57293-19-3Relevant academic research and scientific papers
Visible Light-Mediated Conversion of Alcohols to Bromides by a Benzothiadiazole-Containing Organic Photocatalyst
Li, Run,Gehrig, Dominik W.,Ramanan, Charusheela,Blom, Paul W. M.,Kohl, Fabien F.,Wagner, Manfred,Landfester, Katharina,Zhang, Kai A. I.
, p. 3852 - 3859 (2019/07/15)
The search for metal-free, stable and high effective photocatalysts with sufficient photo-redox potentials remains a key challenge for organic chemists. Here, we present a benzothiadiazole-containing molecular organic photocatalyst with redox potentials of ?1.30 V and +1.64 V vs. SCE. The singlet state lifetime is 13 ns. Direct conversion from aliphatic alcohols to bromides has been conducted with the designed organic photocatalyst under visible light irradiation with high efficiency and selectivity. The catalytic efficiency of the novel benzothiadiazole-based photocatalyst is comparable with the state-of-art metal and non-metal catalysts. Furthermore, advanced photophysical studies including time-resolved photoluminescence and transient absorption spectroscopy offer a powerful support for photo-induced electron transfer from photocatalyst to the reactive substrates. Lastly, no photo-bleaching effect is observed, demonstrating the high stability and recyclable of the designed organic photocatalyst. (Figure presented.).
Chemical modification-mediated optimisation of bronchodilatory activity of mepenzolate, a muscarinic receptor antagonist with anti-inflammatory activity
Yamashita, Yasunobu,Tanaka, Ken-ichiro,Yamakawa,Asano,Kanda, Yuki,Takafuji,Kawahara, Masahiro,Takenaga, Mitsuko,Fukunishi, Yoshifumi,Mizushima
supporting information, p. 3339 - 3346 (2019/06/18)
The treatment for patients with chronic obstructive pulmonary disease (COPD) usually involves a combination of anti-inflammatory and bronchodilatory drugs. We recently found that mepenzolate bromide (1) and its derivative, 3-(2-hydroxy-2, 2-diphenylacetoxy)-1-(3-phenoxypropyl)-1-azoniabicyclo[2.2.2]octane bromide (5), have both anti-inflammatory and bronchodilatory activities. We chemically modified 5 with a view to obtain derivatives with both anti-inflammatory and longer-lasting bronchodilatory activities. Among the synthesized compounds, (R)-(–)-12 ((R)-3-(2-hydroxy-2,2-diphenylacetoxy)-1-(3-phenylpropyl)-1-azoniabicyclo[2.2.2]octane bromide) showed the highest affinity in vitro for the human muscarinic M3 receptor (hM3R). Compared to 1 and 5, (R)-(–)-12 exhibited longer-lasting bronchodilatory activity and equivalent anti-inflammatory effect in mice. The long-term intratracheal administration of (R)-(–)-12 suppressed porcine pancreatic elastase-induced pulmonary emphysema in mice, whereas the same procedure with a long-acting muscarinic antagonist used clinically (tiotropium bromide) did not. These results suggest that (R)-(–)-12 might be therapeutically beneficial for use with COPD patients given the improved effects seen against both inflammatory pulmonary emphysema and airflow limitation in this animal model.
Isoprenoid Biosynthesis Inhibitors Targeting Bacterial Cell Growth
Desai, Janish,Wang, Yang,Wang, Ke,Malwal, Satish R.,Oldfield, Eric
, p. 2205 - 2215 (2016/10/22)
We synthesized potential inhibitors of farnesyl diphosphate synthase (FPPS), undecaprenyl diphosphate synthase (UPPS), or undecaprenyl diphosphate phosphatase (UPPP), and tested them in bacterial cell growth and enzyme inhibition assays. The most active compounds were found to be bisphosphonates with electron-withdrawing aryl-alkyl side chains which inhibited the growth of Gram-negative bacteria (Acinetobacter baumannii, Klebsiella pneumoniae, Escherichia coli, and Pseudomonas aeruginosa) at ～1–4 μg mL?1levels. They were found to be potent inhibitors of FPPS; cell growth was partially “rescued” by the addition of farnesol or overexpression of FPPS, and there was synergistic activity with known isoprenoid biosynthesis pathway inhibitors. Lipophilic hydroxyalkyl phosphonic acids inhibited UPPS and UPPP at micromolar levels; they were active (～2–6 μg mL?1) against Gram-positive but not Gram-negative organisms, and again exhibited synergistic activity with cell wall biosynthesis inhibitors, but only indifferent effects with other inhibitors. The results are of interest because they describe novel inhibitors of FPPS, UPPS, and UPPP with cell growth inhibitory activities as low as ～1–2 μg mL?1.
