- Preparation method of 2 -bromo -4-chlorobenzaldehyde
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The invention relates to a preparation method of 2 -bromo -4-chlorobenzaldehyde and belongs to the field of medicinal chemistry. The preparation method can obtain 2 -bromo -4-chlorobenzaldehyde by taking nitrotoluene as a starting material through substitution, reduction, substitution, substitution, substitution, hydrolysis and elimination reaction. Compared with the prior art, the method shortens the reaction time, the reaction temperature is higher 120 °C or higher, the reaction conditions are mild, the yield of the obtained product is about 70% and more than 90%. The reaction temperature is reduced, high-boiling-point solvent is not needed to participate in the reaction, the post-treatment is simple, and the method is more suitable for industrial production with strict safety and environmental protection.
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- Synergistic effects in Fe nanoparticles doped with ppm levels of (Pd + Ni). A new catalyst for sustainable nitro group reductions
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A remarkable synergistic effect has been uncovered between ppm levels of Pd and Ni embedded within iron nanoparticles that leads to mild and selective catalytic reductions of nitro-containing aromatics and heteroaromatics in water at room temperature. NaBH4 serves as the source of inexpensive hydride. Broad substrate scope is documented, along with several other features including: low catalyst loading, low residual metal in the products, and recycling of the catalyst and reaction medium, highlight the green nature of this new technology.
- Pang, Haobo,Gallou, Fabrice,Sohn, Hyuntae,Camacho-Bunquin, Jeffrey,Delferro, Massimiliano,Lipshutz, Bruce H.
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supporting information
p. 130 - 135
(2018/01/12)
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- Iridium-catalyzed transfer hydrogenation of nitroarenes to anilines
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A simple and general homogeneous catalyst system composed of commercially available [Ir(cod)Cl]2 and 1,10-phenanthroline has been developed for the selective transfer hydrogenation of nitroarenes to anilines. It utilized the readily accessible 2-propanol as a hydrogen donor and had wide substrate scope. A careful mechanistic investigation through real-time detection and a series of controlled experiments with possible intermediates was also carried out, which showed that the transformation proceeds via both phenylhydroxylamine and azobenzene intermediates and the reduction of hydrazobenzene leading to aniline might be the rate-determining step.
- Chen, Shujie,Lu, Guoping,Cai, Chun
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p. 5360 - 5365
(2015/07/07)
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- Chemoselective reductions of nitroaromatics in water at room temperature
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A robust and green protocol for the reduction of functionalized nitroarenes to the corresponding primary amines has been developed. It relies on inexpensive zinc dust in water containing nanomicelles derived from the commercially available designer surfactant TPGS-750-M. This mild process takes place at room temperature and tolerates a wide range of functionalities. Highly selective reductions can also be achieved in the presence of common protecting groups.
- Kelly, Sean M.,Lipshutz, Bruce H.
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supporting information
p. 98 - 101
(2014/01/23)
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- Structure elucidation and enantioselective total synthesis of the HMG-CoA reductase inhibitors FR901512 and FR901516
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The enantioselective total synthesis of the potent HMGCoA reductase inhibitors FR901512 (1) and FR901516 (2) is reviewed. FR901512 was prepared in 15 steps from commercially available compound via 2 in 16.3% overall yield (89% average yield). This study validated the applicability and reliability of the catalytic asymmetric Nozaki-Hiyama reactions that were developed by us. These reactions enabled the concise, efficient, and protecting-group-free enantioselective total syntheses of these new statins.
- Inoue, Masahiro,Nakada, Masahisa
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scheme or table
p. 3694 - 3707
(2010/03/30)
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- Electronic effects of ring substituents on triplet benzylic biradicals
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UV irradiation of α-(o-alkylphenyl)acetophenones with a methoxy or cyano substituent para to the o-alkyl group of the α-aryl ring has revealed that a methoxy group slightly increases the stereoselectivity but not the quantum yield of indanol formation, whereas a cyano group greatly lowers both diastereoselectivity and quantum efficiency, confirming the likelihood that hydrogen-bonding of the hydroxy group to the α-phenyl ring plays an important role in the cyclization of the photogenerated triplet 1,5-biradical intermediates.
- Wagner, Peter J.,Wang, Lingling
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p. 645 - 647
(2007/10/03)
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- N-substituted heterocycles for the treatment of hypercholesteremia, dyslipidemia and other metabolic disorders; cancer, and other diseases
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The present invention relates to certain compounds of Formula (I) which can be useful in the treatment of diseases, such as, cancer, metabolic disorders, Type 2 Diabetes, dyslipidemia and/or hyperchloesterolemia:
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- Oxime derivatives for the treatment of dyslipidemia and hypercholesteremia
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The present invention relates to compounds of Formula (I) which may be useful in the treatment of diseases, such as, metabolic disorders, dyslipidemia and/or hyperchloesterolemia: 1
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- RXR activating molecules
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Disclosed are molecules that activate an RXR receptor, wherein the molecule comprises an RXR binding portion which binds the RXR receptor and comprises a side pocket contacting residue which contacts a side-pocket 1 of an RXR receptor.
