61439-53-0Relevant academic research and scientific papers
ROMP-Boranes as Moisture-Tolerant and Recyclable Lewis Acid Organocatalysts
Vidal, Fernando,McQuade, James,Lalancette, Roger,J?kle, Frieder
supporting information, p. 14427 - 14431 (2020/10/13)
Although widely used in catalysis, the multistep syntheses and high loadings typically employed are limiting broader implementation of highly active tailor-made arylborane Lewis acids and Lewis pairs. Attempts at developing recyclable systems have thus far met with limited success, as general and versatile platforms are yet to be developed. We demonstrate a novel approach that is based on the excellent control and functional group tolerance of ring-opening metathesis polymerization (ROMP). The ROMP of highly Lewis acidic borane-functionalized phenylnorbornenes afforded both a soluble linear copolymer and a cross-linked organogel. The polymers proved highly efficient as recyclable catalysts in the reductive N-alkylation of arylamines under mild conditions and at exceptionally low catalyst loadings. The modular design presented herein can be readily adapted to other finely tuned triarylboranes, enabling wide applications of ROMP-borane polymers as well-defined supported organocatalysts.
Development of an SNAr Reaction: A Practical and Scalable Strategy to Sequester and Remove HF
Blacker, A. John,Moran-Malagon, Gabriel,Powell, Lyn,Reynolds, William,Stones, Rebecca,Chapman, Michael R.
, (2018/09/27)
A simple and operationally practical method to sequester and remove fluoride generated through the SNAr reaction between amines and aryl fluorides is reported. Calcium propionate acts as an inexpensive and environmentally benign in situ scrubbe
Development of an SNAr Reaction: A Practical and Scalable Strategy to Sequester and Remove HF
Blacker, A. John,Moran-Malagon, Gabriel,Powell, Lyn,Reynolds, William,Stones, Rebecca,Chapman, Michael R.
, p. 1086 - 1091 (2018/09/29)
A simple and operationally practical method to sequester and remove fluoride generated through the SNAr reaction between amines and aryl fluorides is reported. Calcium propionate acts as an inexpensive and environmentally benign in situ scrubbe
Discovery of a benzenesulfonamide-based dual inhibitor of microsomal prostaglandin E2 synthase-1 and 5-lipoxygenase that favorably modulates lipid mediator biosynthesis in inflammation
Cheung, Sun-Yee,Werner, Markus,Esposito, Lucia,Troisi, Fabiana,Cantone, Vincenza,Liening, Stefanie,K?nig, Stefanie,Gerstmeier, Jana,Koeberle, Andreas,Bilancia, Rossella,Rizza, Roberta,Rossi, Antonietta,Roviezzo, Fiorentina,Temml, Veronika,Schuster, Daniela,Stuppner, Hermann,Schubert-Zsilavecz, Manfred,Werz, Oliver,Hanke, Thomas,Pace, Simona
supporting information, p. 815 - 830 (2018/07/29)
Leukotrienes (LTs) and prostaglandin (PG)E2, produced by 5-lipoxygenase (5-LO) and microsomal prostaglandin E2 synthase-1 (mPGES-1), respectively, are key players in inflammation, and pharmacological suppression of these lipid mediators (LM) represents a strategy to intervene with inflammatory disorders. Previous studies revealed that the benzenesulfonamide scaffold displays efficient 5-LO-inhibitory properties. Here, we structurally optimized benzenesulfonamides which led to an N-phenylbenzenesulfonamide derivative (compound 47) with potent inhibitory activities (IC50 = 2.3 and 0.4 μM for isolated 5-LO and 5-LO in intact cells, respectively). Compound 47 prevented the interaction of 5-LO with its activating protein (FLAP) at the nuclear envelope in transfected HEK293 cells as shown by in situ proximity ligation assay. Comprehensive assessment of the LM profile produced by human macrophages revealed the ability of 47 to selectively down-regulate pro-inflammatory LMs (i.e. LTs and PGE2) in M1 but to enhance the formation of pro-resolving LMs (i.e. resolvins and maresins) in M2 macrophages. Moreover, 47 strongly inhibited LT formation and cell infiltration in two in vivo models of acute inflammation (i.e., peritonitis and air pouch sterile inflammation in mice). Together, 47 represents a novel LT biosynthesis inhibitor with an attractive pharmacological profile as anti-inflammatory drug that also promotes the biosynthesis of pro-resolving LM.
