- Oncinotine-type spermidine alkaloids from Oncinotis tenuiloba. Transformation of N-acetyloncinotin-12-one to N,N-diacetylinandenin-12-one
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From extracts of Oncinotis tenuiloba STAPF, two novel polyamine alkaloids, oncinotin-11-one (5) and oncinotin-12-one (6), were isolated. Peracetylation of 6 provided the N-acetyl derivative 11 as well as N,N'-diacetylinandenin-10-en-12-one (12) due to a β-elimination-type side reaction resulting in ring enlargement of 11. Deuteration of 12 yielded 13, showing the same retention time as N,N'-diacetylinandenin-12-one (14), when co-HPLC was performed together with different keto-isomeric N,N'-diacetylinandeninones. Structure elucidation was extended by Schmidt degradation of 6 and N,N'-diacetyl(10,11-2H2)inandenin-12-one (13); the degradation products were identified by GC and ESI-MS. The structure of 5 was proposed on the basis of spectroscopic means. Comparison of the spectroscopic data of 5 with those obtained from synthetic material as well as co-HPLC of the N-acetyl derivative 20 together with the corresponding synthetic compound revealed the identity of the substances and confirmed the structure of 5. Additionally, oncinotine (2) and neooncinotine (3) were isolated, separated, and identified with authentic samples by co-HPLC of their N-acetyl derivatives 8 and 9, respectively.
- Doll,Guggisberg,Hesse
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- A new hypercrosslinked supermicroporous polymer, with scope for sulfonation, and its catalytic potential for the efficient synthesis of biodiesel at room temperature
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We have designed a new hypercrosslinked supermicroporous polymer (HMP-1) with a BET surface area of 913 m2 g-1 by FeCl3via a catalyzed Friedel-Crafts alkylation reaction between carbazole and α,α′-dibromo-p-xylene. Upon sulfonation HMP-1 yielded a very efficient solid acid catalyst for the production of biodiesels via esterification/transesterification of free fatty acids (FFA)/esters at room temperature.
- Bhunia, Subhajit,Banerjee, Biplab,Bhaumik, Asim
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- Mg/MeOH mediated intramolecular reductive cyclization of activated dienes
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Facile intramolecular cyclisation of activated tethered dienes mediated by magnesium in methanol at room temperature is described.
- Chavan, Subhash P.,Ethiraj, Krishna S.
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- Metal/bromide autoxidation of triglycerides for the preparation of FAMES to improve the cold-flow characteristics of biodiesel
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Triglyceride autoxidation using a homogeneous Co/Mn/Zr/bromide catalyst in acetic acid (93%) of low grade tallow, canola oil or soy bean oil in a batch reactor at 150 °C for 2 h, produced lower molecular weight products relative to the fatty acids of the starting triglycerides. For the autoxidation of tallow the main products after esterification were monoesters Me(CH 2)mC(O)OMe (m = 5-12) and diesters MeOC(O)(CH 2)nC(O)OMe, (n = 7-12). Oxidation of the saturated fatty acids in triglycerides was confirmed and modelled using methyl palmitate. Post-treatment esterification of tallow autoxidation products to produce biodiesel (BD) esters resulted in improved cold temperature properties by a mean of 13.0 °C, i.e. a mean cloud point (CP) 1.0 °C (cf. unmodified tallow biodiesel: CP 14 °C).
- Phung, Peter,Rowlands, William N.,Thiyakesan, Appadurai,Benndorf, Paul,Masters, Anthony F.,Maschmeyer, Thomas
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- Dinuclear metal complexes with saturated and unsaturated hydrocarbon bridges
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The reaction of the bis(triflates) [Y-(CH2)m-Y] [Y = F3CSO3, m = 4, 6-9, 12, 14, 16 (1a-h)] with the carbonyl metalates M′[M(CO)5] (M′ = Na, K; M = Mn, Re) affords the alkanediyl bridged metal complexes [(OC)5M-(CH2)m-M(CO)5] [m = 6-9, 12, 14, 16; M = Mn (2b-h) and m = 4, 6-9, 12, 14, 16; M = Re (3a-h)]. Starting with K[Mn(CO)5] and the bis(triflates) 1d and 1e the diesters [H3CO(O)C(CH2)mC(O)OCH3] [m = 8, 9 (4d,e)] are obtained in a one-pot reaction. The unsaturated hydrocarbon bridged rhenium complexes trans-[Re]-(CH2)2-CH=CH-(CH2)2-[Re] (6), cis-[Re]-(CH2)3-CH=CH-(CH2)3-[Re] (8), and [Re]-(CH2)p-CH2-C≡C-CH2-(CH2)p-[Re] {[Re] = Re(CO)5, p = 1, 3 (11, 12)} are formed by reaction of the bis(triflates) trans-Y-(CH2)2-CH=CH-(CH2)2-Y (5), cis-Y-(CH2)3-CH=CH-(CH2)3-Y (7), and Y-(CH2)p-CH2-C≡C-CH2-(CH2)p-Y [Y = F3CSO3, p = 1, 3 (9, 10)] with Na[Re(CO)5] in THF. The structure of 8 was determined by an X-ray structural analysis. Crystal data for 8: space group P21/n with a = 12.501(2), b = 6.592(2), c = 26.875(5)A, β = 93.28(2)°, V = 2211.0(9)A3, Z = 4. The structure was refined to R = 0.039, wR = 0.090.
