- A Magnetically Recyclable Palladium-Catalyzed Formylation of Aryl Iodides with Formic Acid as CO Source: A Practical Access to Aromatic Aldehydes
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A magnetically recyclable palladium-catalyzed formylation of aryl iodides under CO gas-free conditions has been developed by using a bidentate phosphine ligand-modified magnetic nanoparticles-anchored- palladium(II) complex [2P-Fe 3O 4@SiO 2-Pd(OAc) 2] as catalyst, yielding a wide variety of aromatic aldehydes in moderate to excellent yields. Here, formic acid was employed as both the CO source and the hydrogen donor with iodine and PPh 3as the activators. This immobilized palladium catalyst can be obtained via a simple preparative procedure and can be facilely recovered simply by using an external magnetic field, and reused at least 9 times without any apparent loss of catalytic activity.
- You, Shengyong,Zhang, Rongli,Cai, Mingzhong
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p. 1962 - 1970
(2021/01/25)
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- Oxidation of aromatic and aliphatic aldehydes to carboxylic acids by Geotrichum candidum aldehyde dehydrogenase
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Oxidation reaction is one of the most important and indispensable organic reactions, so that green and sustainable catalysts for oxidation are necessary to be developed. Herein, biocatalytic oxidation of aldehydes was investigated, resulted in the synthesis of both aromatic and aliphatic carboxylic acids using a Geotrichum candidum aldehyde dehydrogenase (GcALDH). Moreover, selective oxidation of dialdehydes to aldehydic acids by GcALDH was also successful.
- Hoshino, Tomoyasu,Yamabe, Emi,Hawari, Muhammad Arisyi,Tamura, Mayumi,Kanamaru, Shuji,Yoshida, Keisuke,Koesoema, Afifa Ayu,Matsuda, Tomoko
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- Nickel-catalyzed carboxylation of aryl iodides with lithium formate through catalytic CO recycling
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A protocol for the Ni-catalyzed carboxylation of aryl iodides with formate has been developed with good functional group compatibility for the synthesis of a variety of aromatic carboxylic acids under mild conditions. The reaction tolerates other functionalities for cross-coupling, such as aryl bromide, aryl chloride, aryl tosylate, and aryl pinacol boronate. The reaction proceeds through a carbonylation process with in situ generated carbon monoxide in the presence of a catalytic amount of acetic anhydride and lithium formate, avoiding the use of gaseous CO. The strategy of CO recycling in catalytic amounts is critical for the success of the reaction.
- Fu, Ming-Chen,Fu, Yao,Shang, Rui,Wu, Ya-Nan
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supporting information
p. 4067 - 4069
(2020/04/20)
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- Preparation method of 3-carboxybenzaldehyde
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The invention discloses a preparation method of 3-carboxybenzaldehyde. The method comprises the following steps: by using m-toluonitrile as a starting raw material, carrying out a first hydrolysis reaction, and adding an acid to carry out an acidification reaction to obtain m-toluic acid; carrying out chlorination reaction on m-toluic acid to obtain 3-carboxyl benzyl chloride; mixing the 3-carboxyl benzyl chloride and urotropin for an oxidation reaction, then adding glacial acetic acid and water for a second hydrolysis reaction to obtain the 3-carboxybenzaldehyde. According to the method disclosed by the invention, m-toluonitrile with low cost is used as a raw material, the 3-carboxybenzaldehyde is synthesized through a series of processes of hydrolysis, chlorination, oxidation and hydrolysis, and the product purity and yield are relatively high; the method has the advantages of simple and safe process operation, easily available raw materials and low cost and is suitable for industrial production.
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Paragraph 0040; 0043; 0045; 0048; 0050; 0053
(2020/04/29)
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- Bisubstrate inhibitors of nicotinamide N-methyltransferase (NNMT) with enhanced activity
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Nicotinamide N-methyltransferase (NNMT) catalyzes the methylation of nicotinamide to form N-methylnicotinamide. Overexpression of NNMT is associated with a variety of diseases, including a number of cancers and metabolic disorders, suggesting a role for NNMT as a potential therapeutic target. By structural modification of a lead NNMT inhibitor previously developed in our group, we prepared a diverse library of inhibitors to probe the different regions of the enzyme's active site. This investigation revealed that incorporation of a naphthalene moiety, intended to bind the hydrophobic nicotinamide binding pocket via π-πstacking interactions, significantly increases the activity of bisubstrate-like NNMT inhibitors (half-maximal inhibitory concentration 1.41 μM). These findings are further supported by isothermal titration calorimetry binding assays as well as modeling studies. The most active NNMT inhibitor identified in the present study demonstrated a dose-dependent inhibitory effect on the cell proliferation of the HSC-2 human oral cancer cell line.
