- Reduction over Condensation of Carbonyl Compounds through a Transient Hemiaminal Intermediate Using Hydrazine
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Reduction of carbonyl moieties to the corresponding alcohol using simply hydrazine hydrate has been considerably unfeasible until now due to the well-known condensation reaction. However, herein, we report that using an excess of 20-fold equivalents, the reduction proceeds in excellent yields. 1H NMR study of the reaction and density functional theory (DFT) calculations indicate that the final fate of the hemiaminal intermediate is crucial to obtain the alcohol or the hydrazone.
- Vilches-Herrera, Marcelo,Gallardo-Fuentes, Sebastián,Aravena-Opitz, Mauricio,Yá?ez-Sánchez, Mauricio,Jiao, Haijun,Holz, Jens,B?rner, Armin,Lühr, Susan
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p. 9213 - 9218
(2020/08/14)
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- In vitro study and structure-activity relationship analysis of stilbenoid derivatives as powerful vasorelaxants: Discovery of new lead compound
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The development of vasorelaxant as the antihypertensive drug is important as it produces a rapid and direct relaxation effect on the blood vessel muscles. Resveratrol (RV), as the most widely studied stilbenoid and the lead compound, inducing the excellent vasorelaxation effect through the multiple signalling pathways. In this study, the in vitro vascular response of the synthesized trans-stilbenoid derivatives, SB 1-8e were primarily evaluated by employing the phenylephrine (PE)-precontracted endothelium-intact isolated aortic rings. Herein we report trans-3,4,4′-trihydroxystilbene (SB 8b) exhibited surprisingly more than 2-fold improvement to the maximal relaxation (Rmax) of RV. This article also highlights the characterization of the aromatic protons in terms of their unique splitting patterns in 1H NMR.
- Chan, Sock Ying,Loh, Yean Chun,Oo, Chuan Wei,Yam, Mun Fei
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- Preparation method of sugar-reducing medicine dapagliflozin
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The invention discloses a preparation method for hypoglycemic drugdapagliflozin. The method comprises the steps that 4-hydroxybenzaldehyde is adopted as a starting raw material, alkylation, carbonyl reduction, chlorination and alkylation reaction with asepsin, diazotization and chlorination are performed to obtain a dapagliflozinmidbody 5-bromo-2-chloro-4'-ethyoxyl diphenylmethane, then, the midbody and 2,3,4,6-tetra-O-trimethyl silicone-D-glucolactone are subjected to condensation, etherification and methoxyl removal to obtain the hypoglycemic drugdapagliflozin. The raw materials adopted by the technological path are low in price and easy to obtain, the technology can achieve industrialization easily, and the final product is high in purity; the technological path is novel, the syntheticroute is short, no risky or complex technology exists in the reactions, equipment is simple, operation is easy and convenient, and the method is suitable for industrial production.
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Paragraph 0050; 0054-0056
(2019/10/01)
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- New convergent one pot synthesis of amino benzyl ethers bearing a nitrogen-containing bicycle
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We report herein a new convergent one pot method for the synthesis of amino benzyl ethers containing a bicyclic amine, derived from different substituted benzyl alcohols and bicyclic amino alcohols such as tropine, pseudotropine, and 3-quinuclidinol, using chlorotrimethylsilane and sodium iodide. In order to avoid the competitive reaction with the nitrogen atom, a solution of the separately prepared alkoxide of tropine, pseudotropine, and 3-quinuclidinol was added to the preformed substituted benzyl iodides and allowed to reflux at 90 °C for 15 h under nitrogen atmosphere. This method provides an efficient alternative of the preparation of amino benzyl ethers in organic synthesis with good yields in comparison with existed methods.
- López, Jhon J.,Pérez, Edwin G.
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p. 715 - 723
(2019/02/19)
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- Selective Hydroboration of Carboxylic Acids with a Homogeneous Manganese Catalyst
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Catalytic reduction of carboxylic acid to the corresponding alcohol is a challenging task of great importance for the production of a variety of value-added chemicals. Herein, a manganese-catalyzed chemoselective hydroboration of carboxylic acids has been developed with a high turnover number (>99?000) and turnover frequency (>2000 h-1) at 25 °C. This method displayed tolerance of electronically and sterically differentiated substrates with high chemoselectivity. Importantly, aliphatic long-chain fatty acids, including biomass-derived compounds, can efficiently be reduced. Mechanistic studies revealed that the reaction occurs through the formation of active manganese-hydride species via an insertion and bond metathesis type mechanism.