- Lindner, Ekkehard,Leibfritz, Thomas,Fawzi, Riad,Steimann, Manfred
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- α-nitrocycloalkanones as a source of α,ω,-dicarboxylic acid dimethyl esters
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α,ω-Dicarboxylic acid dimethyl esters arc easily obtained by ring cleavage of α-nitrocycloalkanones. Thus, reaction of the latter compounds with three equivalents of potassium persulfate, in methanol and in presence of sulfuric acid at 80 °C, provides α,ω-dicarboxylic acid dimethyl esters in high yields. Long-chain, and alkylated α,ω-dicarboxylic acid dimethyl esters can be also efficiently obtained.
- Ballini, Roberto,Bosica, Giovanna
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- Synthesis of medium-chain carboxylic acids or α,ω-dicarboxylic acids from cellulose-derived platform chemicals
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Medium-chain fatty acids and their derivatives have important applications in the energy and chemical industries. Thus, we have prepared a series of medium-chain fatty acids by the selective hydrodeoxygenation of the aldol condensation products derived from cellulose using a metal triflate and Pd/C catalyst system. The selective retention of the carboxyl group is a notable feature of this catalytic system.
- Li, Xing-Long,Zhang, Kun,Jiang, Ju-Long,Zhu, Rui,Wu, Wei-Peng,Deng, Jin,Fu, Yao
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- A magnetically recoverable nanocatalyst based on functionalized mesoporous silica
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A magnetically separable 2D-hexagonally ordered thiol functionalized mesoporous silica material (Fe@TFMS) has been synthesized through co-condensation reaction of 3-mercaptopropyltriethoxysilane (MPTES) and tetraethylorthosilicate (TEOS) using cetyltrimethylammonium bromide (CTAB) as a cationic surfactant followed by immobilization of Fe3O4 nanocrystallies at the functionalized mesopore surface. Powder X-ray diffraction (XRD), N2 adsorption/desorption analysis, FT-IR, TEM, FE-SEM, TGA/DTA, CHNS, XPS and NH3-TPD tools are employed to characterize the materials. This functionalized mesoporous material exhibited high catalytic activity in the biodiesel production from a wide range of long chain fatty acids and soybean oil. The material showed high Lewis acidity of 1.02 mmolg-1 with a good Brunauer-Emmett-Teller (BET) surface area of 411 m2 g-1. Fe@TFMS exhibited excellent catalytic efficiency for this esterification reaction using methanol as a solvent cum reactant under eco-friendly and mild reaction conditions (room temperature, 25 °C).
- Bhanja, Piyali,Sen, Tapas,Bhaumik, Asim
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- Studies of Spin Labeled Sodium Dodecyl Sulfate. I. Synthesis and Properties
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Nitroxide spin labeled surfactant, sodium salt of 2-ethyl-2--4,4-dimethyloxazolidin-3-yloxyl, was synthesized and some properties of the compound were studied by means of ESR and conductivity measurements.From conductivity measurements it was found that the critical micelle concentration of the compound was 21.6 mmol kg-1 at 25.0 +/- 0.1 deg C and the micelle consisted of a small number of labeled surfactant ions.The ESR spectra of the labeled surfactant were measured as a function of concentration and temperature.These spectra showed a typical pattern interpreted in terms of spin exchange.Regarding spin exchange as chemical reaction, second order rate constant was determined from the analysis of line width and compared with the values obtained by diffusion controlled model.
- Yamaguchi, Takeo,Yamauchi, Akira,Kimoto, Eiji,Kimizuka, Hideo
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- On the search of new I2-IBS aliphatic ligands: Bis-guanidino carbonyl derivatives
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Continuing with our search of aliphatic dicationic derivatives as I2-IBS ligands and looking at Amiloride, a known ligand of I2-IBS, we have incorporated the guanidinocarbonyl moiety into our aliphatic compounds with the intention of improving the binding to I2-IBS. Thus, we present the different approaches to the preparation and pharmacological evaluation (in human brain tissue) as I2-IBS ligands of a new series of aliphatic derivatives incorporating the guanidinocarbonyl group and with different chain length (n = 8-12, and 14 methylene groups).
- Corcoran, Jonathan,Rodriguez, Fernando,Rozas, Isabel,Meana, J. Javier,Callado, Luis F.
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- NEW HYDROXY FATTY ACID FROM SEED OIL OF BALIOSPERMUM AXILLARE
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A fatty acid, found as a minor component in the seed oil of Baliospermum axillare, is shown to be the hitherto unknown 11,13-dihydroxytetracos-trans-9-enoic acid (axillarenic acid).Key Word Index - Baliospermum axillare; Euphorbiaceae; seed oil; 11,13-dihydroxytetracos-trans-9-enoic acid.
- Husain, Shahid,Ahmad, Moghis U.,Osman, S. M.
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- REGIO AND STEREO SELECTIVE SYNTHESIS OF DISUBSTITUTED CYCLOOCTADIENES.