- Gao, Yongzhi,Van Haren, Matthijs J.,Moret, Ed E.,Rood, Johannes J. M.,Sartini, Davide,Salvucci, Alessia,Emanuelli, Monica,Craveur, Pierrick,Babault, Nicolas,Jin, Jian,Martin, Nathaniel I.
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p. 6597 - 6614
(2019/08/20)
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- SO2F2-Mediated One-Pot Synthesis of Aryl Carboxylic Acids and Esters from Phenols through a Pd-Catalyzed Insertion of Carbon Monoxide
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A one-pot Pd-catalyzed carbonylation of phenols into their corresponding aryl carboxylic acids and esters through the insertion of carbon monoxide has been developed. This procedure offers a direct synthesis of aryl carboxylic acids and esters from inexpensive and abundant starting materials (phenols, SO2F2 and CO) under mild conditions. This method tolerates a broad range of functional groups and is also applicable for the modification of complicated natural products.
- Fang, Wan-Yin,Leng, Jing,Qin, Hua-Li
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supporting information
p. 2323 - 2331
(2017/09/06)
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- Palladium-Catalyzed Formylation of Aryl Iodides with HCOOH as CO Source
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A facile and practical method for the synthesis of aromatic aldehydes by palladium-catalyzed reductive carbonylation starting from aryl iodides and HCOOH is described. Compared to the known formylation procedure, HCOOH serves not only as the most convenient and environmental-friendly C1 source but also as the reviving agent in the reductive elimination process of a Pd-catalyst. Furthermore, this procedure is also applied successfully to the modification of natural products, such as vindoline, tabersonin, and vincamine, to obtain the corresponding products in good yields.
- Sun, Guanglong,Lv, Xue,Zhang, Yinan,Lei, Min,Hu, Lihong
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supporting information
p. 4235 - 4238
(2017/08/23)
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- IONIC LIQUID COMPOSITION
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The present disclosure provides a composition for preparing aryl carboxylic acid; said composition comprising: at least one ionic liquid, at least one catalyst, at least one non-oxidizable polar solvent, and at least one oxidizable multi-alkylated arylene compound with no two successive ring positions bearing alkyl group. The present disclosure also provides a process for preparing aryl carboxylic acid.
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Paragraph 0105-0106
(2016/05/19)
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- Iron oxalate capped iron-copper nanomaterial for oxidative transformation of aldehydes
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An efficient, sustainable and green procedure for the synthesis of selective orthorhombic iron(oxalate) capped Fe-Cu bimetallic oxide nanomaterial [Fe(ox)Fe-CuOx] was developed using a sodium borohydride reduction of iron(ii) salt in the presence of oxalic acid at room temperature followed by addition of copper sulfate in water. The reported method is a cost-effective chemical route for producing [Fe(ox)Fe-CuOx] nano material at the gram level with a surface area of 78.4 m2 g-1 and a pore volume of 0.141 cm3 g-1. The [Fe(ox)Fe-CuOx] nanomaterials were found to be useful as a recoverable catalyst for the oxidative transformation of an aldehyde to its corresponding ester and acid in presence of hydrogen peroxide.
- Kashyap, Rajarshi,Talukdar, Dhruba Joyti,Pratihar, Sanjay
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p. 1430 - 1437
(2015/02/19)
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- Development of a Rhodium(II)-Catalyzed Chemoselective C(sp3)-H Oxygenation
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We report the first example of RhII-catalyzed chemoselective double C(sp3)-H oxygenation, which can directly transform various toluene derivatives into highly valuable aromatic aldehydes with great chemoselectivity and practicality. The critical combination of catalyst Rh(OAc)2, oxidant Selectfluor, and solvents of TFA/TFAA promises the successful delivery of the oxidation with satisfactory yields. A possible mechanism involving a unique carbene-Rh complex is proposed, and has been supported by both experiments and theoretical calculations.
- Lin, Yun,Zhu, Lei,Lan, Yu,Rao, Yu
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supporting information
p. 14937 - 14942
(2015/10/19)
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- Ligand-Free Palladium-Catalyzed Hydroxycarbonylation of Aryl Halides under Ambient Conditions: Synthesis of Aromatic Carboxylic Acids and Aromatic Esters
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Aryl halides were readily converted into their corresponding aromatic carboxylic acids in high yields with high selectivity by ligand-free palladium-catalyzed hydroxycarbonylation at room temperature and atmospheric pressure. The new method is operationally simple and scalable. In addition, aromatic esters were easily synthesized through one-pot hydroxycarbonylation/alkylation with alkyl halides.
