90395-47-4Relevant academic research and scientific papers
Scaling up of continuous-flow, microwave-assisted, organic reactions by varying the size of Pd-functionalized catalytic monoliths
He, Ping,Haswell, Stephen J.,Fletcher, Paul D. I.,Kelly, Stephen M.,Mansfield, Andrew
, p. 1150 - 1157 (2011)
A product-scalable, catalytically mediated flow system has been developed to perform Suzuki-Miyaura reactions under a microwave heating regime, in which the volumetric throughput of a Pd-supported silica monolith can be used to increase the quantity of the product without changing the optimal operating conditions. Two silica monoliths (both 3 cm long), with comparable pore diameters and surface areas, were fabricated with diameters of 3.2 and 6.4 mm to give volumetric capacities of 0.205 and 0.790 mL, respectively. The two monoliths were functionalized with a loading of 4.5 wt % Pd and then sealed in heat-shrinkable Teflon tubing to form a monolithic flow reactor. The Pd-supported silica monolith flow reactor was then placed into the microwave cavity and connected to an HPLC pump and a backpressure regulator to minimize the formation of gas bubbles. The flow rate and microwave power were varied to optimize the reactant contact time and temperature, respectively. Under optimal reaction conditions the quantity of product could be increased from 31 mg per hour to 340 mg per hour simply by changing the volumetric capacity of the monolith.
PYRROLIDINE GLYCOSIDASE INHIBITORS
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Page/Page column 144, (2020/03/15)
Compounds of formula (I) wherein A, W, R3b, Z and p have the meaning according to the claims can be employed, inter alia, for the treatment of tauopathies and Alzheimer's disease.
Metal-Free Aryl Cross-Coupling Directed by Traceless Linkers
Haensch, Veit G.,Neuwirth, Toni,Steinmetzer, Johannes,Kloss, Florian,Beckert, Rainer,Gr?fe, Stefanie,Kupfer, Stephan,Hertweck, Christian
supporting information, p. 16068 - 16073 (2019/11/28)
The metal-free, highly selective synthesis of biaryls poses a major challenge in organic synthesis. The scope and mechanism of a promising new approach to (hetero)biaryls by the photochemical fusion of aryl substituents tethered to a traceless sulfonamide linker (photosplicing) are reported. Interrogating photosplicing with varying reaction conditions and comparison of diverse synthetic probes (40 examples, including a suite of heterocycles) showed that the reaction has a surprisingly broad scope and involves neither metals nor radicals. Quantum chemical calculations revealed that the C?C bond is formed by an intramolecular photochemical process that involves an excited singlet state and traversal of a five-membered transition state, and thus consistent ipso–ipso coupling results. These results demonstrate that photosplicing is a unique aryl cross-coupling method in the excited state that can be applied to synthesize a broad range of biaryls.
Pyridine sulfinates as general nucleophilic coupling partners in palladium-catalyzed cross-coupling reactions with aryl halides
Markovic, Tim,Rocke, Benjamin N.,Blakemore, David C.,Mascitti, Vincent,Willis, Michael C.
, p. 4437 - 4442 (2017/07/11)
Pyridine rings are ubiquitous in drug molecules; however, the pre-eminent reaction used to form carbon-carbon bonds in the pharmaceutical industry, the Suzuki-Miyaura cross-coupling reaction, often fails when applied to these structures. This phenomenon is most pronounced in 2-substituted pyridines, and results from the difficulty in preparing, the poor stability of, and low efficiency in reactions of pyridine-2-boronates. We demonstrate that by replacing these boronates with pyridine-2-sulfinates, a cross-coupling process of unrivalled scope and utility is realized. The corresponding 3-And 4-substituted pyridine variants are also efficient coupling partners. In addition, we apply these sulfinates in a library format to the preparation of medicinally relevant derivatives of the drugs varenicline (Chantix) and mepyramine (Anthisan).
Nickel-Catalyzed Decarbonylative Coupling of Aryl Esters and Arylboronic Acids
Laberge, Nicole A.,Love, Jennifer A.
, p. 5546 - 5553 (2015/09/01)
A variety of functionalized biaryls can be accessed by coupling aryl and heteroaryl esters with boronic acids in Suzuki-Miyaura-type decarbonylative cross-coupling catalyzed by an affordable catalyst system composed of Ni(cod)2 and PCy3. The methodology is tolerant of a variety of functional groups and presents an attractive alternative to the use of palladium catalysis currently used in industry to acquire such bis(hetero)aryls, but also reveals challenges associated with nickel catalysis of esters in cross-coupling chemistry.