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Functionalized dienes can be dimerized in the presence of Ni(o) catalyst in order to afford regio and stereo selectively 1,2-trans disubstituted 3,7-cyclooctadiene derivatives.
- Brun, P.,Tenaglia, A.,Waegell, B.
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- Self-assembled sulfated zirconia nanocrystals with mesoscopic void space synthesized via ionic liquid as a porogen and its catalytic activity for the synthesis of biodiesels
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Abstract Self-assembled ZrO2 nanocrystals have been synthesized through a facile chemical route via steam-assisted ionothermal method using 1-butyl-3-methylimidazolium chloride ([bmim][Cl]) as a porogen. The template-free material has been sulphonated by 1(N) H2SO4 at room temperature followed by calcination in air at 723 K. Both ZrO2 and the sulfonated zirconia materials are thoroughly characterized by powder X-ray diffraction (PXRD), ultra high-resolution transmission electron microscopy (UHR-TEM), Fourier transform infrared spectroscopy (FT-IR), FE-SEM, N2 sorption, and NH3-TPD analyses. The sulfonated material has been employed as efficient and environmentally benign heterogeneous catalyst for the synthesis of biodiesels based on long chain fatty acid esters. The catalyst can be easily recovered and reused at least for five times without significant decrease in its catalytic activity.
- Banerjee, Biplab,Bhunia, Subhajit,Bhaumik, Asim
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- One-pot ozonolytic synthesis of acyclic α,ω-bifunctional compounds from methyl 10-undecenoate and 10-undecen-1-ol
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Transformations of peroxy products formed by ozonolysis of undecylenic acid derivatives (methyl ester and hydride reduction product, 10-undecen-1-ol) in various protic and aprotic solvents (MeOH, Pr i OH, tetrahydrofuran, 1: 5 AcOH-CH2Cl2 mixture), occurring under the action of such reductants as hydroxylamine and semicarbazide hydrochlorides, were studied. These reductants exhibit high performance and in some cases high chemoselectivity, which allowed the development of a number of one-pot procedures for the synthesis of acyclic α,ω-bifunctional compounds, the majority of which are widely used in medicine, perfumery, cosmetics, engineering, and chemical industry, e.g., as block synthons in targeted organic synthesis.
- Legostaeva,Botsman,Nazarov,Yakovleva,Garifullina,Khalikov,Ishmuratov
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- Biomass-derived dibasic acids to diesters with inorganic ligand-supported catalyst: synthesis, optimization, characterization
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Several attempts have been made to obtain aliphatic dicarboxylic diesters from esterification reaction to develop the biomass-derived platform molecules and green manufacturing processes. In this paper, Na3(H2O)6[AlMo6O18(OH)6], an Anderson-type polyoxometalate, firstly, was reported as a catalyst for diester synthesis from dicarboxylic acid to diester which showed an well productivity and selectivity characterized by 1H and 13C. Response surface methodology (RSM) integrated with the desirability function approach was used to determine the best operative conditions, and the optimal reaction parameters for maximum dipropyl succinate yield (77 ± 2.5%) were identified as 1.19?mol.% catalyst loading, 4.9:1 propanol/succinic acid ratio, 113?°C, and 9.6?h. Three batches of tests were carried for catalyst recycling with 78–75% yield even after 6 cycles of esterification. In addition, the substrate carbon chain was increased for investigation of substrate scope achieving satisfactory results and all products were characterized by 1H and 13C nuclear magnetic resonance spectroscopy.
- Chen, Zhe,Han, Sheng,Lu, Deli,Xu, Yumeng
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- Synthesis and antiherpetic activity of novel purine conjugates with 7,8-difluoro-3-methyl-3,4-dihydro-2H-1,4-benzoxazine
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[Figure not available: see fulltext.] A method for the synthesis of novel purine conjugates with 7,8-difluoro-3-methyl-3,4-dihydro-2H-1,4-benzoxazine containing fragments of ω-amino acids with different lengths of the polymethylene chain as a linker has been developed. It was found in experiments in vitro that the obtained compounds are active against the herpes simplex virus type 1, including the acyclovir-resistant strain.
- Andronova, Valeriya L.,Charushin, Valery N.,Galegov, Georgii А.,Krasnov, Victor P.,Levit, Galina L.,Vozdvizhenskaya, Olga А.
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p. 490 - 497
(2021/06/26)
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- Efficient Palladium-Catalyzed Carbonylation of 1,3-Dienes: Selective Synthesis of Adipates and Other Aliphatic Diesters
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The dicarbonylation of 1,3-butadiene to adipic acid derivatives offers the potential for a more cost-efficient and environmentally benign industrial process. However, the complex reaction network of regioisomeric carbonylation and isomerization pathways, make a selective and direct transformation particularly difficult. Here, we report surprising solvent effects on this palladium-catalysed process in the presence of 1,2-bis-di-tert-butylphosphin-oxylene (dtbpx) ligands, which allow adipate diester formation from 1,3-butadiene, carbon monoxide, and methanol with 97 % selectivity and 100 % atom-economy under scalable conditions. Under optimal conditions a variety of di- and triesters from 1,2- and 1,3-dienes can be obtained in good to excellent yields.