- Han, Wei,Jin, Fengli,Zhou, Qing
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p. 1861 - 1868
(2015/06/30)
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- Fabrication of three dimensional (3D) hierarchical Ag/WO3 flower-like catalyst materials for the selective oxidation of m-xylene to isophthalic acid
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A three dimensional (3D) hierarchical silver supported tungsten oxide flower-like microsphere catalyst has been fabricated using a cationic surfactant CTAB. It was found that the crystal-splitting mechanism plays a key role in the formation of this flower-like structure. This catalyst was proved to be highly effective in the liquid phase selective oxidation of m-xylene to isophthalic acid.
- Acharyya, Shankha S.,Ghosh, Shilpi,Bal, Rajaram
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supporting information
p. 5998 - 6001
(2015/03/30)
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- Silylation improves the photodynamic activity of tetraphenylporphyrin derivatives in vitro and in vivo
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The effects of silyl and hydrophilic groups on the photodynamic properties of tetraphenylporphyrin (TPP) derivatives have been studied in vitro and in vivo. Silylation led to an improvement in the quantum yield of singlet oxygen sensitization for both sulfo and carboxy derivatives, although the silylation did not affect other photophysical properties. Silylation also improved the cellular uptake efficiency for both sulfo and carboxy derivatives, enhancing the in vitro photodynamic activity of the photosensitizer in U251 human glioma cells. The carboxy derivative (SiTPPC4) was found to show higher cellular uptake efficiency and in vitro photodynamic activity than the corresponding sulfo derivative (SiTPPS4), which indicates that the carboxy group is a more promising hydrophilic group than the sulfo group in the silylated porphyrin. SiTPPC4 was found to show high selective accumulation efficiency in tumors, although almost no tumor selectivity was observed for the nonsilylated porphyrin. The concentration of SiTPPC4 in tumors was 13 times higher than that in muscle 12 h after drug administration. We also studied tumor response after treatment and found that silylation enhanced in vivo photodynamic activity significantly. SiTPPC 4 shows higher photodynamic activity than NPe6 with white light irradiation. Improved photosensitizers: Silylation improves the quantum yield of singlet oxygen sensitization, cellular uptake efficiency, and selective accumulation efficiency in tumors. As a result of these improvements, silylation significantly enhances photodynamic activity (see figure). The results of this work suggest that silylation is a promising strategy for improving photosensitizers for photodynamic therapy.
- Horiuchi, Hiroaki,Hosaka, Masahiro,Mashio, Hiroyuki,Terata, Motoki,Ishida, Shintaro,Kyushin, Soichiro,Okutsu, Tetsuo,Takeuchi, Toshiyuki,Hiratsuka, Hiroshi
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supporting information
p. 6054 - 6060
(2014/05/20)
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- NHC-catalysed highly selective aerobic oxidation of nonactivated aldehydes
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This publication describes a highly selective oxidation of aldehydes to the corresponding acids or esters. The reaction proceeds under metal-free conditions by using N-heterocyclic carbenes as organocatalysts in combination with environmentally friendly oxygen as the terminal oxidation agent.
- Moehlmann, Lennart,Ludwig, Stefan,Blechert, Siegfried
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p. 602 - 607
(2013/04/24)
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- Method for estimating SN1 rate constants: Solvolytic reactivity of benzoates
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Nucleofugalities of pentafluorobenzoate (PFB) and 2,4,6-trifluorobenzoate (TFB) leaving groups have been derived from the solvolysis rate constants of X,Y-substituted benzhydryl PFBs and TFBs measured in a series of aqueous solvents, by applying the LFER equation: log k = sf(Ef + Nf). The heterolysis rate constants of dianisylmethyl PFB and TFB, and those determined for 10 more dianisylmethyl benzoates in aqueous ethanol, constitute a set of reference benzoates whose experimental ΔG ? have been correlated with the ΔH? (calculated by PCM quantum-chemical method) of the model epoxy ring formation. Because of the excellent correlation (r = 0.997), the method for calculating the nucleofugalities of substituted benzoate LGs have been established, ultimately providing a method for determination of the SN1 reactivity for any benzoate in a given solvent. Using the ΔG? vs ΔH? correlation, and taking sf based on similarity, the nucleofugality parameters for about 70 benzoates have been determined in 90%, 80%, and 70% aqueous ethanol. The calculated intrinsic barriers for substituted benzoate leaving groups show that substrates producing more stabilized LGs proceed over lower intrinsic barriers. Substituents on the phenyl ring affect the solvolysis rate of benzhydryl benzoates by both field and inductive effects.
