- Hydrogenation of olefins in supercritical CO2 catalyzed by palladium nanoparticles in a water-in-CO2 microemulsion
-
Nanometer-sized metallic palladium particles can be synthesized by hydrogen reduction of Pd2+ ions dissolved in the water core of a water-in-CO2 microemulsion. The Pd nanoparticles, stabilized by the micromeulsion and uniformly dispersed in the supercritical fluid phase, are effective catalysts for hydrogenation of olefins. Examples of rapid and efficient hydrogenation of water-soluble and CO2-soluble olefins catalyzed by the Pd nanoparticles in supercritical CO2 are given. Copyright
- Ohde, Hiroyuki,Wai, Chien M.,Kim, Hakwon,Kim, Jeongryul,Ohde, Mariko
-
-
Read Online
- Kinetics-Driven Drug Design Strategy for Next-Generation Acetylcholinesterase Inhibitors to Clinical Candidate
-
The acetylcholinesterase (AChE) inhibitors remain key therapeutic drugs for the treatment of Alzheimer's disease (AD). However, the low-safety window limits their maximum therapeutic benefits. Here, a novel kinetics-driven drug design strategy was employed to discover new-generation AChE inhibitors that possess a longer drug-target residence time and exhibit a larger safety window. After detailed investigations, compound 12 was identified as a highly potent, highly selective, orally bioavailable, and brain preferentially distributed AChE inhibitor. Moreover, it significantly ameliorated cognitive impairments in different mouse models with a lower effective dose than donepezil. The X-ray structure of the cocrystal complex provided a precise binding mode between 12 and AChE. Besides, the data from the phase I trials demonstrated that 12 had good safety, tolerance, and pharmacokinetic profiles at all preset doses in healthy volunteers, providing a solid basis for its further investigation in phase II trials for the treatment of AD.
- Zhou, Yu,Fu, Yan,Yin, Wanchao,Li, Jian,Wang, Wei,Bai, Fang,Xu, Shengtao,Gong, Qi,Peng, Tao,Hong, Yu,Zhang, Dong,Zhang, Dan,Liu, Qiufeng,Xu, Yechun,Xu, H. Eric,Zhang, Haiyan,Jiang, Hualiang,Liu, Hong
-
p. 1844 - 1855
(2021/03/01)
-
- Photoredox Activation of Formate Salts: Hydrocarboxylation of Alkenes via Carboxyl Group Transfer
-
A photoredox activation mode of formate salts for carboxylation was developed. Using a formate salt as the reductant, carbonyl source, and hydrogen atom transfer reagent, a wide range of alkenes can be converted into acid products via a carboxyl group tra
- Huang, Yan,Hou, Jing,Zhan, Le-Wu,Zhang, Qian,Tang, Wan-Ying,Li, Bin-Dong
-
p. 15004 - 15012
(2021/12/14)
-
- Photoinduced Hydrocarboxylation via Thiol-Catalyzed Delivery of Formate across Activated Alkenes
-
Herein we disclose a new photochemical process to prepare carboxylic acids from formate salts and alkenes. This redox-neutral hydrocarboxylation proceeds in high yields across diverse functionalized alkene substrates with excellent regioselectivity. This operationally simple procedure can be readily scaled in batch at low photocatalyst loading (0.01% photocatalyst). Furthermore, this new reaction can leverage commercially available formate carbon isotologues to enable the direct synthesis of isotopically labeled carboxylic acids. Mechanistic studies support the working model involving a thiol-catalyzed radical chain process wherein the atoms from formate are delivered across the alkene substrate via CO2?- as a key reactive intermediate.
- Alektiar, Sara N.,Wickens, Zachary K.
-
supporting information
p. 13022 - 13028
(2021/09/03)
-
- Synthesis, crystal structure, and catalytic activity of bridged-bis(N-heterocyclic carbene) palladium(II) complexes in selective Mizoroki-Heck cross-coupling reactions
-
A series of three 1,3-propanediyl bridged bis(N-heterocyclic carbene)palladium(II) complexes (Pd-BNH1, Pd-BNH2, and Pd-BNH3), with + I effect order of the N-substituents of the ligand (isopropyl > benzyl > methoxyphenyl), was the subject of a spectroscopic, structural, computational and catalytic investigation. The bis(NHC)PdBr2 complexes were evaluated in Mizoroki-Heck coupling reactions of aryl bromides with styrene or acrylate derivatives and showed high catalytic efficiency to produce diarylethenes and cinnamic acid derivatives. The X-ray structure of the most active palladium complex Pd-BNH3 shows that the Pd(II) center is bonded to the two carbon atoms of the bis(N-heterocyclic carbene) and two bromide ligands in cis position, resulting in a distorted square planar geometry. The NMR data of Pd-BNH3 are consistent with a single chair-boat rigid conformer in solution with no dynamic behavior of the 8-membered ring palladacycle in the temperature range 25–120 °C. The catalytic activities of three Pd-bridged bis(NHC) complexes in the Mizoroki-Heck cross-coupling reactions were not found to have a direct correlation with +I effect order of the N-substituents of the ligand. However, a direct correlation was found between the DFT calculated absolute softness of the three complexes with their respective catalytic activity. The highest calculated softness, in the case of Pd-BNH3, is expected to favor the coordination steps of both the soft aryl bromides and alkenes in the Heck catalytic cycle.