- Yang, Ji,Liu, Jiawang,Ge, Yao,Huang, Weiheng,Ferretti, Francesco,Neumann, Helfried,Jiao, Haijun,Franke, Robert,Jackstell, Ralf,Beller, Matthias
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supporting information
p. 9527 - 9533
(2021/03/08)
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- Ruthenium-catalyzed hydrogenation of CO2as a route to methyl esters for use as biofuels or fine chemicals
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A novel robust diphosphine-ruthenium(ii) complex has been developed that can efficiently catalyze both the hydrogenation of CO2 to methanol and its in situ condensation with carboxylic acids to form methyl esters; a TON of up to 3260 is achievable for the CO2 to methanol step. Both aromatic and aliphatic carboxylic acids can be transformed to their corresponding methyl esters with high conversion and selectivity (17 aliphatic and 18 aromatic examples). On the basis of a series of experiments, a mechanism has been proposed to account for the various steps involved in the catalytic pathway. More importantly, this approach provides a promising route for using CO2 as a C1 source for the production of biofuels, fine chemicals and methanol.
- Li, Yong,Liu, Qingbin,Ma, Yanping,Solan, Gregory A.,Sun, Wen-Hua,Wang, Zheng,Zhang, Qiuyue,Zhao, Ziwei,Zhong, Yanxia
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p. 6766 - 6774
(2020/08/25)
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- PROCESS FOR PREPARING MONO AND DICARBOXYLIC ACIDS
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The present application relates to a process for preparing a dicarboxylic acid or dicarboxylic ester according to general formula (IV) R1OOC-(CH2)m-CH2CH2-(CH2)y-COOR4 (IV), comprising the steps of subjecting alkenoic acid or alkenoate of formula (II) R1OOC-(CH2)m-CH=CH-(CH2)x-H (II) to a metathesis reaction in the presence of a metathesis catalyst to form a longer-chain alkenoic acid or alkenoate of formula (III) R1OOC-(CH2)m-CH=CH-(CH2)y-H (III) where xa carbonylation reaction in the presence of a carbonylation catalyst and a carbonyl source to form said compound of Formula (IV). Alternative embodiments provide: a process for preparing an alkenoic acid or alkenoate comprising the step of subjecting a lactone to a ring opening reaction; a process for preparing a monocarboxylic acid or monocarboxylic ester according to general formula (XI) R1OOC-(CH2)m-CH2-(CH2)y-CH3 (XI) by subjecting an alkenoic acid or alkenoate to alkene hydrogenation; and a process for preparing an alcohol or ether according to general formula (XII) R1O-CH2-(CH2)m-CH2-(CH2)y-CH3 (XII) by subjecting an alkenoic acid or alkenoate to hydrogenation. The use of the respective mono/dicarboxylic acid, mono/dicarboxylic ester, ethers or alcohols in a variety of applications is also disclosed.
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- Methylation of mono- and dicarboxylic acids with dimethyl carbonate catalyzed with binder-free zeolite NaY
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Synthesis of methyl mono- and dicarboxylates was developed consisting in treating the corresponding acids with dimethyl carbonate in the presence of a heterogenic catalyst, crystalline aluminosilicate whose mechanically strong granules to 90–95% were built of crystal aggregates of zeolite Y with modulus of about 5.0 in the Na-form. Optimum catalyst and reagents ratio and the reaction conditions were found for the preparation in high yields of methyl esters of mono- and dicarboxylic acids.
- Khusnutdinov,Shchadneva,Mayakova, Yu. Yu.,Konovalova, Yu. S.,Khazipova,Kutepov
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p. 163 - 168
(2017/04/24)
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- Benzene-based diphosphine ligands for alkoxycarbonylation
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The invention relates to benzene-based diphosphine ligands for alkoxycarbonylation. Specifically, the invention relates to compounds of formula (I), where m and n are each independently 0 or 1; R1, R2, R3, R4 are each independently selected from -(C1-C12)-alkyl, -(C3-C12)-cycloalkyl, -(C3-C12)-heterocycloalkyl, -(C6-C20)-aryl, -(C3-C20)-heteroaryl; at least one of the R1, R2, R3, R4 radicals is a -(C3-C20)-heteroaryl radical; and to the use thereof as ligands in alkoxycarbonylation.
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Paragraph 0180; 0181; 0184
(2017/02/28)
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- The synthesis of di-carboxylate esters using continuous flow vortex fluidics
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A vortex fluidic device (VFD) is effective in mediating the synthesis of di-esters at room temperature. Processing under ambient conditions allows for a simple and efficient synthesis, whilst operating under continuous flow addresses scalability. The rotational speed of the sample tube and the flow rate were critical variables during reaction optimization, and this relates to the behaviour of the fluid flow at a molecular level. Whilst at specific rotational speeds the tube imparts a vibrational response into the fluid flow, the flow rate dictates residence time and the ability to maintain high levels of shear stress. The combination of mechanically induced vibrations, rapid micromixing, high levels of shear stress and water evaporation results in yields up to 90% for 3.25 minutes or less residence time. These results are key for devising greener and more efficient processes both mediated by the VFD and other continuous flow platforms.
- Britton, Joshua,Dalziel, Stuart B.,Raston, Colin L.
