electro-oxidation steps. The concentrated chromic acid solution obtained is purified on the cationite and recycled.

Abstract  Using a malonic ester route, the first branched tandem intramolecular Diels-Alder (TIMDA) precursor, 3, was synthesized from sorbic acid in seven steps (15% overall yield). Treatment with Lewis acid catalysts (e.g., boron trifluoride etherate) affects the TIMDA reaction to afford a new fused-tetracyclic, 4, as two diastereomers (1:1). An alternative synthetic route to key intermediates used in the synthesis of linear TIMDA precursors has also been achieved.

Abstract  Tetracarboxylic acid ester was synthesized with diethyl malonate and methyl acrylate, and an amino terminated hyperbranched polymer (HBP-NH2) was prepared by reaction of a tetracarboxylic acid ester with diethylenetriamine (DETA). Hyperbranched polymer grafted chitosan (HBP-g-chitosan), a novel adsorbent material for Cr(VI) removal, was prepared from HBP-NH2 and chitosan with epichlorohydrin as crosslinking agent. The adsorbent was characterized by thermogravimetric analysis, Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray photoelectron spectrophotometry, and X-ray diffraction. The influence of the initial concentration of Cr(VI), the dosage of adsorbent, pH value and the coexisting anions on the adsorption performance were studied. An isotherm of the adsorption process was generated and studied by Langmuir and Freundlich models. The results showed that the Freundlich model proved to be more suitable than the Langmuir model. The adsorption kinetics were determined by pseudo-first order and pseudo-second order kinetics. In doing so, it was found that the pseudo-second order kinetic model was more reliable than the pseudo-first order kinetic model.

Abstract  A new and efficient method for the direct conversion of N-acyl oxazolidinones to a beta-keto ester is disclosed. The one-pot transformation is effected by the utilization of an excess of Lewis acid along with base and potassium ethyl malonate. This methodology has been applied to the large scale preparation of ethyl (R)-5-methyl-3-oxooetanoate. (c) 2008 Elsevier Ltd. All rights reserved.

Abstract  We describe a specific procedure for the synthesis of deuterium-labelled 2-(1-methylalkyl)succinate established via alkylation of diethyl malonate, Krapcho decarboxylation reaction with D2O and hydrolysis reaction. Two novel compounds, 2-[H-2]-2-ethylsuccinic acid and 2-(H-2-2-(1-methylheptyl)succinic acid were prepared via this synthetic route and characterized by mass spectrometry and H-1 NMR. The results showed that the 2-(1-methylalkyl)succinic acids were deuterated at the beta-position, which is considered as an important reaction centre in the anaerobic degradation of n-alkanes. (C) 2015 Chinese Chemical Society and Institute of Materia Medics, Chinese Academy of Medical Sciences. Published by Elsevier B.V. All rights reserved.

Abstract  Diffusion, permeation, and equilibrium sorption coefficients have been determined using a sorption gravimetric technique for methyl acetoacetate, ethyl acetoacetate, methyl benzoate, ethyl benzoate, methyl salicylate, isobutyl salicylate, and diethyl malonate into tetrafluoroethylene/propylene copolymer membranes in the temperature range 25-70 degrees C. The sorption kinetics process has been characterized by first-order rate constants and penetration velocities. From a temperature dependence of the transport coefficients, the activation parameters have been estimated. It is observed that the values of the transport coefficients for the systems of this study depend on the nature of the penetrant molecules rather than on their molecular sizes. On the whole, the mechanism of solvent transport into the copolymer membranes used here follows nearly the Fickian trend. (C) 1994 John Wiley and Sons, Inc.

Abstract  The reaction of barium or strontium metal in ammonia gas-saturated THF with two equivalents of dimethyl malonate (dmalH) in the presence of tetraethylene glycol dimethyl ether (tetraglyme) or 1,1,4,7,7-pentamethyldiethylenetriamine (pmdt) yields Ba(dmal)(2)(tetraglyme) (1), Ba(dmal)(2)(pmdt) (2). Sr(dmal)(2)(tetraglyme) (3). and Sr(dmal)(2)(pmdt) (4) as colorless crystals in reasonable yields (45-52%). These complexes have been characterized by spectroscopic methods (IR and H-1- and C-13-NMR) and elemental analysis data. Molecular structures of 1, 3, and 4 have been determined by X-ray diffraction studies and have revealed that they are monomeric and the tetraglyme or pmdt ligand wraps around a central metal atom in a meridional plane with the dmal ligands on opposite sides of this plane. (C) 2002 Elsevier Science B.V. All rights reserved.