- El Ali, Bassam,Fettouhi, Mohammed,Iali, Wissam,Mansour, Waseem,Suleiman, Rami
-
-
- Synthetic and Mechanistic Studies on 2,3-Dihydrobenzo[ b ][1,4]-oxaselenines Formation from Selenocyanates
-
An expedient preparation of selenium-containing hetero-cycles via an m -chloroperbenzoic acid-mediated seleno-annulation starting from selenocyanate derivatives is described. In spite of its significance, this cyclization reaction is virtually understudied not only from the point of view of its scope, but also from the mechanistic aspects associated to this remarkable transformation. In this sense, several selenocyanate and thiocyanate derivatives bearing an aromatic ring were evaluated as substrates under different reaction conditions of this interesting cyclization yielding important insights on its scope as well as relevant information on the reaction mechanism.
- Bonesi, Sergio M.,Cattaneo, Mauricio,Chao, María N.,Rodriguez, Juan B.,Sanchez Gonzalez, Jonathan,Szajnman, Sergio H.
-
p. 1643 - 1658
(2020/05/25)
-
- Generalized Chemoselective Transfer Hydrogenation/Hydrodeuteration
-
A generalized, simple and efficient transfer hydrogenation of unsaturated bonds has been developed using HBPin and various proton reagents as hydrogen sources. The substrates, including alkenes, alkynes, aromatic heterocycles, aldehydes, ketones, imines, azo, nitro, epoxy and nitrile compounds, are all applied to this catalytic system. Various groups, which cannot survive under the Pd/C/H2 combination, are tolerated. The activity of the reactants was studied and the trends are as follows: styrene'diphenylmethanimine'benzaldehyde'azobenzene'nitrobenzene'quinoline'acetophenone'benzonitrile. Substrates bearing two or more different unsaturated bonds were also investigated and transfer hydrogenation occurred with excellent chemoselectivity. Nano-palladium catalyst in situ generated from Pd(OAc)2 and HBPin extremely improved the TH efficiency. Furthermore, chemoselective anti-Markovnikov hydrodeuteration of terminal aromatic olefins was achieved using D2O and HBPin via in situ HD generation and discrimination. (Figure presented.).
- Wang, Yong,Cao, Xinyi,Zhao, Leyao,Pi, Chao,Ji, Jingfei,Cui, Xiuling,Wu, Yangjie
-
supporting information
p. 4119 - 4129
(2020/08/10)
-
- Harnessing Applied Potential: Selective β-Hydrocarboxylation of Substituted Olefins
-
The construction of carboxylic acid compounds in a selective fashion from low value materials such as alkenes remains a long-standing challenge to synthetic chemists. In particular, β-addition to styrenes is underdeveloped. Herein we report a new electrosynthetic approach to the selective hydrocarboxylation of alkenes that overcomes the limitations of current transition metal and photochemical approaches. The reported method allows unprecedented direct access to carboxylic acids derived from β,β-trisubstituted alkenes, in a highly regioselective manner.
- Alkayal, Anas,Buckley, Benjamin R.,Malkov, Andrei V.,Montanaro, Stephanie,Tabas, Volodymyr,Wright, Iain A.
-
supporting information
(2020/02/13)
-
- Exploration of New Biomass-Derived Solvents: Application to Carboxylation Reactions
-
A range of hitherto unexplored biomass-derived chemicals have been evaluated as new sustainable solvents for a large variety of CO2-based carboxylation reactions. Known biomass-derived solvents (biosolvents) are also included in the study and the results are compared with commonly used solvents for the reactions. Biosolvents can be efficiently applied in a variety of carboxylation reactions, such as Cu-catalyzed carboxylation of organoboranes and organoboronates, metal-catalyzed hydrocarboxylation, borocarboxylation, and other related reactions. For many of these reactions, the use of biosolvents provides comparable or better yields than the commonly used solvents. The best biosolvents identified are the so far unexplored candidates isosorbide dimethyl ether, acetaldehyde diethyl acetal, rose oxide, and eucalyptol, alongside the known biosolvent 2-methyltetrahydrofuran. This strategy was used for the synthesis of the commercial drugs Fenoprofen and Flurbiprofen.
- Gevorgyan, Ashot,Hopmann, Kathrin H.,Bayer, Annette
-
p. 2080 - 2088
(2020/02/20)
-
- Synthesis method of succinic acid derivative or 3 -arylpropionic acid (by machine translation)
-
The invention discloses a synthesis method of a succinic acid derivative or 3 -arylpropionic acid, which comprises the following steps: adding a base in a drying reaction tube and CO removing CO. 2 The reaction is carried out under the irradiation of visible light, the reaction is carried out under visible light irradiation, and then separation and purification are carried out to obtain the butanedioic acid derivative or 3 -arylpropionic acid product; the base comprises sodium tert-butoxide, potassium tert-butoxide, lithium tert-butyl alcohol and 4 - potassium carbonate; and the reaction substrate comprises an acrylate compound or an aryl vinyl compound. CO can be induced by visible light. 2 The scheme provided by the invention is mild in reaction condition and wide in reaction 3 - substrate selectivity, and the reaction substrate is wide in selectivity, the raw materials are cheap and easily available, and the method has a good industrial application prospect. (by machine translation)
- -
-
Paragraph 0101-0114; 0115; 0121
(2020/10/30)
-
- Site-Selective, Remote sp3 C?H Carboxylation Enabled by the Merger of Photoredox and Nickel Catalysis
-
A photoinduced carboxylation of alkyl halides with CO2 at remote sp3 C?H sites enabled by the merger of photoredox and Ni catalysis is described. This protocol features a predictable reactivity and site selectivity that can be modulated by the ligand backbone. Preliminary studies reinforce a rationale based on a dynamic displacement of the catalyst throughout the alkyl side chain.