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p. 2193 - 2200
(2016/04/19)
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- Pd-Catalyzed Regioselective Alkoxycarbonylation of 1-Alkenes Using a Lewis Acid [SnCl2 or Ti(OiPr)4] and a Phosphine
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The phosphine ligand mediated palladium catalyzed alkoxycarbonylation of alkenes was investigated with the objective of attaining good linear selectivity for the ester. The effect of various parameters such as solvents, additives, palladium precursors, CO pressures, and alkenes of various structural complexities were examined. The results revealed the importance of using a Lewis acid such as SnCl2 or Ti(OiPr)4 in combination with a monodentate ligand such CYTOP 292 or P(p-anisyl)3 to enhance the regioselectivity for the linear isomers in the range of 70-96%.
- Amézquita-Valencia, Manuel,Achonduh, George,Alper, Howard
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p. 6419 - 6424
(2015/06/30)
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- Ozonolytic transformations of 10-undecenoic acid in various solvents through the action of hydroxylamine and semicarbazide hydrochlorides
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Ozonolytic transformations of 10-undecenoic acid, which is available from castor oil, were studied. Syntheses of several α,ω-bifunctional sebacic acid derivatives were developed.
- Ishmuratov,Legostaeva,Nasibullina,Garifullina,Botsman,Tolstikov
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p. 594 - 597
(2015/02/02)
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- METHOD FOR CONTINUOUSLY PREPARING CARBOXYLIC ACID ESTER
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A method for continuously preparing a carboxylic acid ester is disclosed. In the method of the present invention, a vertical reactor is filled with a solid catalyst, a carboxylic acid and an alcohol are introduced into a lower part of the vertical reactor, esterification is performed to form an esterized mixture, the esterized mixture is output from an upper part of the vertical reactor, and distillation is performed to isolate the carboxylic acid ester. The method of the present invention is simple, easily controlled and environmental friendly, and has significantly high conversion rate and selectivity.
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Paragraph 0030; 0034
(2013/11/19)
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- Organic-inorganic hybrid porous sulfonated zinc phosphonate material: Efficient catalyst for biodiesel synthesis at room temperature
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A new porous zinc phosphonate material (HZnP-1) has been synthesized via the reaction between p-xylenediphosphonic acid and anhydrous ZnCl2 under hydrothermal and mildly acidic conditions (pH ~ 5) in the absence of any structure directing agent. The phenyl group of this material has been sulfonated with concentrated sulfuric acid to obtain sulfonic acid functionalized material HZnPS-1. Powder X-ray diffraction (XRD), field emission scanning electron microscopy (FE SEM), N2 sorption, solid state 13C CP MAS and 31P MAS NMR, and FT IR spectroscopic tools are employed to characterize these materials. The crystal structures of both the materials are indexed corresponding to the new orthorhombic phases with unit cell parameters a = 11.00, b = 8.74, c = 14.62 A, α = β = γ = 90° for HZnP-1, and a = 10.65, b = 13.52, c = 15.30 A and α = β = γ = 90° for HZnPS-1. HZnPS-1 showed outstanding catalytic activity and high recycling efficiency for the synthesis of different biodiesel compounds via esterification of long chain fatty acids by using methanol as both reactant and solvent at room temperature. The green and eco-friendly catalytic system described herein can overcome the problem faced by the existing catalytic systems known in biodiesel synthesis, such as drastic conditions (high reaction temperature) and requirement of hazardous organic solvents.
- Pramanik, Malay,Nandi, Mahasweta,Uyama, Hiroshi,Bhaumik, Asim
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experimental part
p. 2273 - 2281
(2012/09/08)
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- Iridium-catalyzed oxidative methyl esterification of primary alcohols and diols with methanol
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Oxidative methyl esterification of primary alcohols and diols with methanol was successfully achieved, using acetone as a hydrogen acceptor, under the influence of an iridium complex combined with 2-(methylamino)ethanol (MAE) as catalyst.
- Yamamoto, Nobuyuki,Obora, Yasushi,Ishii, Yasutaka
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experimental part
p. 2937 - 2941
(2011/05/30)
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- Kolbe carbon-carbon coupling electrosynthesis using solid-supported bases
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(Chemical Equation Presented) We have developed a novel electrolytic system for Kolbe carbon-carbon coupling electrosynthesis based on the acid-base reaction between carboxylic acids as a substrate and solid-supported bases. On the basis of the electrolytic system, Kolbe electrolysis of various carboxylic acids was successfully carried out to provide the corresponding homocoupling products in moderate to excellent yields.
- Kurihara, Hitoshi,Fuchigami, Toshio,Tajima, Toshiki
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p. 6888 - 6890
(2008/12/22)
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- Ruthenium catalysed oxidation without CCl4 of oleic acid, other monoenic fatty acids and alkenes
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Ruthenium catalysed oxidation of alkenes and monoenic fatty acids is reported. The study of the influence of cosolvents (H2O/MeCN/X) shows that toxic CCl4 initially used in the Sharpless system (H 2O/MeCN/CCl4) can be avoided and demonstrates that the oxidative cleavage of CC bond could be accomplished in good yields with H 2O/MeCN/AcOEt solvent system in a ratio 3/2/2, respectively.