Synthesis of heteroaryl compounds through cross-coupling reaction of aryl bromides or benzyl halides with thienyl and pyridyl aluminum reagents
Chen, Xu,Zhou, Lingmin,Li, Yimei,Xie, Tao,Zhou, Shuangliu
, p. 230 - 239 (2014/01/17)
An efficient method for synthesis of useful biaryl building blocks containing 2-thienyl, 3-thienyl, 2-pyridyl, and 3-pyridyl moieties was provided through cross-coupling reactions of aryl bromides or benzyl halides with heteroaryl aluminum reagents in the presence of Pd(OAc)2 and (o-tolyl)3P. The coupling reaction also worked efficiently with heteroaryl bromides affording series of heterobiaryl compounds. The reaction of phenylbromide with in situ prepared 3-pyridyl aluminum was demonstrated to afford the product 8a in high yield. Additionally, the catalytic system was also suited well for the coupling reaction of benzyl halides with pyridyl aluminum reagents to afford series of pyridyl-arylmethane.
Facile synthesis of 3-arylpyridine derivatives by palladacycle-catalyzed Stille cross-coupling reaction
Ma, Gaizhi,Leng, Yuting,Wu, Yusheng,Wu, Yangjie
, p. 902 - 909 (2013/07/25)
The Stille cross-coupling reaction of a variety of aryl halides (X=Cl, Br, I) with 3-alkylstannylpyridines highly catalyzed by cyclopalladated ferrocenylimine has been developed. This reaction allows formation of arylpyridine derivatives in moderate to excellent yields. Functional groups on aryl halides, such as amino, hydroxyl, keto, and aldehyde are tolerated and the reactions with arylbenzoxale substrates also proceed well.
Preparation of functionalized organoindium reagents by means of magnesium insertion into organic halides in the presence of InCl3 at room temperature
Bernhardt, Sebastian,Shen, Zhi-Liang,Knochel, Paul
supporting information, p. 828 - 833 (2013/02/23)
Magnesium, indium, palladium: An efficient one-pot procedure for the direct preparation of triorganoindium reagents from organic halides by means of magnesium insertion in the presence of InCl3 and LiCl is reported (see scheme). The organoindium reagents are obtained in good yields from functionalized aryl, heteroaryl, and alkyl bromides and benzyl chlorides at 25 °C in THF within 4h. Moreover, the resulting organoindium reagents could be efficiently used as reagents in Pd-catalyzed cross-coupling reactions with a wide functional group tolerance. Copyright
Discovery and mechanism study of SIRT1 activators that promote the deacetylation of fluorophore-labeled substrate
Wu, Jiahui,Zhang, Dengyou,Chen, Lei,Li, Jianneng,Wang, Jianling,Ning, Chengqing,Yu, Niefang,Zhao, Fei,Chen, Dongying,Chen, Xiaoyan,Chen, Kaixian,Jiang, Hualiang,Liu, Hong,Liu, Dongxiang
, p. 761 - 780 (2013/04/10)
SIRT1 is an NAD+-dependent deacetylase, whose activators have potential therapeutic applications in age-related diseases. Here we report a new class of SIRT1 activators. The activation is dependent on the fluorophore labeled to the substrate. To elucidate the activation mechanism, we solved the crystal structure of SIRT3/ac-RHKKac-AMC complex. The structure revealed that the fluorophore blocked the H-bond formation and created a cavity between the substrate and the Rossmann fold. We built the SIRT1/ac-RHKK ac-AMC complex model based on the crystal structure. Km and Kd determinations demonstrated that the fluorophore decreased the peptide binding affinity. The binding modes of SIRT1 activators indicated that a portion of the activators interacts with the fluorophore through π-stacking, while the other portion inserts into the cavity or interacts with the Rossmann fold, thus increasing the substrate affinity. Our study provides new insights into the mechanism of SIRT1 activation and may aid the design of novel SIRT1 activators.
Room-temperature Suzuki-Miyaura coupling of heteroaryl chlorides and tosylates
Yang, Junfeng,Liu, Sijia,Zheng, Jian-Feng,Zhou, Jianrong
supporting information, p. 6248 - 6259,12 (2020/09/16)
Suzuki-Miyaura coupling of heteroaryls is an important method for the preparation of compound libraries for medicinal chemistry and materials research. Although many catalysts have been developed, none of them have been generally applicable to the coupling reactions of heteroaryl chlorides and tosylates at room temperature. We discovered that a catalyst combination of Pd(OAc)2 and XPhos (2-dicyclohexylphosphanyl-2',4',6'- triisopropylbiphenyl) could efficiently catalyze these couplings. Besides the choice of catalyst, the use of hydroxide bases in an aqueous alcoholic solvent was essential for fast couplings. These conditions promoted fast release of active catalyst (XPhos)Pd0, and accelerated the transmetalation in the catalytic cycle. Most of the major families of heteroaryl chlorides (31 examples) and tosylates (17 examples) reached full conversion within minutes to hours at room temperature. The method could be easily scaled up for gram-scale synthesis. Furthermore, we examined the relative reactivity of coupling partners in whole reactions. Electron-rich heteroaryl chlorides and tosylates reacted more slowly than electron-deficient ones, in the order of indole, pyrrole furan, thiophene > pyridine. Similarly, electron-deficient arylboronic acids were less reactive than electron-neutral and electron-rich ones. The reactivity trends from this study can help to choose appropriate coupling partners for Suzuki reactions.