- Sahoo, Basudev,Bellotti, Peter,Juliá-Hernández, Francisco,Meng, Qing-Yuan,Crespi, Stefano,K?nig, Burkhard,Martin, Ruben
-
supporting information
p. 9001 - 9005
(2019/06/24)
-
- Cyclohexyl-Fused, Spirobiindane-Derived, Phosphine-Catalyzed Synthesis of Tricyclic ?3-Lactams and Kinetic Resolution of ?3-Substituted Allenoates
-
A C2-symmetric chiral phosphine catalyst, NUSIOC-Phos, which can be easily derived from cyclohexyl-fused spirobiindane, was introduced. A highly enantioselective domino process involving pyrrolidine-2,3-diones and γ-substituted allenoates catalyzed by NUSIOC-Phos has been disclosed. Diastereospecific tricyclic γ-lactams containing five contiguous stereogenic centers were obtained in high yields and with nearly perfect enantioselectivities. A kinetic resolution process of racemic γ-substituted allenoates was developed for the generation of optically enriched chiral allenoates.
- Wu, Mingyue,Han, Zhaobin,Li, Kaizhi,Wu, Ji'En,Ding, Kuiling,Lu, Yixin
-
supporting information
p. 16362 - 16373
(2019/10/16)
-
- Preparation method of organic carboxylic acid
-
The invention discloses a preparation method of organic carboxylic acid. The preparation method comprises the following steps that catalysts, olefins, water and solvents are added into a reaction container; CO is introduced; heating reaction is performed; after the reaction completion, separation is performed to obtain organic carboxylic acid; the catalysts comprise transition metal catalysts, ligands and catalysis assistants; the catalysis assistants comprise Lewis acid salt. The preparation method has the advantages that the dependency on protonic acid in the prior art is avoided; the Lewisacid salt is used as the catalysis assistant, so that the corrosion of a reaction system on equipment can be effectively prevented; the requirements on equipment are lowered. The preparation method has excellent substrate practicability; the operation steps are simple and fast; the reaction conditions are mild and are easy to control; the raw materials are cheap and can be easily obtained; the product yield and the product purity are high; the preparation method is suitable for large-scale industrial production; the normal/iso ratio of reaction products can be regulated and controlled throughthe catalysis assistants; the defects of regulating and controlling the normal/iso ratio of the reaction products by traditional phosphine ligands are overcome; the reaction progress of the reaction is simplified; the cost is favorably reduced.
- -
-
Paragraph 0071-0073
(2019/10/15)
-
- Synthesis, in vitro and in silico evaluation of diaryl heptanones as potential 5LOX enzyme inhibitors
-
A new series of diaryl heptanones (12a-q) were synthesized and their structures were confirmed by its 1H, 13C NMR and Mass spectral data. These analogs were evaluated for their anti-oxidant activity and potential to inhibit 5-lipoxygenase. Compounds 12k and 12o showed potent in vitro 5-lipoxygenase enzyme inhibitory activity with IC50 values of 22.2, 21.5 μM, which are comparable to curcumin (24.4 μM). Further they also have shown significant antioxidant activity. Molecular docking studies clearly showed correlation between binding energy and potency of these compounds.
- Meka, Bharani,Ravada, Suryachandra Rao,Muthyala, Murali Krishna Kumar,Kurre, Purna Nagasree,Golakoti, Trimurtulu
-
p. 408 - 421
(2018/07/13)
-
- Silver(I)-Catalyzed Widely Applicable Aerobic 1,2-Diol Oxidative Cleavage
-
The oxidative cleavage of 1,2-diols is a fundamental organic transformation. The stoichiometric oxidants that are still predominantly used for such oxidative cleavage, such as H5IO6, Pb(OAc)4, and KMnO4, generate stoichiometric hazardous waste. Herein, we describe a widely applicable and highly selective silver(I)-catalyzed oxidative cleavage of 1,2-diols that consumes atmospheric oxygen as the sole oxidant, thus serving as a potentially greener alternative to the classical transformations.
- Zhou, Zhong-Zhen,Liu, Mingxin,Lv, Leiyang,Li, Chao-Jun
-
p. 2616 - 2620
(2018/02/13)
-
- Pd-Catalyzed β-C(sp3)?H Arylation of Propionic Acid and Related Aliphatic Acids
-
A generally applicable Pd-catalyzed protocol for the β-C(sp3)?H arylation of propionic acid and related α-branched aliphatic acids is reported. Enabled by the use of N-acetyl-β-alanine as ligand our protocol delivers a broad range of arylation products. Notably, the highly challenging substrate, propionic acid, which lacks any acceleration through the Thorpe–Ingold effect, can be employed as substrate with synthetically useful yields. Furthermore, the scalability and synthetic applicability of the protocol are demonstrated.