- Zimmermann, Fran?ois,Meux, Eric,Mieloszynski, Jean-Luc,Lecuire, Jean-Marie,Oget, Nicolas
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p. 3201 - 3203
(2007/10/03)
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- Identification and quantification of aerosol polar oxygenated compounds bearing carboxylic or hydroxyl groups. 1. Method development
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In this study, a new analytical technique was developed for the identification and quantification of multifunctional compounds containing simultaneously at least one hydroxyl or one carboxylic group, or both. This technique is based on derivatizing first the carboxylic group(s) of the multifunctional compound using an alcohol (e.g., methanol, 1-butanol) in the presence of a relatively strong Lewis acid (BF3) as a catalyst. This esterification reaction quicldy and quantitatively converts carboxylic acids to their ester forms. The second step is based on silylation of the ester compounds using bis(trimethylsilyl) trifluoroacetamide (BSTFA) as the derivatizing agent. For compounds bearing ketone groups in addition to carboxylic and hydroxyl groups, a third step was used based on PFBHA derivatization of the carbonyls. Different parameters including temperature, reaction time, and effect due to artifacts were optimized. A GC/MS in EI and in methane-CI mode was used for the analysis of these compounds. The new approach was tested on a number of multifunctional compounds. The interpretation of their EI (70 eV) and CI mass spectra shows that critical information is gained leading to unambiguous identification of unknown compounds. For example, when derivatized only with BF3-methanol, their mass spectra comprise primary ions at m/z M .+ + 1, M.+ + 29, and M.- - 31 for compounds bearing only carboxylic groups and M.- + 1, M.+ + 29, M.+ - 31, and M+. - 17 for those bearing hydroxyl and carboxylic groups. However, when a second derivatization (BSTFA) was used, compounds bearing hydroxyl and carboxylic groups simultaneously show, in addition to the ions observed before, ions at m/z M.+ + 73, M .+ - 15, M.+ - 59, M.+ - 75, M.+ - 89, and 73. To the best of our knowledge, this technique describes systematically for the first time a method for identifying multifunctional oxygenated compounds containing simultaneously one or more hydroxyl and carboxylic acid groups.
- Jaoui,Kleindienst,Lewandowski,Edney
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p. 4765 - 4778
(2007/10/03)
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- A mild and efficient method for esterification and transesterification catalyzed by iodine
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Iodine, was found to be a practical and useful Lewis acid catalyst for the esterification of carboxylic acids with alcohols. The high catalytic activity of iodine can be used for the transesterification of esters by different alcohols including tertiary alcohols and sterically hindered primary and secondary alcohols. The method presented is especially effective for simultaneous esterification and transesterification reactions.
- Ramalinga,Vijayalakshmi,Kaimal
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p. 879 - 882
(2007/10/03)
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- Mechanochemical Oxidation of Organic Model Compounds by Means of Potassium Permanganate
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Systematical investigation of solvent-free oxidations of organic model compounds with potassium permanganate on inorganic carriers leads to conclusion, that mechanochemical stimulation can induce oxidations. In case of the benzyl-type arenes these conversions are selective at good yields. Olefines react to carbonic acids. The presence of water enhances the yield of almost all educts.
- Nuechter, Matthias,Ondruschka, Bernd,Trotzki, Ronald
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p. 720 - 724
(2007/10/03)
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- Transformations of higher terpenoids: IV. Synthesis and spectral parameters of glycyrrhetinic acid derivatives containing amino acid fragments
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New glycyrrhetinic acid derivatives containing amino acid and amino ester fragments were synthesized as potential biologically active substances. NMR spectra of the newly synthesized compounds were studied, and assignment of signals of the C8 and C14 carbon atoms in the terpenoid fragment was refined.
- Petrenko,Petukhova,Shakirov,Shul'ts,Tolstikov
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p. 982 - 995
(2007/10/03)
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- 4-Quinolylmethyl and 1-naphthylmethyl as benzyl-type protecting groups of carboxylic acids removable by homogeneous palladium-catalyzed hydrogenolysis
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4-Quinolylmethyl (4-QUI) esters are reduced by palladium-catalyzed hydrogenolysis by formate anion. The reaction conditions are compatible with reducible substituents or functional groups as aromatic bromo, alkene, aldehyde, ketone, nitrile, ethyl and benzyl esters. An allyl ester is cleaved selectively in the presence of a 4-QUI ester. 1-Naphthylmethyl (1-NAP) esters of α-amino acids could be deprotected without any racemization by the same methodology. (C) 2000 Elsevier Science Ltd.
- Boutros, André,Legros, Jean-Yves,Fiaud, Jean-Claude
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p. 2239 - 2246
(2007/10/03)
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- Cosmetic and dermatological compositions containing a plasticizing oligomer and a film-forming polymer and uses thereof
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A composition comprising at least one film forming polymer and at least one oligomer chosen from homopolymers or copolymers of monomers containing ethylenic unsaturation and polycondensates, having an average molecular weight, measured at the peak height by steric exclusion chromatography, ranging from 400 to 10,000 and having a glass transition temperature ranging from -80 to 10° C., the composition containing no film-forming polymer of the nitrocellulose type is disclosed. Topical formulations formulated from this composition, in particular hair compositions for styling, holding and/or fixing the hair, and make-up compositions are also disclosed.
