135-68-2Relevant articles and documents
Suzuki coupling reaction catalyzed heterogeneously by Pd(salen)/ polyoxometalate compound: Another example for synergistic effect of organic/inorganic hybrid
Tong, Jinhui,Wang, Haiyan,Cai, Xiaodong,Zhang, Qianping,Ma, Hengchang,Lei, Ziqiang
, p. 95 - 100 (2014)
A hybrid compound consisting of palladium(salen) [salen = N,N′-bis(salicylidene)ethylenediamine] complex covalently linked to a lacunary Keggin-type polyoxometalate, K8[SiW11O 39](POM), was synthesized and characterized by FT-IR, elemental analysis, inductively coupled plasma and diffuse reflectance UV-visible spectroscopic methods. The hybrid, [Pd(salen)-POM], was investigated in the Suzuki cross-coupling in EtOH/H2O under mild reaction conditions. In comparison to the corresponding organic and inorganic moiety, the hybrid has shown greatly improved catalytic activity, and much higher yields toward coupling products were obtained with a low catalyst loading for various aryl halides, including unreactive and sterically hindered ones. The catalyst also exhibited prominent recyclable performance and no obvious loss of activity was observed after six consecutive runs.
Palladium nanoparticles immobilized on core-shell magnetic fibers as a highly efficient and recyclable heterogeneous catalyst for the reduction of 4-nitrophenol and Suzuki coupling reactions
Le, Xuanduong,Dong, Zhengping,Liu, Yansheng,Jin, Zhicheng,Huy, Thanh-Do,Le, Minhdong,Ma, Jiantai
, p. 19696 - 19706 (2014)
In this study, a novel core-shell magnetic fibrous nanocatalyst, Pd/Fe3O4@SiO2@KCC-1 with easily accessible active sites and a convenient recovery by applying an external magnetic field, was successfully developed. Fe3O4@SiO2@KCC-1 was functionalized with amino groups which act as robust anchors so that the palladium nanoparticles (Pd NPs) with an average diameter of about 4 nm were well-dispersed on the fibers of Fe3O4@SiO2@KCC-1 without obvious aggregation. The synthesized Pd/Fe3O4@SiO2@KCC-1 nanocatalyst exhibited excellent catalytic activity in the reduction of 4-nitrophenol by sodium borohydride, and the Suzuki cross coupling reactions of aryl chlorides with aryl boronic acids due to the easy accessibility of the active sites. Furthermore, the Pd/Fe3O4@SiO2@KCC-1 nanocatalyst was conveniently recovered by a magnet and could be reused for at least five cycles without significant loss in activity, thus confirming its good stability. Therefore, the abovementioned approach based on core-shell magnetic fibrous Fe3O4@SiO2@KCC-1 provided a useful platform for the fabrication of Pd NPs based catalysts with easy accessibility, superior activity and convenient recovery.
De novo design approaches targeting an envelope protein pocket to identify small molecules against dengue virus
Acosta Dávila, John Alejandro,Adler, Natalia S.,Aucar, Maria G.,Battini, Leandro,Bollini, Mariela,Cavasotto, Claudio N.,Cordo, Sandra M.,Fernández, Gabriela A.,Gamarnik, Andrea V.,García, Cybele C.,Gebhard, Leopoldo G.,Hernández de los Ríos, Alejandro,Leal, Emilse S.,Monge, María Eugenia,Morell, María L.,Videla, Mariela
supporting information, (2019/08/30)
Dengue fever is a mosquito-borne viral disease that has become a major public health concern worldwide. This disease presents with a wide range of clinical manifestations, from a mild cold-like illness to the more serious hemorrhagic dengue fever and dengue shock syndrome. Currently, neither an approved drug nor an effective vaccine for the treatment are available to fight the disease. The envelope protein (E) is a major component of the virion surface. This protein plays a key role during the viral entry process, constituting an attractive target for the development of antiviral drugs. The crystal structure of the E protein reveals the existence of a hydrophobic pocket occupied by the detergent n-octyl-β-d-glucoside (β-OG). This pocket lies at the hinge region between domains I and II and is important for the low pH-triggered conformational rearrangement required for the fusion of the virion with the host's cell. Aiming at the design of novel molecules which bind to E and act as virus entry inhibitors, we undertook a de novo design approach by “growing” molecules inside the hydrophobic site (β-OG). From more than 240000 small-molecules generated, the 2,4 pyrimidine scaffold was selected as the best candidate, from which one synthesized compound displayed micromolar activity. Molecular dynamics-based optimization was performed on this hit, and thirty derivatives were designed in silico, synthesized and evaluated on their capacity to inhibit dengue virus entry into the host cell. Four compounds were found to be potent antiviral compounds in the low-micromolar range. The assessment of drug-like physicochemical and in vitro pharmacokinetic properties revealed that compounds 3e and 3h presented acceptable solubility values and were stable in mouse plasma, simulated gastric fluid, simulated intestinal fluid, and phosphate buffered saline solution.
Diamines as interparticle linkers for silica-titania supported PdCu bimetallic nanoparticles in Chan-Lam and Suzuki cross-coupling reactions
Jamwal, Babita,Kaur, Manpreet,Sharma, Harsha,Khajuria, Chhavi,Paul, Satya,Clark
, p. 4919 - 4928 (2019/03/26)
A series of highly efficient amine functionalized SiO2-TiO2 supported bimetallic PdCu catalysts with varied metal composition have been synthesized. Ethane-1,2-diamine, butane-1,4-diamine and hexane-1,6-diamine were employed as interparticle linkers for amine functionalization of a SiO2-TiO2 support material so as to study the effect of pendant chain length on stabilization and immobilization of bimetallic nanoparticles. The shortest carbon chain length on the support provided the best results, which may be due to the trapping of metal nanoparticles more efficiently by the basic nitrogen sites. The catalytic activities of these materials were evaluated for C-N and C-C coupling reactions. The most active catalyst, Pd1Cu1@12DA-STS, was characterized by various techniques including SEM, HR-TEM, ICP-AES, XRD, FTIR, EDX, CHN analysis and TGA studies. Moreover, the synthesized catalyst was found to be recyclable for up to five runs without significant loss of activity.