- Ghosh, Kiron K.,van Gemmeren, Manuel
-
supporting information
p. 17697 - 17700
(2017/12/07)
-
- Direct β-Selective Hydrocarboxylation of Styrenes with CO2 Enabled by Continuous Flow Photoredox Catalysis
-
The direct β-selective hydrocarboxylation of styrenes under atmospheric pressure of CO2 has been developed using photoredox catalysis in continuous flow. The scope of this methodology was demonstrated with a range of functionalized terminal styrenes, as well as α-substituted and β-substituted styrenes.
- Seo, Hyowon,Liu, Aofei,Jamison, Timothy F.
-
supporting information
p. 13969 - 13972
(2017/10/17)
-
- Enantioselective bioreduction of benzo-fused cyclic ketones with engineered: Candida glabrata ketoreductase 1-a promising synthetic route to ladostigil (TV3326)
-
Biocatalysis has been recently emerging as a promising alternative to traditional chemical synthesis because of its "green" characteristics and comparable selectivities, which accord with the concept of sustainable development and demand for asymmetric synthesis. In this study, whole-cell biocatalysts containing glucose dehydrogenase (GDH) and Candida glabrata ketoreductase 1 (CgKR1) variants were constructed. These biocatalysts were applied to the reduction of benzo-fused cyclic ketones and showed good to high activities and enantioselectivities. Particularly, CgKR1 variants displayed high activities (90.6%-98.4% conversions) and enantioselectivities (>99.9% ee) towards 5a, a key intermediate of ladostigil (TV3326). Based on these results, a chemoenzymatic synthesis of (S)-5b was developed by using biocatalytic asymmetric reduction as a key step, giving the product with a total yield of 34.0% and 99.9% ee.
- Ou-Yang, Jingping,Zhang, Wenhe,Qin, Fengyu,Zuo, Weiguo,Xu, Shaoyu,Wang, Yan,Qin, Bin,You, Song,Jia, Xian
-
supporting information
p. 7374 - 7379
(2017/09/25)
-
- Formononetin derivatives and preparation methods and medical application thereof
-
The invention relates to the field of pharmaceutical chemistry, and relates to formononetin derivatives and preparation methods and medical application thereof, in particular to formononetin derivatives with the general formula as shown in (I), preparation methods thereof, pharmaceutical compositions containing the compounds and medical application of the derivatives and the pharmaceutical compositions, particularly, application of the derivatives and the pharmaceutical compositions serving as drugs for preventing or treating hyperlipidaemia or obesity or type-II diabetes. Please see the formula in the description.
- -
-
Paragraph 0162; 0163; 0164
(2017/04/29)
-
- Metal-Free Chemoselective Oxidative Dehomologation or Direct Oxidation of Alcohols: Implication for Biomass Conversion
-
A transition metal-free, chemoselective reaction was performed using the sodium tert-butoxide-oxygen (NaOtBu-O2) system, resulting in either oxidative dehomologation or direct oxidation of alcohols. In particular, the newly developed protocol may be used to predict the major product formed, which depends on alkyl chain length of the alcohols and reaction conditions. The rational mechanism of this transformation was also demonstrated by performing an 18O isotopic labelling experiment. This protocol presents a straightforward method for biomass conversion of a lignin model compound to phenol and benzoic acid.
- Kim, Sun Min,Shin, Hun Yi,Kim, Dong Wan,Yang, Jung Woon
-
p. 241 - 245
(2016/02/27)
-
- Minimizing Aryloxy Elimination in RhI-Catalyzed Asymmetric Hydrogenation of β-Aryloxyacrylic Acids using a Mixed-Ligand Strategy
-
The first example of efficient asymmetric hydrogenation of challenging β-aryloxyacrylic acids was realized using a RhI-complex based on the heterocombination of a readily available chiral monodentate secondary phosphine oxide (SPO) and an achiral monodentate phosphine ligand as the catalyst. Excellent enantioselectivities (92->99% ee) were achieved for a wide variety of chiral β-aryloxypropionic acids with minor aryloxy elimination in most cases. The resultant products were readily transformed into biologically active compounds through simple synthetic manipulations.
- Li, Yang,Wang, Zheng,Ding, Kuiling
-
supporting information
p. 16387 - 16390
(2015/11/09)
-
- A biocompatible alkene hydrogenation merges organic synthesis with microbial metabolism
-
Organic chemists and metabolic engineers use orthogonal technologies to construct essential small molecules such as pharmaceuticals and commodity chemicals. While chemists have leveraged the unique capabilities of biological catalysts for small-molecule production, metabolic engineers have not likewise integrated reactions from organic synthesis with the metabolism of living organisms. Reported herein is a method for alkene hydrogenation which utilizes a palladium catalyst and hydrogen gas generated directly by a living microorganism. This biocompatible transformation, which requires both catalyst and microbe, and can be used on a preparative scale, represents a new strategy for chemical synthesis that combines organic chemistry and metabolic engineering. Reduction to practice: A hydrogenation reaction has been developed that employs hydrogen generated in situ by a microorganism and a biocompatible palladium catalyst to reduce alkenes on a synthetically useful scale. This type of transformation, which directly combines tools from organic chemistry with the metabolism of a living organism for small-molecule production, represents a new strategy for chemical synthesis.
- Sirasani, Gopal,Tong, Liuchuan,Balskus, Emily P.
-
supporting information
p. 7785 - 7788
(2014/08/05)
-
- Improved synthesis of natural ester sintenin and its analogues via Wittig reaction
-
The synthesis of a cytotoxic natural ester sintenin (7a) and twenty eight of its analogues including nitrogen-containing heterocyclic indole moiety (7b-7t), saturated (10a-10d) and unsaturated (10e-10h) amides were carried out by convenient route via one-pot Wittig reaction in aqueous medium with improved yield. A systematic structure activity relationship of sintenin ester was designed by chemically modified derivatives in order to get better cytotoxicity.