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- Synthesis and characterization of N,N'-aliphatic dicarboxylbis(hydrazones)
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N,N'-Malonylbis-, N,N'-adipinylbis- and N,N'-sebacoylbis(hydrazones) 1 of various aldehydes and ketones have been prepared and characterized by elemental analyses, melting points, and 1H NMR and IR spectral data.
- Amanulla, S.,Jain, S. R.
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p. 687 - 690
(2007/10/03)
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- Process for the preparation of bis(amidocarboxylic acids)
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A process is reported for the preparation of bis(amidocarboxylic acid) involving reacting an ester with an aminocarboxylate compound, the latter being formed from lactams or aminocarboxylic acids and salts thereof. The ester and aminocarboxylate compound are present in a weight ratio of about 1:1 to about 1:4, and reaction is conducted in a mono- or polyhydric alcohol solvent.
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- Cosmetic composition
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A composition suitable for topical application to mammalian skin or hair for inducing, maintaining or increasing hair growth comprises: (i) a first chemical inhibitor chosen from proteoglycanase inhibitors, glycosaminoglycanase inhibitors, glycosaminoglycan chain cellular uptake inhibitors or mixtures thereof; and (ii) a cosmetically acceptable vehicle for the chemical inhibitor; provided that when the first chemical inhibitor is a weak inhibitor, such that a 1 mM aqueous solution of the inhibitor reduces proteoglycanase activity, glycosaminoglycanase activity or cellular uptake of glycosaminoglycan chains, by from 5 to 50%, in accordance with at least one of the assay tests as herein described, then there is also present in the composition a second chemical inhibitor and/or an activity enhancer. When minoxidil is the sole chemical inhibitor, then the activity enhancer is a penetration enhancer chosen from a limited number of materials, including certain esters and cationic polymers. The total amount of chemical inhibitor present in the composition is sufficient to increase hair growth in the rat, when said composition is applied topically thereto, by at least 10% more than that obtainable using a control composition from which the said inhibitors have been omitted.
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- Dispiro-1,2,4-trioxolanes by Ozonolysis of Cycloalkylidenecycloalkanes on Polyethylene
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Ozonolyses of symmetrical (1b-d) and of unsymmetrical cycloalkylidenecycloalkanes (8a, b) afforded the dispiro-1,2,4-trioxolanes 4b-d and 9a, b, respectively.Their thermal decompositions gave mixtures of the cyclic ketones (3) and lactones (6).Photolysis afforded in addition to 3 and 6 the cyclic anhydrides 13, which are isomeric with the corresponding disoiro-1,2,4-trioxolanes.
- Griesbaum, Karl,Krieger-Beck, Petra,Beck, Johannes
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p. 391 - 396
(2007/10/02)
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- Selective Kolbe Electrolytic Coupling Using Glasslike-Hard Carbon Anodes
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The use of some kinds of glasslike-hard carbons was found to lead to selective synthesis of the corresponding Kolbe coupled products in high yields comparable to the use of a Pt anode in anodic oxidation of some carboxylic acids.
- Ohno, Toshinobu,Fukumoto, Tatsumi,Hirashima, Tsuneaki,Nishiguchi, Ikuzo
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p. 1085 - 1088
(2007/10/02)
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- Syntheses d'amidoesters par reaction de Kolbe
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The synthesis of amidoesters has been investigated by anodic cooxidation of diacid hemiesters CO2H-CH2-Z-CO2CH3 -CH2-> and amidoacids R1-N(Y)-(CH2)2-CO2H .The scope of this reaction was examined in detail.This synthetic pathway provided very a simple access to a wide range of amidoesters R1-N(Y)-(CH2)3-Z-CO2CH3 by varying Z and R1 as well as n value.
- Abderrahman, Ben Moufida,Laurent, Eliane,Marquet, Bernard
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p. 571 - 578
(2007/10/02)
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- THE INVENTION OF RADICAL REACTIONS. PART XV. SOME MECHANISTIC ASPECTS OF THE DECARBOXYLATIVE REARRANGEMENT OF THIOHYDROXAMIC ESTERS
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Esters (mixed anhydrides) derived from aliphatic or alicyclic carboxylic acids (RCO2H) and thiohydroxamic acids 2 or 3 undergo a thermally or photochemically induced radical chain reaction to give sulphides 4 with loss of carbon dioxide.On irradiation at low temperature however, the chain reaction is essentially suppressed.Under these conditions moderate to good yields of dimers R-R are obtained from primary acids.The mechanistic and synthetic implications of these observations are discussed.
- Barton, Derek H. R.,Bridon, Dominique,Fernandez-Picot, Isabel,Zard, Samir Z.
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p. 2733 - 2740
(2007/10/02)
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- Synthesis and Absolute Configuration of 2-Hydroxy-12-methyl Tridecanoic Acid
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The synthesis of racemic 2-hydroxy-12-methyl tridecanoic acid is described.The absolute configuration of the two enantiomers has been determined by the method of Dale and Mosher. - Keywords: 2-Hydroxy-12-methyl Tridecanoic Acid, Absolute COnfiguration
- Balzer, Th.,Budzikiewicz, H.
