21370-57-0Relevant academic research and scientific papers
Heck Reaction over Pd-Loaded ETS-10 Molecular Sieve
Waghmode, Suresh Babasaheb,Wagholikar, Smita Girish,Sivasanker, Subramanian
, p. 1989 - 1992 (2003)
ETS-10 molecular sieve has been used as a catalyst in the shape-selective photo catalytic decomposition of aromatic molecules, Aldol-type condensations, aniline oxidation, acylation reactions, and alcohol dehydrogenation. The carbon-carbon coupling of different aryl halides with ethyl acrylate over Pd-loaded ETS-10 was presented. The influences of the Pd content, nature of the base and reactivity of the different substrates and reactants on the coupling reaction were presented. The catalyst exhibited high activity and selectivity towards the carbon-carbon coupling of aryl halides with olefins, even at low concentrations of palladium (0.009 to 1.4 mole % with respect to the substrate). In the case of the coupling of ethyl acrylate with iodobenzene, 96% conversion of iodobenzene with > 98% selectivity could be obtained within 1 hr over a 0.2 wt % Pd-loaded catalyst. The catalyst activated aryl bromide and chloride substrates, and was heterogeneous. Aryl bromide, chloride and their derivatives exhibited moderate activity with ethyl acrylates. Organic bases led to higher catalytic activity than inorganic bases. The catalysts could be reused and reactivated by washing with a moderate decrease in activity. The substrate reactivity increased with electron-withdrawing substituents.
Synthesis, characterization, photophysical properties, and catalytic activity of an SCS bis(N-heterocyclic thione) (SCS-NHT) Pd pincer complex
Tyson, Ginger E.,Tokmic, Kenan,Oian, Casey S.,Rabinovich, Daniel,Valle, Henry U.,Hollis, T. Keith,Kelly, John T.,Cuellar, Kristina A.,McNamara, Louis E.,Hammer, Nathan I.,Webster, Charles Edwin,Oliver, Allen G.,Zhang, Min
, p. 14475 - 14482 (2015)
Treatment of 1,3-bis(3′-butylimidazolyl-1′-yl)benzene diiodide with elemental sulfur in the presence of a base produced a bis(N-heterocyclic thione) (NHT) pincer ligand precursor. Its reaction with PdCl2(CH3CN)2 produced chloro[1,3-bis(3′-butylimidazole-2′-thione-κ-S)benzene-κ-C]palladium(ii), a 6,6-fused ring SCS-NHT palladium pincer complex. This air stable compound is, to our knowledge, the first SCS pincer complex that utilizes N-heterocyclic thione (NHT) donor groups. The molecular structures of the ligand precursor and the palladium complex were determined by X-ray crystallography and computational studies provided insight into the interconversion between its rac and meso conformations. The photophysical properties of the complex were established, and its catalytic activity in Suzuki, Heck, and Sonogashira cross-coupling reactions was evaluated.
Discovery of a novel inhibitor of nitric oxide production with potential therapeutic effect on acute inflammation
Zhu, Long-Qing,Fan, Xiao-Hong,Li, Jun-Fang,Chen, Jin-Hong,Liang, Yan,Hu, Xiao-Ling,Ma, Shu-Meng,Hao, Xiang-Yong,Shi, Tao,Wang, Zhen
supporting information, (2021/05/26)
Inflammation as a host's excessive immune response to stimulation, is involved in the development of numerous diseases. To discover novel anti-inflammatory agents and based on our previous synthetic work on marine natural product Chrysamide B, it and a series of derivatives were synthesized and evaluated for their anti-inflammatory activity on inhibition of LPS-induced NO production. Then the preliminary structure–activity relationships were conducted. Among them, Chrysamide B is the most potent anti-inflammatory agent with low cytotoxicity and strong inhibition on the production of NO (IC50 = 0.010 μM) and the activity of iNOS (IC50 = 0.082 μM) in LPS-stimulated RAW 264.7 cells. Primary studies suggested that the mechanism of action may be that it interfered the formation of active dimeric iNOS but not affected transcription and translation. Furthermore, its good performance of anti-inflammatory effect on LPS-induced multiple inflammatory cytokines production, carrageenan-induced paw edema, and endotoxin-induced septic mice, was observed. We believe that these findings would provide an idea for the further modification and research of these analogs in the future.
Oxiranyl remote anions from epoxy cinnamates and their application towards the synthesis of α,β-epoxy-γ-butyrolactones
Sermmai, Patpanat,Ruangsupapichat, Nopporn,Thongpanchang, Tienthong
supporting information, (2020/11/19)
A series of α,β-epoxy-γ-butyrolactones were synthesized in moderate yields via oxiranyl remote anions derived from epoxy cinnamate esters. The key synthetic step involved deprotonation of the β-position of α,β-epoxy cinnamate derivatives where the generated β-anion was stabilized by remote chelation from an ester group. The substitution reaction of the anion with a variety of ketones, followed by cyclization, readily furnished the desired substituted α,β-epoxy-γ-butyrolactones.
Copper-Photocatalyzed Contra-Thermodynamic Isomerization of Polarized Alkenes
Bouillon, Jean-Philippe,Brégent, Thibaud,Poisson, Thomas
supporting information, p. 7688 - 7693 (2020/10/09)
The contra-thermodynamic isomerization of α- and β-substituted cinnamate derivatives catalyzed by the Cu(OAc)2/rac-BINAP complex under blue light irradiation is reported. The use of an oxazolidinone template, which favored the complexation of the copper catalyst to the substrate, allowed the E → Z isomerization of the catalytically formed chromophore under simple and robust reaction conditions in good to excellent ratios. The mechanism of this process based on the transient formation of a chromophore was also studied.