- Sharma, Mukul,Rajesh, U. Chinna,Rawat, Diwan S.
-
p. 1853 - 1860
(2014/01/17)
-
- Discovery of synthetic methoxy-substituted 4-phenylbutyric acid derivatives as chemical chaperones
-
In this study, we evaluated the chemical chaperone activity of synthetic 4-phenylbutyric acid (4-PBA) derivatives. These derivatives have a methoxy group at the benzene ring and/or longer or shorter fatty acid portions. Several 4-PBA derivatives demonstrated higher antiaggregation activity than 4-PBA. Moreover, 4-(4-methoxyphenyl)butanoic acid (7b) showed protective effects against endoplasmic reticulum stress-induced neuronal cell death.
- Mimori, Seisuke,Okuma, Yasunobu,Kaneko, Masayuki,Kawada, Koichi,Nomura, Yasuyuki,Murakami, Yasuoki,Hamana, Hiroshi
-
supporting information
p. 1051 - 1052
(2013/09/24)
-
- A simple and straightforward approach toward selective C=C bond reduction by hydrazine
-
A simple and straightforward method for reducing the C=C double bond with hydrazine is described. A number of representative C=C bonds in various steric and electronic environments were examined. Substituted alkenes can be selectively reduced in EtOH in the presence of hydrazine to give the corresponding products in up to 100% yields.
- Chen, Hao,Wang, Jianmin,Hong, Xuechuan,Zhou, Hai-Bing,Dong, Chune
-
supporting information
p. 758 - 761
(2012/11/07)
-
- Raney nickel-catalyzed hydrogenation of unsaturated carboxylic acids with sodium borohydride in water
-
A mild, selective, and green method for the reduction of unsaturated carboxylic acids with sodium borohydride-Raney nickel (W6) system in water is reported. This method is practical and safe and avoids use of organic solvents. Taylor & Francis Group, LLC.
- Rao, Gopal Krishna,Gowda, Narendra B.,Ramakrishna, Ramesha A.
-
experimental part
p. 893 - 904
(2012/02/01)
-
- Anchored Pd-complexes in mesoporous supports: Synthesis, characterization and catalysis studies for carbonylation reactions
-
Pd(pyca)(PPh3)(OTs) [pyca = 2-picolinate] complex is efficiently anchored inside different mesoporous matrices, such as MCM-41, MCM-48, SBA-15 using a molecular aminopropyl tether moiety employing different synthesis strategies. Thorough characterization of the materials using powder XRD, multinuclear (13C, 29Si, 31P) CP-MAS NMR, XPS, SEM, N2-sorption studies etc. confirmed the successful anchoring of the palladium complex to the walls of the support matrices thus establishing the synthesis protocols unambiguously. The catalysts were found to be highly active and selective for the carbonylation of different aryl olefins and alcohols. Consecutive recycling and successful reuse proved the stability and true heterogeneous nature of all the anchored catalysts, which is a substantial advancement over the existing heterogeneous catalysts for carbonylation.
- Sarkar, Bibhas R.,Chaudhari, Raghunath V.
-
p. 154 - 173
(2013/01/15)
-
- Three-chain truxene discotic liquid crystal showing high charged carrier mobility
-
A new truxene discotic liquid crystal possessing only three octyloxy chains (3C8OTRX) was studied on the mesomorphic and semiconducting properties to reveal that it exhibits a high drift mobility of positive carriers in the order of 10-2 cm2 V-1 s-1 in the hexagonal ordered columnar (Colho) mesophase.
- Zhao, Ke-Qing,Chen, Chao,Monobe, Hirosato,Hu, Ping,Wang, Bin-Qin,Shimizu, Yo
-
supporting information; experimental part
p. 6290 - 6292
(2011/07/08)
-
- Electrochemical hydrogenation of 3-(methoxyphenyl)propenoic acids
-
Electrosynthesis can successfully be used for double bond hydrogenation in 3-(methoxyphenyl)propenoic acids. The corresponding 3-(methoxyphenyl)propanoic acids were produced in a virtually quantitative yield under the conditions of both electrocatalytic hydrogenation at the Ni cathode modified by electrodeposited dispersed nickel in a DMF-H2O mixture in the presence of AcOH and direct electroreduction using mercury and glassycarbon cathodes in DMF with Bu4NClO4 as the supporting electrolyte, although the mechanisms of these processes are different.
- Korotaeva,Rubinskaya,Rybakova,Gultyai
-
experimental part
p. 63 - 68
(2011/08/07)
-
- Synthesis and biological evaluation of new flavonoid fatty acid esters with anti-adipogenic and enhancing glucose consumption activities
-
Oleoyl Formononetin (OF) has good weight loss activity and hypolipidemic activity, could improve insulin sensitivity and suppress adipogenesis. To acquire better biological activities, three series of flavonoid fatty acid esters were designed and synthesized by optimizing the structure of OF. Their bioactivities were assayed in vitro. Some of these novel compounds could effectively inhibit preadipocyte proliferation and adipogenesis. Moreover, they could enhance glucose consumption in adipocytes notably.