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p. 1367 - 1368
(2007/10/02)
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- Bifunctional compounds from reaction of alkoxy hydroperoxides with metal salts
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Alkoxy hydroperoxides, obtained by ozonizing olefins in alcoholic solution, were treated with ferrous sulfate. C-C bond scission and radical formation was followed by dimerization of the radicals formed. Ozonides reacted similarly. Acyclic and cyclic olefins, including a cyclic enol ether, gave rise to a range of α,ω-disubstituted products in modest yields. By using ferric chloride, ω-chloro esters were obtained from the alkoxy hydroperoxides derived from olefinic esters.
- Cardinale,Laan,Van Der Steen,Ward
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p. 6051 - 6054
(2007/10/02)
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- Metamorphosis of Castor Oil to Insect Sex-pheromones and Useful Synthons
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The primary fragmentation products of Castor oil (1), namely, methyl undec-10-enoate (2) and sebacic acid (3) have been converted, using novel reactions and strategies into synthons of the type H-CC-(CH2)n-3-CH2OTHP (n=6=4; n=7=14; n=8=22; n=9=29).A surprisingly clean decarboxylative elimination of sebacic acid monoester gives methyl non-8-enoate (7), a synthon related to recefeiolide and a precursor to 4, the utility of which, has been illustrated with the synthesis of insect-pheromones of the species Grapholita molesta.Methyl dec-9-enoate (15) has been prepared by a novel and practical terminal ? to lower terminal ? degradation of 2.Compound 7 has been transformed via synthon 14 to the insect sex-pheromones of the species, Spodoptera frugiperda, Heliothis virescens and Paralobesia viteana in high yields and excellent stereochemical purity. 1-Tetrahydropyranyloxyundec-10-yne (22) readily prepared from 2, has been used to illustrate a new strategy in pheromone synthesis, namely, the use of coupling elements, leading to the preparation of bombykol in high yields and excellent stereochemical purity. 1-Tetrahydropyranyloxydodec-11-yne (29), already reported, has been transformed to vaccenic acid (30), the transposed ?-isomer of oleic acid, in good yields, thus demonstrating the use of acetylide synthons for the preparation of rare fatty acids also.
- Ranganathan, S.,Maniktala, Vibha,Kumar, Raaj,Singh, G. P.
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p. 1197 - 1207
(2007/10/02)
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- The Synthesis of Specifically and Selectively Deuteriated 4,4'-Bisalkoxyazoxybenzene Derivatives
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In connection with deuterium n.m.r. studies of molecular motion in liquid crystals we have developed a number of methods for the synthesis of selectively deuteriated 4,4'-bisalkoxyazoxybenzenes.This paper is concerned with (i) the labelling of specific methylene segments of the alkoxy-chains, (ii) the labelling of the aromatic nucleus, and (iii) the selective enrichment of the deuterium content of one alkoxy-chain relative to the other.Our studies of the n.m.r. spectra of these liquid crystals have shown that there is not (as has sometimes been supposed) a monotonic decrease in C-D quadrupole splitting in passing from the oxygen to the CD3 end of the alkoxy-chain.In -PAA (p-azoxyanisole) we have also shown that the smaller splitting is associated with the CD3O group nearest to the NO end of azoxy-group.Whereas the photorearrangement of azoxy-compounds is normally regiospecific, the photorearrangement of PAA selectively deuteriated in one methoxy-group is unusual in that it leads to isotopically scrambled products.
- Boden, Neville,Bushby, Richard J.,Clark, Leslie D.
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p. 543 - 551
(2007/10/02)
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- LIGHT-INDUCED FREE-RADICAL REACTIONS OF 2-METHOXY-6-METHYLTETRAHYDROPYRAN: IRREVERSIBLE RING OPENING AND MULTISITE HYDROGEN ABSTRACTION
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Acetophenone-initiated photodegradation of cis-2-methoxy-4-methyltetrahydropyran (7) in benzene solvent produced six products.The structures of the products, and studies using optically active 7, showed that hydrogen abstraction occurs at both C-2 and C-6 of the tetrahydropyran ring.The products derived from the C-2 radical indicated two pathways for this radical: ring opening and loss of methyl, which is consistent with previous work on other similar systems.Results with optically active 7 showed that the ring-opening pathway is irreversible.Generation of an open-chain radical independently also showed that cyclization to a six membered ring does not occur.The products from the photodegradation were trans-2-methoxy-6-methyltetrahydropyran (8), methyl hexanoate (10), 6-methyltetrahydropyran-2-one (9), methyl 5-phenylhexanoate (11), 1,7-dimethyl-7-phenyl-6,8-dioxobicyclooctane (13), and 2-methoxy-2-(1-phenyl-1-hydroxyethyl)-6-methyltetrahydropyran (12).The yield of lactone 9 was found to be sensitive to the amount of residual oxygen present during the photolysis.
- Babcock, Bruce W.,Dimmel, Donald R.,Graves, David P.,McKelvey, Ronald D.
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p. 736 - 742
(2007/10/02)
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