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- Triaromatic vitamin D analogues
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The invention relates, as novel and useful industrial products, to triaromatic compounds, which are vitamin D analogues, of general formula (I): and also to a method for preparing them and to their use in pharmaceutical compositions intended for use in human or veterinary medicine, or alternatively in cosmetic compositions.
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- Synthesis, absorption and luminescence of a new series of soluble distyrylbenzenes featuring cyano substituents at the peripheral rings
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The synthesis of a complete series of nine soluble distyrylbenzenes (DSBs) with two (2a-c) and four cyano groups (1a-f) attached to the peripheral aromatic rings is reported. They were prepared by the Wittig reaction and characterized by 1H and 13C NMR, FT-IR, UV/Vis, PL, EL, mass spectra, and elemental analysis. The optical properties have been studied in detail to monitor structure-luminescence relationships as a function of the position of the cyano moieties. The DSBs with cyano substituents show bathochromic shifts in their absorption spectra when compared to the parent DSB (30). The extent of this red-shift depends on electronic and steric factors. The bis(p-cyano)-substituted compound 2c exhibits a small Stokes shift and a remarkably high quantum yield of ψF = 0.6-0.8 in the solid state. All the new distyrylbenzenes show electroluminescence when employed in devices with an ITO/PcCu/DSB/Al configuration and with colors ranging from red to green.
- Schweikart, Karl-Heinz,Hanack, Michael,Lueer, Larry,Oelkrug, Dieter
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p. 293 - 302
(2007/10/03)
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- Bromination of anilines in superacids
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In HF-SbF5, bromination of aniline at -40 deg C by Br2 ( 0.6 equivalent) yields monobromoderivatives 2a (3percent), 2b (24percent) and 2c (50percent), the electrophile reacting on the anilinium ion.These percentages reflect the relative reactivities in the ortho, meta and para positions, no isomerization occuring either in the intermediate arenium ions or in the products.At room temperature, the products equilibrate (2a/2b/2c: 3/50/47), the process being intramolecular and proceeding by 1,2 Br shifts.Dibromation of aniline (Br2/substrate: 1.2 equivalent) gives compounds 3a (10percent) and 3b (55percent), the second bromination being controlled, in the corresponding anilinium ion, by the first introduced atom.In similar conditions toluidines 4a and 5a yield bromoderivatives 4b (80percent) and 5b (47percent), respectively.
- Berrier C.,Jacquesy, J. C.,Renoux, A.
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- SELECTIVITY AND MECHANISM IN THE SIDE-CHAIN HALOGENATION OF METHYLBENZENES PROMOTED PHOTOCHEMICALLY AND BY METAL COMPLEXES IN THE PRESENCE OF HALIDE IONS
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The intramolecular selectivity in a variety of side-chain halogenations of alkyl-aromatics has been determined in AcOH by measuring the isomeric distribution in the reactions of 4-t-butyl- and 4-chloro-1,2-dimethylbenzene (1 and 2, respectively) with: Br2/hν, CAN/Br-, CAN=cerium(IV) ammonium nitrate, cobalt(III) acetate/Br-, S2O8=/Br-, N-bromosuccinimide (in CCl4), Cl2/hν, CAN/Cl-, cobalt(III) acetate/Cl-.In the bromination reactions selectivity is independent of the reaction conditions, thus suggesting that in all brominating systems Br. is the actual reacting species.Very surprisingly, with 1 as the substrate, Cl2/hν is a more selective system than Br2/hν.With 2 the two systems display similar selectivity.It has been suggested that in AcOH the transition state for photochlorination has an electron transfer character which increases as the substrate becomes more electron rich.The idea of a "variable" transition state for the photochlorination in AcOH is supported by data of relative reactivity of substituted toluenes indicating that the effect on the rate increases as the substituent becomes more electron donor.AcOH must have an essential role in this respect since in CCl4 situation returns to be "normal" with chlorination less selective than bromination.Selectivity of CAN/Cl- is very similar to that of Cl2/hν, whereas significant differences are observed with cobalt(III) acetate/Cl-.Probably Cl. and a cobalt(III) chloride complex are the reacting species in CAN/Cl- and cobalt(III) acetate/Cl-, respectively.
- Baciocchi, Enrico,Crescenzi, Manuela
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p. 6525 - 6536
(2007/10/02)
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