O -Phenylenediamine: A privileged pharmacophore of ferrostatins for radical-trapping reactivity in blocking ferroptosis
Sheng, Xie-Huang,Cui, Cheng-Cheng,Shan, Chao,Li, Yu-Zhen,Sheng, Duo-Hong,Sun, Bin,Chen, De-Zhan
, p. 3952 - 3960 (2018/06/11)
Ferroptosis is a non-apoptotic, iron dependent form of regulated cell death that is characterized by the accumulation of lipid hydroperoxides. It has drawn considerable attention owing to its putative involvement in diverse neurodegenerative diseases. Ferrostatins are the first identified inhibitors of ferroptosis and they inhibit ferroptosis by efficiently scavenging free radicals in lipid bilayers. However, their further medicinal application has been limited due to the deficient knowledge of the lipid peroxyl radical-trapping mechanism. In this study, experimental and theoretical methods were performed to illustrate the possible lipid hydroperoxide inhibition mechanism of ferrostatins. The results show that an ortho-amine (-NH) moiety from ferrostatins can simultaneously interact with lipid radicals, and then form a planar seven-membered ring in the transition state, and finally present greater reactivity. NBO analysis shows that the formed planar seven-membered ring forces ortho-amines into better alignment with the aromatic π-system. It significantly increases the magnitudes of amine conjugation and improves spin delocalization in the transition state. Additionally, a classical H-bond type interaction was discovered between a radical and an o-NH group as another transition state stabilizing effect. This type of radical-trapping mechanism is novel and has not been found in diphenylamine or traditional polyphenol antioxidants. It can be said that o-phenylenediamine is a privileged pharmacophore for the design and development of ferroptosis inhibitors.
Alkene Metalates as Hydrogenation Catalysts
Büschelberger, Philipp,G?rtner, Dominik,Reyes-Rodriguez, Efrain,Kreyenschmidt, Friedrich,Koszinowski, Konrad,Jacobi von Wangelin, Axel,Wolf, Robert
, p. 3139 - 3151 (2017/03/13)
First-row transition-metal complexes hold great potential as catalysts for hydrogenations and related reductive reactions. Homo- and heteroleptic arene/alkene metalates(1?) (M=Co, Fe) are a structurally distinct catalyst class with good activities in hydrogenations of alkenes and alkynes. The first syntheses of the heteroleptic cobaltates [K([18]crown-6)][Co(η4-cod)(η2-styrene)2] (5) and [K([18]crown-6)][Co(η4-dct)(η4-cod)] (6), and the homoleptic complex [K(thf)2][Co(η4-dct)2] (7; dct=dibenzo[a,e]cyclooctatetraene, cod=1,5-cyclooctadiene), are reported. For comparison, two cyclopentadienylferrates(1?) were synthesized according to literature procedures. The isolated and fully characterized monoanionic complexes were competent precatalysts in alkene hydrogenations under mild conditions (2 bar H2, r.t., THF). Mechanistic studies by NMR spectroscopy, ESI mass spectrometry, and poisoning experiments documented the operation of a homogeneous mechanism, which was initiated by facile redox-neutral π-ligand exchange with the substrates followed by H2 activation. The substrate scope of the investigated precatalysts was also extended to polar substrates (ketones and imines).