- Barman, Milan K.,Das, Kuhali,Maji, Biplab
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p. 1570 - 1579
(2019/01/30)
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- Novel leucine ureido derivatives as aminopeptidase N inhibitors using click chemistry
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The over-expression of aminopeptidase N on diverse malignant cells is associated with the tumor angiogenesis and metastasis. In this report, one new series of leucine ureido derivatives containing the triazole moiety was designed, synthesized and evaluated as APN inhibitors. Among them, compound 13v showed the best APN inhibition with an IC50 value of 0.089 ± 0.007 μM, which was two orders of magnitude lower than that of bestatin (IC50 = 9.4 ± 0.5 μM). Compound 13v also showed dose-dependent anti-angiogenesis activities. Even at the lower concentration (10 μM), compound 13v presented similar anti-angiogenesis activity compared with bestatin at 100 μM in both the human umbilical vein endothelial cells (HUVECs) capillary tube formation assay and the rat thoracic aorta rings test. Moreover, compared with bestatin, 13v exhibited comparable, if not better in vivo anti-metastasis activity in a mouse H22 pulmonary metastasis model.
- Cao, Jiangying,Ma, Chunhua,Zang, Jie,Gao, Shuai,Gao, Qianwen,Kong, Xiujie,Yan, Yugang,Liang, Xuewu,Ding, Qin'ge,Zhao, Chunlong,Wang, Binghe,Xu, Wenfang,Zhang, Yingjie
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p. 3145 - 3157
(2018/06/01)
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- Gadolinium Complex of 1,4,7,10-Tetraazacyclododecane-1,4,7-Trisacetic Acid (DO3A)-Ethoxybenzyl (EOB) Conjugate as a New Macrocyclic Hepatobiliary MRI Contrast Agent
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We report the synthesis of a macrocyclic Gd chelate based on a 1,4,7,10-Tetraazacyclododecane-1,4,7-Trisacetic acid (DO3A) coordinationn cage bearing an ethoxybenzyl (EOB) moiety and discuss its use as a T1 hepatobiliary magnetic resonance imaging (MRI) contrast agent. The new macrocyclic liver agent shows high chelation stability and high r1 relaxivity compared with linear-Type Gd chelates, which are the current clinically approved liver agents. Our macrocyclic, liver-specific Gd chelate was evaluated in vivo through biodistribution analysis and liver MRI, which demonstrated its high tumor detection sensitivity and suggested that the new Gd complex is a promising contrast agent for liver cancer imaging.
- Baek, Ah Rum,Kim, Hee-Kyung,Park, Subin,Lee, Gang Ho,Kang, Hyo Jeung,Jung, Jae-Chang,Park, Joon-Suk,Ryeom, Hun-Kyu,Kim, Tae-Jeong,Chang, Yongmin
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p. 4861 - 4868
(2017/06/28)
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- A Versatile Iridium(III) Metallacycle Catalyst for the Effective Hydrosilylation of Carbonyl and Carboxylic Acid Derivatives
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A versatile iridium(III) metallacycle catalysed rapidly and selectively the reduction of a large array of challenging esters and carboxylic acids as well as various ketones and aldehydes. The reactions proceeded in high yields at room temperature by hydrosilylation followed by desilylation. Although the reactions of various aldehydes and ketones resulted exclusively in alcohols, the hydrosilylation of esters led to alcohols or ethers, depending on the type of substrate. Regarding the carboxylic acids, again the nature of the reagent controlled the outcome of the hydrosilylation reaction, either alcohols or aldehydes being formed.
- Corre, Yann,Rysak, Vincent,Trivelli, Xavier,Agbossou-Niedercorn, Francine,Michon, Christophe
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p. 4820 - 4826
(2017/09/07)
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- An Efficient, Stable and Reusable Palladium Nanocatalyst: Chemoselective Reduction of Aldehydes with Molecular Hydrogen in Water
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Palladium nanoparticles (Pd-BNP) stabilized by a binaphthyl-backbone can be efficiently used for the chemoselective reduction of aldehydes in the presence of hydrogen at room temperature in water. The Pd-BNP catalyst is easily recovered and reused for five catalytic cycles. (Figure presented.).