Recyclable Pd ionic catalyst coated on cordierite monolith for high TOF Heck coupling reaction
Bhat, Shrikanth K,Prasad, Jagadeesh D,Hegde
, (2019/02/19)
Abstract : Pd 2 + ionic catalyst, Ti 0.97Pd 0.03O 1.97 was coated over cordierite monolith by solution combustion method. The catalyst coated on the cordierite is nano-crystalline as seen from XRD studies. Coated catalyst was used for Heck coupling reactions with different substrates of aryl halides and olefins. Thus handling nano-crystalline catalyst powder is avoided by fixing it on a solid catalyst cartridge. Heck coupled products were characterized using 1H NMR, 13C NMR, Mass and FTIR spectroscopy. This catalyst showed high selectivity towards Heck coupling reaction. Turnover frequencies (TOF) for each of the reactions were found to be very high. The catalyst was recycled up to 7 times with total TOF 3017 h - 1, which is found to be a new green technique in the Heck coupling reaction. Graphical abstract: Ti 0.97Pd 0.03O 1.97 catalyst is coated on cordierite monolith honeycomb (HC) by solution combustion method and it is used in the Heck coupling reaction. Reactions are done in a specially designed flask. Catalyst is recycled for 7 times. The total turnover frequency (TOF) after 7 cycles was 3017 h - 1. [Figure not available: see fulltext.].
Synthesis and discovery of 18β-glycyrrhetinic acid derivatives inhibiting cancer stem cell properties in ovarian cancer cells
Li, Xiaojing,Liu, Yihua,Wang, Na,Liu, Yuyu,Wang, Shuai,Wang, Hongmin,Li, Aihua,Ren, Shaoda
, p. 27294 - 27304 (2019/09/12)
Despite advances in ovarian cancer treatment, the five-year overall survival rate is less than 30% with the presence of cancer stem cells (CSCs). To develop CSC-targeting therapy, a series of 18β-glycyrrhetinic acid (GA) derivatives containing cinnamamide moiety have been designed, synthesized, and screened for their antiproliferative activity in SKOV3 and OVCAR3 cells. Most of the compounds exhibited stronger antiproliferative activity than GA, and compound 7c was the most active one. Further biological studies showed that compound 7c could induce apoptosis and suppress migration. In addition, compound 7c could not only observably decrease the colony formation and sphere formation ability, but also significantly reduce the CD44+, CD133+, and ALDH+ subpopulation in SKOV3 and OVCAR3 cells. In conclusion, these results indicate that compound 7c is a promising anti-CSC agent for further anti-ovarian cancer studies.
Synthesis and structural characterization for novel mixed-donor ligand palladium (II) based on graphene and oxime: its application as a highly stable and efficient recyclable catalyst
Ashiri, Samira,Mehdipour, Ebrahim
, p. 2383 - 2393 (2018/08/28)
In this article, the palladium (II) mixed-ligand complex synthesized with reduced graphene oxides containing tetraethoxysilane and menthone oxime was used as an efficient solid catalyst for the Heck coupling reaction. To maintain stability and catalytic activity in the C–C bond reaction, graphene was considered due to the available surface as the solid support. Then, the structure of new heterogeneous catalyst was investigated by FT-IR, UV–Vis DRS, FE-SEM, EDX, AFM, XRD, ICP-OES, Raman, and TGA. The newly synthesized nanocatalyst have beneficial properties, including product’s easy separation, the shorter time to react, purity products (yield 79–99%), and easier work-up procedure. Furthermore, the catalyst was reused six times without significant degradation in catalytic activity and performance.
Preparation of a novel palladium catalytic hydrogel based on graphene oxide/chitosan NPs and cellulose nanowhiskers
Ashiri, Samira,Mehdipour, Ebrahim
supporting information, p. 32877 - 32885 (2018/10/15)
The present paper focuses on the synthesis of a novel hydrogel support by combining polysaccharides (chitosan NPs and dialdehyde cellulose nanowhiskers) and graphene oxide nanosheets to obtain a biocompatible material for catalytic applications. The hydrogel was synthesized via green chemistry processes and used as a support to prepare Pd nanoparticles. Finally, the hydrogel@Pd NPs was employed as the catalyst in the Mizoroki-Heck reaction to generate new C-C bonds. SEM analysis indicated that the hydrogel has macroporous morphology, which is in good correlation with its high crosslinking degree. The as-synthesized nanocomposite hydrogel exhibits beneficial properties such as ease of separation and excellent recyclability for at least six cycles without considerable loss in its activity. The yields of the products range from 81% to 98%. Additionally, this study provides the possibility to perform the Mizoroki-Heck reaction with aryl chloride in the presence of the as-prepared catalyst.
Control of Chemo-, Regio-, and Enantioselectivity in Copper Hydride Reductions of Morita-Baylis-Hillman Adducts
Linstadt, Roscoe T. H.,Peterson, Carl. A.,Jette, Carina I.,Boskovic, Zarko V.,Lipshutz, Bruce H.
supporting information, p. 328 - 331 (2017/04/21)
Nonracemically ligated copper hydride can be used to effect tandem SN2′/1,2-reductions of racemic Morita-Baylis-Hillman (MBH) acetates to access enantioenriched chiral allylic alcohols with defined olefin geometry. MBH esters, including those w