- Zhao, Wei,Sun, Jie,Xiang, Hua,Zeng, Yan-Yan,Li, Xiao-Bo,Xiao, Hong,Chen, De-Ying,Ma, Ren-Ling
-
experimental part
p. 3192 - 3203
(2011/06/24)
-
- Bipolar carrier transport in Tri-Substituted octyloxy-Truxene DLC
-
In this study, bipolar charge carrier transport of 2,7,12- trioctyloxytruxene has been studied by a time-of-flight method. The substance studied exhibits a hexagonal columnar mesophase of which melting and clearing points are 118C and 133C, respectively. Ambipolar electronic carrier transports were observed in the mesophase. The drift mobility measurements reveal it is in the order of 10-2cm2 V-1 s-1 in the Colh and it increases to 10-1cm2 V-1 s-1 at the columnar mesophase - metastable phase transition, indicating truxene is an interesting molecular core for mesophase semiconductors. Copyright Taylor & Francis Group, LLC.
- Monobe,Chen,Zhao,Hu,Miyake,Fujii,Ozaki,Shimizu
-
experimental part
p. 149 - 155
(2012/07/14)
-
- Rhodium(I)-catalyzed 1,4-addition of arylboronic acids to acrylic acid in water: One-step preparation of 3-arylpropionic acids
-
A practical method for the one-step preparation of 3-arylpropionic acids through rhodium-catalyzed 1,4-addition of arylboronic acids to acrylic acid is reported. The method is applicable to a broad scope of aryl boronic acids and displays a wide functional group tolerance operating in water as the optimal reaction medium. Georg Thieme Verlag Stuttgart · New York.
- Vautravers, Nicolas R.,Breit, Bernhard
-
supporting information; experimental part
p. 2517 - 2520
(2011/11/12)
-
- The Continuous-Flow Synthesis of Carboxylic Acids using CO2 in a Tube-In-Tube Gas Permeable Membrane Reactor
-
Keep it simple: A gas-liquid flow reactor has been developed based on a gas permeable tube-in-tube configuration which effectively delivers gas to a liquid substrate stream in a safe, continuous fashion. A series of carboxylic acids were prepared from the reaction of CO2 with a range of Grignard reagents (see picture).
- Polyzos, Anastasios,O'Brien, Matthew,Petersen, Trine P.,Baxendale, Ian R.,Ley, Steven V.
-
supporting information; experimental part
p. 1190 - 1193
(2011/04/18)
-
- Synthesis of the alkaloid tyroscherin by an aldol/Curtius strategy
-
The alkaloid tyroscherin (2), which contains a vicinal anti-amino alcohol subunit was prepared from 4-hydroxyphenylpropionic acid (5) and meso-diol 9. After desymmetrization of diol 9 and suitable protecting group manipulations, one terminus was extended via a Claisen rearrangement giving rise to enoate ent-15. The missing carbon on the other end could be incorporated using MeMgCl/CuBr·SMe2 leading eventually to aldehyde ent-22. The acylated oxazolidinone 32 derived from acid 5 and aldehyde ent-22 were combined in an aldol reaction. A subsequent Curtius rearrangement on the carboxylic group furnished the amino function of tyroscherin (2). In a proof of concept study the same strategy was used to prepare tyroscherin analog 28.
- Ugele, Markus,Maier, Martin E.
-
supporting information; scheme or table
p. 2633 - 2641
(2010/05/01)
-
- Tyrosinase inhibitory activities of cinnamic acid analogues
-
The aim of this study was to show how tyrosinase inhibitory activity is correlated with the structure of cinnamic acid derivatives. We synthesized cinnamic acid derivatives, and investigated their tyrosinase inhibitory and DPPH radical scavenging activities. The results show that reduction of C=C double bonds and the substituent group of cinnamic acid derivatives have an effect on antioxidant activity and tyrosinase inhibitory activity. Among these compounds, compounds 2, 6 and 6a showed a potent tyrosinase inhibitory activity with IC50 (50% inhibitory concentration) values of 115.6 μM, 114.9 μM and 195.7 μM, respectively. The results obtained provide a useful clue for the design and development of new tyrosinase inhibitors.
- Takahashi,Miyazawa, Mitsuo
-
experimental part
p. 913 - 918
(2011/08/06)
-
- FLAVAN-3-OL CONTAINING FOODSTUFFS
-
The use of a compound for the reduction or elimination of bitterness caused by flavan-3-ols is provided. Compositions having greater than 0.01 wt % flavan-3-ols and that comprise an effective amount of the compound are also provided. The compound conforms to the general formula (I): wherein R1 represents C2-C3 saturated or unsaturated divalent hydrocarbon radical, n is an integer from 0 to 3, and each X is independently selected from C1-C3 alkyloxy and OH; and wherein if n is 0 then R1 is C3 saturated divalent hydrocarbon radical or C2-C3 unsaturated divalent hydrocarbon radical; and wherein if n is greater than 0 then the compound has formula (II)
- -
-
-
- 1,4-Cyclohexadiene with Pd/C as a rapid, safe transfer hydrogenation system with microwave heating
-
A method for the rapid, safe hydrogenation of alkenes and deprotection of benzyl ethers and carboxybenzyl amides is described using catalytic transfer hydrogenation under microwave heating conditions. Commonly available Pd/C catalyst is extremely effective with 1,4-cyclohexadiene as the hydrogen transfer source. In general, the reactions are complete within five minutes at 100 °C.
