2635-13-4Relevant articles and documents
Synthesis of fused aromatic [1,3]dioxoles from 2-hydroxymethylphenols
Gesson, Jean-Pierre,Mondon, Martine,Pokrovska, Natacha
, p. 1395 - 1396 (1997)
The rearrangement of spiroepoxycyclohexadienones to benzo[1,3]dioxoles is best carred out in a non polar solvent (toluene, CCl4) in presence of TBDMSCl. Application to the synthesis of naphthalene and tetrahydronaphthalene derivatives is described.
Anti-inflammatory, ulcerogenic and platelet activation evaluation of novel 1,4-diaryl-1,2,3-triazole neolignan-celecoxib hybrids
Baroni, Adriano C. M.,Carvalho, Diego B.,Carvalho, Maria G.,Cassamale, Tatiana B.,Duarte, Rita C. F.,Felipe, Josyelen L.,Louren?o, Leticia D.,Toffoli-Kadri, Monica C.,das Neves, Amarith R.
, (2021/12/27)
This study reports the synthesis of novel neolignans-celecoxib hybrids and the evaluation of their biological activity. Analogs 8–13 (L13-L18) exhibited anti-inflammatory activity, inhibited glycoprotein expression (P-selectin) related to platelet activation, and were considered non– ulcerogenic in the animal model, even with the administration of 10 times higher than the dose used in reference therapy. In silico drug-likeness showed that the analogs are compliant with Lipinski's rule of five. A molecular docking study showed that the hybrids 8–13 (L13-L18) fitted similarly with celecoxib in the COX-2 active site. According to this data, it is possible to infer that extra hydrophobic interactions and the hydrogen interactions with the triazole core may improve the selectivity towards the COX-2 active site. Furthermore, the molecular docking study with P-selectin showed the binding affinity of the analogs in the active site, performing important interactions with amino acid residues such as Tyr 48. Whereas the P-selectin is a promising target to the design of new anti-inflammatory drugs with antithrombotic properties, a distinct butterfly-like structure of 1,4-diaryl-1,2,3-triazole neolignan-celecoxib hybrids synthesized in this work may be a safer alternative to the traditional COX-2 inhibitors.
Green bromination method
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Paragraph 0050-0052, (2021/06/13)
The invention discloses a green bromination method, and belongs to the field of green organic chemistry. Under the conditions of room temperature, opening and neutrality, reaction raw materials are aromatic hydrocarbon, olefin, alkyne, tryptamine, tryptophane and derivatives thereof with different functional groups, a bromine source is MBrx (M is Fe , Fe , Ce and the like, and x is 2-3), and the unique oxidant is H2O2. Brominated alkanes, alkenes, aromatic hydrocarbons, pyrrolo-indolines and furo-indolines and derivatives thereof can be produced. The bromination reaction is carried out by using easily available and cheap reagents (such as FeBr2, CeB3 and H2O2) in the market and the solvent, and the method has the characteristics of mild reaction conditions, wide substrate application range, simple steps, easiness in operation and no need of separation, is a green, environment-friendly and safe bromination reaction method, and has a good application prospect.
Bis-selenonium Cations as Bidentate Chalcogen Bond Donors in Catalysis
He, Xinxin,Wang, Xinyan,Tse, Ying-Lung Steve,Ke, Zhihai,Yeung, Ying-Yeung
, p. 12632 - 12642 (2021/10/21)
Lewis acids are frequently employed in catalysis but they often suffer from high moisture sensitivity. In many reactions, catalysts are deactivated because of the problem that strong Lewis acids also bond to the products. In this research, hydrolytically stable bidentate Lewis acid catalysts derived from selenonium dicationic centers have been developed. The bis-selenonium catalysts are employed in the activation of imine and carbonyl groups in various transformations with good yields and selectivity. Lewis acidity of the bis-selenonium salts was found to be stronger than that of the monoselenonium systems, attributed to the synergistic effect of the two cationic selenonium centers. In addition, the bis-selenonium catalysts are not inhibited by strong bases or moisture.
Evaluation of a Continuous-Flow Photo-Bromination Using N -Bromosuccinimide for Use in Chemical Manufacture
Waterford, Matthew,Saubern, Simon,Hornung, Christian H.
, p. 569 - 573 (2021/04/16)
A continuous-flow photo-bromination reaction on benzyl and phenyl groups was conducted using N-bromosuccinimide as the bromine source inside a preparatory-scale glass plate reactor. This flow reactor system was capable of independently controlling light intensity, wavelength, and reaction temperature, hence exerting an exceptional level of control over the reaction. A short optimisation study for the synthesis of 2-bromomethyl-4-trifluoromethoxyphenylboronic acid pinacol ester resulted in best conditions of 20°C and 10 min residence time using an LED (light-emitting diode) array at 405 nm and acetonitrile as the solvent. The present study evaluates the potential for this easy-to-handle bromination system to be scaled up for chemical manufacture inside a continuous-flow glass plate reactor. The combination with an in-line continuous flow liquid-liquid extraction and separation system, using a membrane separator, demonstrates the potential for continuous flow reaction with purification in an integrated multi-stage operation with minimal manual handling in between.