CuI nanoparticles as recyclable heterogeneous catalysts for C-N bond formation reactions
Kumar, Manoranjan,Bhatt, Vinod,Nayal, Onkar S.,Sharma, Sushila,Kumar, Vishal,Thakur, Maheshwar S.,Kumar, Neeraj,Bal, Rajaram,Singh, Bikram,Sharma, Upendra
, p. 2857 - 2864 (2017/07/22)
Herein, copper iodide nanoparticles (NPs) are reported for the reductive amination of carbonyl compounds for the first time. The generated NPs were characterized by TEM, EDX, XRD and XPS analyses. The XRD patterns, XPS, and EDX analysis confirmed that the resulting NPs were CuI instead of Cu. The TEM images of CuI exhibited the size of monodispersed spherical NPs in the range of 4 ± 2 nm. These generated NPs can be used as versatile heterogeneous catalysts for important organic transformations. As a proof of concept, CuI NPs were successfully applied as heterogeneous catalysts for the synthesis of secondary amines, amides and triazoles. CuI NPs can be easily recovered and recycled up to six times.
Direct reductive amination using triethylsilane and catalytic bismuth(III) chloride
Matsumura, Takehiko,Nakada, Masahisa
, p. 1829 - 1834 (2014/03/21)
Direct reductive amination (DRA) using triethylsilane (TESH) and catalytic bismuth(III) chloride (BiCl3) is described for the first time. The use of TESH and BiCl3 provides easy handling, low cost, non-toxicity, and a mild Lewis acid activity, thereby meeting the demand for green and sustainable chemistry. The developed DRA is highly chemoselective and applicable to less-basic amines. The experimental results of this study revealed that the developed DRA could be catalyzed by BiCl3, which was gradually reduced to Bi(0) or bismuth with a low valency by TESH, but TESCl, Bi(0), and Bi(0) with TESCl catalyzed the DRA to some extent.
Reductive amination of acetals by anilines in the presence of triethylsilane and iodine
Zhang, Xue-Lin,Yu, Pan,Wu, Yong-Wei,Wu, Qin-Pei,Zhang, Qing-Shan
, p. 261 - 264 (2014/06/09)
A mild and efficient method for N-alkylation of aromatic amines with various acetals such as aryl, alkyl, cyclic and acyclic acetals was developed. A number of aromatic amines bearing electron-donating or electron-withdrawing substituents were directly alkylated by acetals with excellent yields. The method uses a catalytic amount of I2 and triethylsilane as the hydride source without a metal present. Monoalkylation with excellent chemoselectivity was observed.
Cu-catalyzed carbon-heteroatom coupling reactions under mild conditions promoted by resin-bound organic ionic bases
Huang, Yao-Bing,Yang, Chu-Ting,Yi, Jun,Deng, Xiao-Jian,Fu, Yao,Liu, Lei
experimental part, p. 800 - 810 (2011/04/22)
Resin-bound organic ionic bases (RBOIBs) were developed in which tetraalkyl-ammonium or phosphonium cations are covalently attached to solid resins. The application tests showed that the performance of the tetraalkyl-ammonium-type RBOIBs is slightly better than that of the corresponding Cs salts in Cu-catalyzed C-N cross-couplings, while the tetraalkylphosphonium-type RBOIBs are significantly better than all the inorganic bases. With these newly developed RBOIBs, room-temperature Cu-catalyzed C-Ncoupling with various nonactivated aryl iodides and even aryl bromides can be readily accomplished. Moreover, RBOIBs can be easily recycled and reused for a number of times without much drop of activity. The good performances of RBOIBs are proposed to arise from the relatively weak binding forces between the cationic polymer backbone and basic anions, as opposed to the strong metal-anion interactions in the inorganic bases. Further applications of RBOIBs in Ni-catalyzed Suzuki-type couplings at room temperature, Cu-catalyzed C-N couplings at -30 °C, a Pd-catalyzed Heck reaction at 60 °C, and Cu-catalyzed C-S couplings at room temperature demonstrate that RBOIBs are generally applicable bases with improved performance for many other types of organic transformations.