- Quinn, John F.,Razzano, Dana A.,Golden, Kathryn C.,Gregg, Brian T.
-
scheme or table
p. 6137 - 6140
(2009/04/05)
-
- Catalytic transfer hydrogenation and hydrogenolysis in ionic liquids with Pd/MgLa mixed oxide and Pd/MgAl hydrotalcite as recyclable catalysts
-
A new Pd/MgLa mixed oxide and the known Pd/MgAl hydrotalcite catalysts were applied and recycled successfully in catalytic transfer hydrogenation reactions in ionic liquids. Some α,β-unsaturated carboxylic acid derivatives were hydrogenated in excellent yields. The catalysts were recycled without significant loss of activity. Besides that, a number of halogenated aromatic compounds were dehalogenated under similar catalytic transfer conditions. Copyright Taylor & Francis Group, LLC.
- Baan, Zoltan,Potor, Attila,Cwik, Agnieszka,Hell, Zoltan,Keglevich, Gyoergy,Finta, Zoltan,Hermecz, Istvan
-
p. 1601 - 1609
(2008/09/20)
-
- Palladium-catalyzed heck coupling-hydrogenation: Highly efficient one-pot synthesis of dibenzyls and alkyl phenyl esters
-
An efficient method for the synthesis of industrially important dibenzyls and alkyl phenyl esters via sequential Heck coupling and hydrogenation of the alkenyl double bond in one pot with a single recyclable catalyst under mild conditions has been realised. The catalyst was recovered by simple filteration and reused for several cycles with consistent activity.
- Kantam, M. Lakshmi,Chakravarti, Rajashree,Chintareddy, Venkat Reddy,Sreedhar,Bhargava, Suresh
-
supporting information; experimental part
p. 2544 - 2550
(2009/08/14)
-
- (1-Nosyl-5-nitroindol-3-yl)methyl ester: A novel protective group for carboxylic acids
-
(Chemical Equation Presented) The usefulness of (1-nosyl-5-nitroindol-3-yl) methyl esters as a novel protective group for carboxylic acid is fully demonstrated. The novel protective group is stable under a broad range of conditions and can easily be deprotected under the mild conditions used for removal of the nosyl (Ns) group. It is orthogonal to the existing protective groups for carboxylic acids such as t-butyl and allyl esters.
- Nishimura, Takuya,Yamada, Kouhei,Takebe, Tohru,Yokoshima, Satoshi,Fukuyama, Tohru
-
supporting information; experimental part
p. 2601 - 2604
(2009/05/26)
-
- Tris(2,4,6-trimethoxyphenyl)phosphine: Base catalyst in the transformation of α,β-unsaturated aldehydes to saturated carboxylic-acid derivatives
-
We have focused on the basicity of Tris(2,4,6-trimethoxyphenyl)phosphine (TTMPP) in organic synthesis. To extend the utility of TTMPP, we examined the reaction of α,β-unsaturated aldehydes with trimethylsilyl cyanide in the presence of TTMPP. Furthermore, to clarify the basic character of TTMPP, we measured 31P NMR of TTMPP and related compounds. First, the reaction of cinnamaldehydes with trimethylsilyl cyanide in the presence of a catalytic amount of TTMPP afforded the corresponding saturated carboxylic acids after hydrolysis with 1M HCl. Treatment of the reaction mixture with alcohols or amines instead of 1M HCl gave the corresponding saturated esters and amides, respectively. As a result of studies of the reaction mechanism, it was revealed that the reaction proceeded via silylcyanation of α,β-unsaturated aldehydes with trimethylsilyl cyanide to produce trimethylsilyl ethers of cyanohydrin and subsequent isomerization that formed α-trimethylsiloxy vinyl cyanides, which were hydrolyzed to give saturated carboxylic acids. Copyright Taylor & Francis Group, LLC.
- Hayashi, Masahiko,Kawabata, Hirotoshi,Yoshimoto, Kazuya,Tanaka, Takanori
-
p. 433 - 445
(2007/10/03)
-
- Extremely potent orally active benzo[g]quinoline analogue of the dopaminergic prodrug: 6-(N,N-Di-n-propyl)amino-3,4,5,6,7,8-hexahydro-2H- naphthalen-1-one
-
Enone prodrugs of dopaminergic catecholamines represent a new type of prodrug in the research area of dopamine agonists. Here, we demonstrate the first benzo[g]quinoline-derived enone that induces potent dopamine agonist effects similar to aminotetralin-derived enones. Significant effects of (-)-4 were observed in microdialysis studies after administration of 1 nmol kg -1 sc and 3 nmol kg-1 po. With a potency comparable to that of the most potent apomorphines, (-)-4 could potentially compete with L-DOPA and apomorphine in the treatment of Parkinson's disease.
- Liu, Danyang,Wikstr?m, H?kan V.,Dijkstra, Durk,De Vries, Jan B.,Venhuis, Bastiaan J.
-
p. 1494 - 1498
(2007/10/03)
-
- Mild conversion of β-diketones and β-ketoesters to carboxylic acids
-
A mild protocol for the conversion of β-ketoesters and β-diketones to carboxylic acids with use of CAN in CH3CN is described. The method is compatible with a number of functional groups, and can generate carboxylic acids under neutral conditions at room temperature. The reaction is fast and general, providing an alternative method to the commonly used malonic ester acid preparation. Initial mechanistic studies show that initial oxidation of the enol form of the β-dicarbonyl initiates the reaction. The presence of nitrate as an oxidant ligand or as an additive is critical for success of the reaction.