- Kotha, Surya Srinivas,Sharma, Nidhi,Sekar, Govindasamy
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supporting information
p. 1694 - 1698
(2016/10/13)
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- Unexpectedly fast catalytic transfer hydrogenation of aldehydes by formate in 2-propanol-water mixtures under mild conditions
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Unsaturated aldehydes were efficiently reduced by transfer hydrogenation from sodium formate in water-2-propanol mixtures using a water-soluble Ru(II)-tertiary phosphine catalyst. The reaction yielded unsaturated alcohols with complete selectivity and without hydrogenation or isomerization of CC bonds of the substrates. Very high reaction rate was observed in the transfer hydrogenation of cinnamaldehyde already at 30 °C with turnover frequency of 160 h-1 and this increased to 3800 h-1 at 70 °C. Consequently, the method is applicable to the synthesis of unsaturated alcohols in case of heat sensitive or highly volatile aldehydes, too. Based on multinuclear NMR investigations, trans-[RuH2(H2O)(mtppms)3] is suggested as the key catalytic species.
- Szatmári, Imre,Papp, Gábor,Joó, Ferenc,Kathó, ágnes
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- β-cyclodextrin as inverse phase transfer catalyst on the electrocatalytic hydrogenation of organic compounds in water
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The optimum conditions for the electrocatalytic hydrogenation (ECH) of benzaldehyde in water, using a nickel sacrificial anode (SA) (referred to as ECH-SA) and β-cyclodextrin (β-CyD) as inverse phase transfer catalyst (IPTC) were determined. Four parameters were investigated: the morphology of the nickel deposited on the cathode matrix (Cu, Fe, Ni or Fe/Ni alloy (64:36)) during a pre-electrolysis, the size of the CyD cavity, the concentration of β-CyD, the supporting electrolyte concentration and the current density applied. The results showed that a Ni matrix together with ultrasound pre-electrolysis treatment allowed a nanostructured nickel deposit on the cathode surface. Under the best electrolysis conditions (2.8 mmol dm -3 of β-CyD, 1.0 mol dm-3 of NH4Cl and a current density of 330 mA dm-2), the yield of benzyl alcohol (99%) was 27% higher than that obtained under the same conditions but in the absence of β-CyD. Taking into account the hydrophobic character of the β-CyD, the best conditions of the ECH-SA method were applied to the hydrogenation of a variety of organic substrates. Excellent yields and current efficiencies were obtained with arylbenzaldehydes and acetophenone. ECH-SA of styrene gave moderate yield and current efficiency, and the hydrogenation of a terminal non-conjugated olefin (safrole) was not efficient.
- Vilar, Márcio,Navarro, Marcelo
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experimental part
p. 270 - 278
(2012/03/13)
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- INHIBITORS OF ACETYL-COA CARBOXYLASE
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The present invention relates to compounds that act as acetyl-CoA carboxylase (ACC) inhibitors. The invention also relates to methods of preparing the compounds, compositions containing the compounds, and to methods of treatment using the compounds.
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Page/Page column 62
(2010/11/17)
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- Design, synthesis and antiproliferative activity of tripentones: A new series of antitubulin agents
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Structure-activity relationship studies of a new series of tripentones (thieno[2,3-b]pyrrolizin-8-ones), led us to prepare several derivatives with antiproliferative activities. The most promising 3-(3-hydroxy-4-methoxyphenyl)thieno[2,3-b]pyrrolizin-8-one 20 (leukemia L1210, IC50 = 15 nM) was shown to be a potent inhibitor of tubulin polymerization.
- Lisowski, Vincent,Enguehard, Cecile,Lancelot, Jean-Charles,Caignard, Daniel-Henri,Lambel, Stephanie,Leonce, Stephane,Pierre, Alain,Atassi, Ghanem,Renard, Pierre,Rault, Sylvain
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p. 2205 - 2208
(2007/10/03)
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- Calcium uptake inhibitors
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This invention relates to 1-phenyl-3-phenyl-2-propyne-1-ones, the use of these compounds as calcium uptake inhibitors in leukocytes and thrombocytes, and pharmaceutical compositions containing these compounds as active ingredients, and the process of their preparation.
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