Abstract  Fluorine smoothly attacks quinuclidine-trifluoroborane, quinuclidine-pentafluorophosphorane, and quinuclidine-sulfur trioxide in acetonitrile at -35 degrees C to give the corresponding N-fluoroquinuclidinium salts NFQ(+)X(-) (X(-)=BF4-, PF6-, and FSO3- respectively; Q = quinuclidine). Like its tetrafluoroborate analogue (NFQ(+)BF(4)(-)), the hexafluorophosphate NFQ(+)PF(6)(-) can also be prepared by direct fluorination of quinuclidine in the presence of the appropriate sodium salt (NaPF6). An alternative route to the tetrafluoroborate involves treatment of NFQ(+)F(-) with boron trifluoride. A comparative study of site-specific electrophilic fluorination of methoxybenzene [--> 1-fluoro-2- and 4-methoxybenzene], 2-hydroxynaphthalene (--> 1-fluoro-2-hydroxynaphthalene and 1,1-difluoro-2-oxo-1,2-dihydronaphthalene),2-nitropropan-2-yl-lithium (--> 2-fluoro-2-nitropropane) and diethyl sodio(phenyl) malonate [--> diethyl fluoro(phenyl) malonate] with all of the NFQ(+) X(-) salts mentioned above, plus the triflate (X(-) = CF3SO3-), revealed that the hexafluorophosphate and triflate are the most easily-handled and effective reagents.

Abstract  The complexing properties of four dimalonate and one diester calix[4]arene derivatives toward alkali and alkaline earth cations have been investigated in acetonitrile by means of UV spectrophotometry. Mononuclear complexes have been detected for all the complexes except in the case of ligands 4 and 5 with Na+ and Ca2+ where a biligand species (ML2) is present. This later stoichiometry was also confirmed by H-1-NMR and FAB(+) MS methods. In the case of ligand 3 and Sr2+ we observed the formation of both mono and binuclear species (ML, (ML)-L-2). Particular selectivities have to be noted from the unique complexation of Na+ and Ba2+ by ligand 2 and Rb+ by ligand 3 toward the two series of cations. The complexation is predominantly dependent on the bulkiness of the cavity and the cation size.

Abstract  The paper considers the possibility of increasing the sensitivity of semiconductor adsorption sensors using photon laser stimulation of low power. The results of experiments on the detection of vapors of malonic ester to semiconductor sensors manufactured on the basis of tin dioxide with various doping impurities with the use of laser irradiation and without it. The mechanism of photon stimulation was proposed and its effect was examined on the kinetics of adsorption and an increase the indicator effect.

Abstract  The bubble points for (triethyl orthoformate + diethyl malonate) at T = (373.15, 383.15, and 393.15) K and at p = 13.33 kPa, measured with an inclined ebulliometer are presented. The experimental results are analyzed using the UNIQUAC equation with the temperature-dependent binary parameters with satisfactory results. Experimental vapour pressures of triethyl orthoformate are also included. (C) 2004 Elsevier Ltd. All rights reserved.

Abstract  Novel P*-chiral P,N-bidentate ligands were synthesized by treatment of ferrocene-based imino alcohols with chlorophosphites derived from (S)-2-anilinomethylpyrrolidine or (S)-prolinol. Metal chelate complexes with the ligands [Rh(CO)(PN)Cl] and [Pd(PN)(allyl)]X-+(-) (X- = BF4-, Cl-, I-, CH12B11-) - were obtained and all new compounds were fully characterized by H-1, C-13, P-31 NMR, IR, MS (El, Cl, FAB, ESI and plasma desorption techniques) and X-ray analysis (imino alcohol 2d and complex 7). P*-Chiral diamidophosphites gave up to 97 % ee in the Pd-catalysed allylic substitution of 1,3-diphenylallyl acetate with dimethyl malonate and paratoluenesulfinate. ((c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)

Abstract  Ring-opening of N-(PhF)serine-derived cyclic sulfamidate 17 was achieved with different nucleophiles (beta -keto esters, beta-keto ketones, dimethyl malonate, nitroethane, sodium azide, imidazole, and potassium thiocyanate) to prepare a variety of amino acid analogs. Two different pathways for ring opening of 17 were elucidated: direct nucleophilic displacement, as well as beta -elimination followed by Michael addition. Furthermore, beta -keto ester and beta -keto ketone products 18k,18m, and 18i were converted to prolines and pyrazole amino acids.