- Zhang, Yang,Jiao, Jingliang,Flowers II, Robert A.
-
p. 4516 - 4520
(2007/10/03)
-
- Application of ionic liquids in palladium(II) catalyzed homogenous transfer hydrogenation
-
The first application of palladium(II) catalyzed homogenous transfer hydrogenations in ionic liquids is described. Cinnamic acid and its derivatives were reduced in high yields under mild conditions using ammonium formate as hydrogen donor.
- Baán, Zoltán,Finta, Zoltán,Keglevich, Gy?rgy,Hermecz, István
-
p. 6203 - 6204
(2007/10/03)
-
- Iron tricarbonyl stabilized pentadienyl cation as initiator for cascade polycyclizations: A diastereoselective entry into octahydrophenanthrenes
-
A new example is provided of completely diastereoselective polycyclization, affording the octahydrophenanthrene framework. Generation of an iron tricarbonyl stabilized pentadienyl carbocation is the triggering event of the cascade reaction. The carbocation is generated by anchimerically assisted regiospecific protonation of a double bond adjacent to the iron tricarbonyl diene moiety. Tetrafluoroboric acid ether complex appears to be the optimum reagent, affording good yields, even under catalytic conditions.
- Pearson, Anthony J.,Ghidu, Victor P.
-
p. 8975 - 8978
(2007/10/03)
-
- Swelled plastics in supercritical CO2 as media for stabilization of metal nanoparticles and for catalytic hydrogenation
-
Swelled plastics in supercritical carbon dioxide provide unique environments for stabilizing palladium and rhodium nanoparticles and for catalytic hydrogenation. Complete hydrogenation of benzene to cyclohexane can be achieved in 10 minutes using the plastic stabilized Rh nanoparticles at 50°C in supercritical CO2. High efficiency, reusability, and rapid separation of products are some advantages of the plastic stabilized metal nanoparticles for catalytic hydrogenation in supercritical CO2.
- Ohde, Hiroyuki,Ohde, Mariko,Wai, Chien M.
-
p. 930 - 931
(2007/10/03)
-
- Synthesis of 1,4:3,6-dianhydro-d-mannitol 2,5-(hydrogenphosphate) and its usage in palladium-catalyzed hydroxycarbonylation of styrene
-
Phosphorylation of 1,4:3,6-dianhydro-d-mannitol by phosphorus oxychloride in the presence of triethylamine followed by hydrolysis gave a cyclie hydrogen phosphate, which has the crystal structure of 6-hydroxy-6-oxo-2,5,7,10-tetraoxa-6-phospha-tricyclo[6.3.0.04,11]undecane. It was used as a chiral ligand in palladium-catalyzed hydroxycarbonylation of styrene. The regioselectivity was good, but the optical yield was limited.
- Jiang, Biao,Huang, Zuo-Gang,Cheng, Ke-Jun
-
p. 2797 - 2803
(2007/10/03)
-
- Direct synthesis of 3-arylpropionic acids by tetraphosphine/palladium catalysed Heck reactions of aryl halides with acrolein ethylene acetal
-
Through the use of [PdCl(C3H5)]2/Cis,cis, cis-1,2,3,4-tetrakis(diphenylphosphinomethyl)cyclopentane as a catalyst, a range of aryl bromides undergoes Heck reaction with acrolein ethylene acetal. With this acetal, the selective formation of 3-arylpropionic acids/esters was observed. The functional group tolerance on the aryl halide is remarkable; substituents such as fluoro, methyl, methoxy, acetyl, formyl, benzoyl, nitro or nitrile are tolerated. Furthermore, this catalyst can be used at low loading, even for reactions of sterically hindered aryl bromides. Graphical Abstract.
- Lemhadri, Mhamed,Doucet, Henri,Santelli, Maurice
-
p. 11533 - 11540
(2007/10/03)
-
- A Rapid and Efficient Microwave-Assisted Synthesis of Substituted 3-Phenylpropionic Acids from Benzaldehydes in Minutes
-
A convenient, inexpensive, and efficient synthesis of 3-phenylpropionic acids (1a-1f) by reacting benzaldehyde (2a-2f) and malonic acid in acetic acid and piperidine into cinnamic acid (3a-3f) in 77 to 89% followed by its reduction with PdCl2 in the biphase of formic acid and aqueous sodium hydroxide is reported under microwave irradiation which utilizes short reaction time ranging 5 to 7 min to provide 1a-1f in moderate to high yield (69-86%) depending upon methoxy, methylenedioxy, and hydroxy groups present at the phenyl ring.
- Sharma, Anuj,Joshi, Bhupendra P.,Sinha, Arun K.
-
p. 1186 - 1187
(2007/10/03)
-
- Lewis base-catalyzed transformation of α,β-unsaturated aldehydes to saturated carboxylic acids, esters and amides
-
The reactions of α,β-unsaturated aldehydes such as (E)-cinnamaldehyde and 2- or 4-methoxycinnamaldehyde with trimethylsilyl cyanide in the presence of a catalytic amount of a Lewis base such as TTMPP and DBU afforded the corresponding saturated carboxylic acids after hydrolysis.
- Kawabata, Hirotoshi,Hayashi, Masahiko
-
p. 5645 - 5647
(2007/10/03)
-