Inhibition of tyrosine phenol-lyase by tyrosine homologues
Do, Quang,Nguyen, Giang T.,Phillips, Robert S.
, p. 2243 - 2251 (2016/08/26)
We have designed, synthesized, and evaluated tyrosine homologues and their O-methyl derivatives as potential inhibitors for tyrosine phenol lyase (TPL, E.C. 4.1.99.2). Recently, we reported that homologues of tryptophan are potent inhibitors of tryptophan indole-lyase (tryptophanase, TIL, E.C. 4.1.99.1), with Ki values in the low μM range (Do et al. Arch Biochem Biophys 560:20–26, 2014). As the structure and mechanism for TPL is very similar to that of TIL, we postulated that tyrosine homologues could also be potent inhibitors of TPL. However, we have found that homotyrosine, bishomotyrosine, and their corresponding O-methyl derivatives are competitive inhibitors of TPL, which exhibit Ki values in the range of 0.8–1.5?mM. Thus, these compounds are not potent inhibitors, but instead bind with affinities similar to common amino acids, such as phenylalanine or methionine. Pre-steady-state kinetic data were very similar for all compounds tested and demonstrated the formation of an equilibrating mixture of aldimine and quinonoid intermediates upon binding. Interestingly, we also observed a blue-shift for the absorbance peak of external aldimine complexes of all tyrosine homologues, suggesting possible strain at the active site due to accommodating the elongated side chains.
Palladium-Catalyzed Alkoxycarbonylation of Unactivated Secondary Alkyl Bromides at Low Pressure
Sargent, Brendon T.,Alexanian, Erik J.
supporting information, p. 7520 - 7523 (2016/07/06)
Catalytic carbonylations of organohalides are important C-C bond formations in chemical synthesis. Carbonylations of unactivated alkyl halides remain a challenge and currently require the use of alkyl iodides under harsh conditions and high pressures of CO. Herein we report a palladium-catalyzed alkoxycarbonylation of secondary alkyl bromides that proceeds at low pressure (2 atm CO) under mild conditions. Preliminary mechanistic studies are consistent with a hybrid organometallic-radical process. These reactions efficiently deliver esters from unactivated alkyl bromides across a diverse range of substrates and represent the first catalytic carbonylations of alkyl bromides with carbon monoxide.
Scalable anti-Markovnikov hydrobromination of aliphatic and aromatic olefins
Galli, Marzia,Fletcher, Catherine J.,Del Pozo, Marc,Goldup, Stephen M.
supporting information, p. 5622 - 5626 (2016/07/06)
To improve access to a key synthetic intermediate we targeted a direct hydrobromination-Negishi route. Unsurprisingly, the anti-Markovnikov addition of HBr to estragole in the presence of AIBN proved successful. However, even in the absence of an added initiator, anti-Markovnikov addition was observed. Re-examination of early reports revealed that selective Markovnikov addition, often simply termed "normal" addition, is not always observed with HBr unless air is excluded, leading to the rediscovery of a reproducible and scalable initiator-free protocol.
Cyclohexanones by Rh-mediated intramolecular C-H insertion
Taber, Douglass F.,Paquette, Craig M.,Gu, Peiming,Tian, Weiwei
, p. 9772 - 9780 (2013/10/22)
Some long chain α-aryl α-diazo ketones under Rh catalysis cyclize efficiently to the corresponding cyclohexanones. This is in marked contrast to the cyclizations of α-diazo β-ketoesters, which consistently deliver cyclopentanone products.
Visible-light-mediated conversion of alcohols to halides
Dai, Chunhui,Narayanam, Jagan M.R.,Stephenson, Corey R.J.
experimental part, p. 140 - 145 (2012/02/06)
The development of new means of activating molecules and bonds for chemical reactions is a fundamental objective for chemists. In this regard, visible-light photoredox catalysis has emerged as a powerful technique for chemoselective activation of chemical bonds under mild reaction conditions. Here, we report a visible-light-mediated photocatalytic alcohol activation, which we use to convert alcohols to the corresponding bromides and iodides in good yields, with exceptional functional group tolerance. In this fundamentally useful reaction, the design and operation of the process is simple, the reaction is highly efficient, and the formation of stoichiometric waste products is minimized.
AMINE COMPOUND AND PHARMACEUTICAL USE THEREOF
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Page/Page column 46, (2010/04/25)
Provided is a novel amine compound represented by the following formula (I) having a superior peripheral blood lymphocyte decreasing action and superior in the immunosuppressive action, rejection suppressive action and the like, which shows decreased side effects of, for example, bradycardia and the like, or a pharmaceutically acceptable acid addition salt thereof, or a hydrate thereof, or a solvate thereof. wherein each symbol is as defined in the specification.