- Matic, Mirela,Denegri, Bernard,Kronja, Olga
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supporting information
p. 8986 - 8998,13
(2012/12/12)
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- Gold-catalyzed amide synthesis from aldehydes and amines in aqueous medium
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An efficient gold-catalyzed amide synthesis from aldehydes and amines in aqueous medium under mild reaction conditions has been developed.
- Li, Gai-Li,Kung, Karen Ka-Yan,Wong, Man-Kin
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supporting information; experimental part
p. 4112 - 4114
(2012/06/16)
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- Kinetics and oxidation of substituted benzyl alcohols by phenyliodoso acetate
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Oxidation of benzyl alcohol and some meta- and para- substituted alcohols by phenyliodoso acetate (PIA) in t-butyl alcohol-water medium (50:50) leads to the formation of corresponding benzaldehyde. The stoichiometry of the reaction was found to be 1:1. The reaction was first order each in substrate and oxidant concentrations. This reaction was studied at four different temperatures and the activation parameters were calculated. Correlation analysis was carried out using Taft's and Swain's dual substituent parameter (DSP) equation. The rate data of meta- compounds showed good correlation with (F,R) values, para-substituted benzyl alcohols showed good correlation with σIσR + A suitable mechanism has been proposed.
- Girija,Aruna
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experimental part
p. 264 - 268
(2012/02/02)
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- Process and Catalyst for Oxidizing Aromatic Compounds
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Catalytic compositions for conversion of substituted aromatic feed materials to oxidized products comprising aromatic carboxylic acid derivatives of the substituted aromatic feed materials comprise at least two metal or metalloid elements, at least one of which is palladium, platinum, vanadium or titanium, and at least one of which is a Group 5, 6, 14 or 15 metal or metalloid. A process for oxidizing substituted aromatic feed materials comprises contacting the feed material with oxygen in the presence of such a catalytic composition in a liquid reaction mixture.
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Page/Page column 18
(2009/04/24)
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- COMPOUNDS TO TREAT AMYLOIDOSIS AND PREVENT DEATH OF BETA-CELLS IN TYPE 2 DIABETES MELLITUS
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The invention discloses aromatic amides and sulfonates to treat or prevent type 2 diabetes mellitus (T2DM), the pathological consequences of T2DM, to inhibit amyloidosis or to prevent death of β-cells of the pancreas.
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Page/Page column 47; 48
(2010/11/24)
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- Oxidation of benzyl alcohol by pyridinium dichromate in acetonitrile. Using the paralmeta ratio of substituent effects for mechanism elucidation
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Rate constants were measured for the oxidation reaction of benzyl alcohol and twenty-five ortho-, recta- and para-monosubstituted derivatives in the temperature range 293-323 K at intervals of 10 K. The kinetics were followed spectrophotometrically in dry acetonitrile acidified with trichloroacetic acid (TCA) using pyridinium dichromate (PDC) as oxidising agent under pseudo-first-order conditions with respect to PDC. Benzaldehyde is the only oxidation product and no reaction takes place without TCA. From good linear Eyring plots activation enthalpies Δ?H° and entropies Δ?S° are calculated. For ortho-substituted benzyl alcohols high Δ?H° values and small negative Δ?S° values point to an ortho effect on the rate-determining step. Using the tetralinear approach to substituent effects, the average value λ = 1.09 ± 0.05 for the para/meta ratio of inductive or Electra effects is obtained and negative Hammett reaction constants decreasing in magnitude with increasing temperature are found. A mechanism implicating the prior acid-catalysed formation of neutral benzyl hydrogen dichromate ester followed by intramolecular proton transfer is proposed. Modelling of parameter λ in terms of the electrostatic theory showed its experimental value to be consistent with the ratio of electric potentials generated in the immediate vicinity of the nearest chromium atom by dipolar substituents introduced in the aromatic ring on para and meta positions. At a molecular level the oxidative, rate-determining step is suggested to be triggered by the retraction or shrinkage of electron pairs from sigma bonds in Cr2VI species to non-bonding orbitals in unstable CrIV-O-CrVI species. In contrast with past interpretations, an electrochemical approach is used to explain negative values for the Hammett reaction constant.
- Kabilan,Girija,Reis, Joao Carlos R.,Segurado, Manuel A.P.,De Oliveira, Jaime D. Gomes
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p. 1151 - 1157
(2007/10/03)
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- Isoquinoline compound melanocortin receptor ligands and methods of using same
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The invention relates to melanocortin receptor ligands and methods of using the ligands to alter or regulate the activity of a melanocortin receptor. The invention further relates to tetrahydroisoquinoline aromatic amines that function as melanocortin receptor ligands and as agents for controlling cytokine-regulated physiologic processes and pathologies, and combinatorial libraries thereof.
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