Hydrogen-Bond-Donor Solvents Enable Catalyst-Free (Radio)-Halogenation and Deuteration of Organoborons
Yang, Yi,Gao, Xinyan,Zeng, Xiaojun,Han, Junbin,Xu, Bo
supporting information, p. 1297 - 1300 (2020/12/23)
A hydrogen bond donor solvent assisted (radio)halogenation and deuteration of organoborons has been developed. The reactions exhibited high functional group tolerance and needed only an ambient atmosphere. Most importantly, compared to literature methods, our conditions are more consistent with the principals of green chemistry (e.g., metal-free, strong oxidant-free, more straightforward conditions).
Design of twisted conjugated molecular systems towards stable multi-colored electrochromic polymers
Gu, Hua,Hu, Faqi,Jian, Nannan,Lin, Kaiwen,Liu, Ximei,Lu, Baoyang,Wu, Tao,Xu, Jingkun,Xue, Yu
, (2020/08/13)
Promising advancement of conjugated polymers in electrochromic devices require to design high-performance electrochromic polymers with rich color conversion and long-term stability under cyclic electrical loads. Here we report a new strategy in developing multi-colored electrochromic polymers with good stability via twisted conjugated molecular engineering. A series of twisted hybrid precursors are synthesized by coupling ortho-alkylenedioxybenzenes with EDOT units, and their corresponding polymers are facilely electrosynthesized at relatively low polymerization potentials. The structure-property relationships of such ortho-alkylenedioxybenzene-EDOT hybrid precursors and polymers are systematically elucidated via DFT calculations, spectral, morphological, electrochemical and spectroelectrochemical analysis, etc. We demonstrate that the dihedral angle between ortho-alkylenedioxybenzenes and EDOT moieties can substantially affect the electrochemical and electrochromic properties of polymers. As the dihedral angle and electron cloud density increases, these hybrid polymers display distinct multiple color switching nature and good overall performance including high coloration efficiency (>200 cm2 C?1), decent optical contrast (>45percent), fast switching (1 s), and excellent switching stability (96percent of optical contrast after 3500 cycling) under cyclic electrical loads. With these findings, this work will provide novel insights for rational design of stable and highly efficient multi-colored electrochromic polymers.
Design, synthesis and antitrypanosomatid activities of 3,5-diaryl-isoxazole analogues based on neolignans veraguensin, grandisin and machilin G
Trefzger, Ozildéia S.,das Neves, Amarith R.,Barbosa, Natália V.,Carvalho, Diego B.,Pereira, Indiara C.,Perdomo, Renata T.,Matos, Maria F. C.,Yoshida, Nidia C.,Kato, Massuo J.,de Albuquerque, Sérgio,Arruda, Carla C. P.,Baroni, Adriano C. M.
, p. 313 - 324 (2018/11/30)
Using bioisosterism as a medicinal chemistry tool, 16 3,5-diaryl-isoxazole analogues of the tetrahydrofuran neolignans veraguensin, grandisin and machilin G were synthesized via 1,3-dipolar cycloaddition reactions, with yields from 43% to 90%. Antitrypanosomatid activities were evaluated against Trypanosoma cruzi, Leishmania (L.) amazonensis and Leishmania (V.) braziliensis. All compounds were selective for the Leishmania genus and inactive against T.?cruzi. Isoxazole analogues showed a standard activity on both promastigotes of L.?amazonensis and L.?braziliensis. The most active compounds were 15, 16 and 19 with IC50 values of 2.0, 3.3 and 9.5?μM against L.?amazonensis and IC50 values of 1.2, 2.1 and 6.4?μM on L.?braziliensis, respectively. All compounds were noncytotoxic, showing lower cytotoxicity (>250?μM) than pentamidine (78.9?μM). Regarding the structure–activity relationship (SAR), the methylenedioxy group was essential to antileishmanial activity against promastigotes. Replacement of the tetrahydrofuran nucleus by an isoxazole core improved the antileishmanial activity.
Applications of Selenonium Cations as Lewis Acids in Organocatalytic Reactions
He, Xinxin,Wang, Xinyan,Tse, Ying-Lung (Steve),Ke, Zhihai,Yeung, Ying-Yeung
supporting information, p. 12869 - 12873 (2018/09/14)
The use of trisubstituted selenonium salts as organic Lewis acids in electrophilic halogenation and aldol-type reactions has been developed. The substrate scope is broad. The reaction conditions are mild and compatible with various functionalities. This study opens a new avenue for the development of nonmetallic Lewis acid catalysis.
Environmentally benign indole-catalyzed position-selective halogenation of thioarenes and other aromatics
Shi, Yao,Ke, Zhihai,Yeung, Ying-Yeung
supporting information, p. 4448 - 4452 (2018/10/17)
Halogenated aromatic compounds are the cores of many pharmaceutical, agricultural and chemical products but they are commonly prepared using electrophilic halogenation reactions in non-green chlorinated solvents under harsh conditions. A separate problem happens in the aromatic halogenation of thioarenes because they readily undergo oxidative side-reactions. Herein we report an environmentally benign electrophilic bromination of aromatics using an indole-catalytic protocol, which is suitable for a wide range of substrates including thioarenes.
