- Scalable Negishi Coupling between Organozinc Compounds and (Hetero)Aryl Bromides under Aerobic Conditions when using Bulk Water or Deep Eutectic Solvents with no Additional Ligands
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Pd-catalyzed Negishi cross-coupling reactions between organozinc compounds and (hetero)aryl bromides have been reported when using bulk water as the reaction medium in the presence of NaCl or the biodegradable choline chloride/urea eutectic mixture. Both C(sp3)-C(sp2) and C(sp2)-C(sp2) couplings have been found to proceed smoothly, with high chemoselectivity, under mild conditions (room temperature or 60 °C) in air, and in competition with protonolysis. Additional benefits include very short reaction times (20 s), good to excellent yields (up to 98 %), wide substrate scope, and the tolerance of a variety of functional groups. The proposed novel protocol is scalable, and the practicability of the method is further highlighted by an easy recycling of both the catalyst and the eutectic mixture or water.
- Dilauro, Giuseppe,Azzollini, Claudia S.,Vitale, Paola,Salomone, Antonio,Perna, Filippo M.,Capriati, Vito
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supporting information
p. 10632 - 10636
(2021/04/09)
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- Preparation method of substituted butyrate derivatives
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The invention discloses a preparation method of substituted butyrate derivatives. The method specifically comprises the following steps: by taking compounds shown in a formula 1, a formula 2 and a formula 3 as raw materials, carrying out an illumination reaction process in the presence of a photocatalyst and a hydrogen transfer catalyst to obtain a target compound shown in a formula I through one-step reaction. The invention discloses a free radical-mediated olefin bifunctional reaction without a cyclopropanation intermediate. The reaction can realize a product which can be obtained through cyclopropanation and cyclopropane ring opening processes traditionally in one step. Meanwhile, the preparation method of the compound is simple, uses cheap and easily available compounds as raw materials, and has the beneficial effects of one-step synthesis, mild reaction conditions, fast reaction, low cost, less generated waste, simple and safe operation, high atom economy, high selectivity, extremely wide substrate applicability, high yield and the like.
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Paragraph 0093-0096
(2020/07/15)
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- Radical-Mediated Strategies for the Functionalization of Alkenes with Diazo Compounds
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One of the most common reactions of diazo compounds with alkenes is cyclopropanation, which occurs through metal carbene or free carbene intermediates. Alternative functionalization of alkenes with diazo compounds is limited, and a methodology for the addition of the elements of Z-CHR2 (with Z = H or heteroatom, and CHR2 originates from N2 CR2) across a carbon-carbon double bond has not been reported. Here we report a novel reaction of diazo compounds utilizing a radical-mediated addition strategy to achieve difunctionalization of diverse alkenes. Diazo compounds are transformed to carbon radicals with a photocatalyst or an iron catalyst through PCET processes. The carbon radical selectively adds to diverse alkenes, delivering new carbon radical species, and then forms products through hydroalkylation by thiol-assisted hydrogen atom transfer (HAT), or forms azidoalkylation products through an iron catalytic cycle. These two processes are highly complementary, proceed under mild reaction conditions, and show high functional group tolerance. Furthermore, both transformations are successfully performed on a gram-scale, and diverse γ-amino esters, γ-amino alcohols, and complex spirolactams are easily prepared with commercially available reagents. Mechanistic studies reveal the plausible pathways that link the two processes and explain the unique advantages of each.
- Su, Yong-Liang,Liu, Geng-Xin,Liu, Jun-Wen,Tram, Linh,Qiu, Huang,Doyle, Michael P.
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supporting information
p. 13846 - 13855
(2020/09/21)
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- Computer-Assisted Discovery and Structural Optimization of a Novel Retinoid X Receptor Agonist Chemotype
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As universal heterodimer partners of many nuclear receptors, the retinoid X receptors (RXRs) constitute key transcription factors. They regulate cell proliferation, differentiation, inflammation, and metabolic homeostasis and have recently been proposed as potential drug targets for neurodegenerative and inflammatory diseases. Owing to the hydrophobic nature of RXR ligand binding sites, available synthetic RXR ligands are lipophilic, and their structural diversity is limited. Here, we disclose the computer-assisted discovery of a novel RXR agonist chemotype and its systematic optimization toward potent RXR modulators. We have developed a nanomolar RXR agonist with high selectivity among nuclear receptors and superior physicochemical properties compared to classical rexinoids that appears suitable for in vivo applications and as lead for future RXR-targeting medicinal chemistry.
- Heitel, Pascal,Gellrich, Leonie,Kalinowsky, Lena,Heering, Jan,Kaiser, Astrid,Ohrndorf, Julia,Proschak, Ewgenij,Merk, Daniel
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p. 203 - 208
(2019/01/25)
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- Design, synthesis, and structure-activity relationships of a series of 4-benzyl-5-isopropyl-1H-pyrazol-3-yl β-d-glycopyranosides substituted with novel hydrophilic groups as highly potent inhibitors of sodium glucose co-transporter 1 (SGLT1)
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Sodium glucose co-transporter 1 (SGLT1) plays a dominant role in the absorption of glucose in the gut and is considered a promising target in the development of therapeutic options for postprandial hyperglycemia. Previously, we reported potent and selective SGLT1 inhibitors 1 and 2 showing efficacy in oral carbohydrate tolerance tests in diabetic rat models. In a pharmacokinetic (PK) study of 2, excessive systemic exposure to metabolites of 2 was observed, presumably due to the high permeability of its aglycone (2a). To further improve SGLT1 inhibitory activity and reduce aglycone permeability, a series of 4-benzyl-5-isopropyl-1H-pyrazol-3-yl β-d-glycopyranoside derivatives bearing novel hydrophilic substitution groups on the phenyl ring were synthesized and their inhibitory activity toward SGLTs was evaluated. Optimized compound 14c showed an improved profile satisfying both higher activity and lower permeability of its aglycone (22f) compared with initial leads 1 and 2. Moreover, the superior efficacy of 14c in various carbohydrate tolerance tests in diabetic rat models was confirmed compared with acarbose, an α-glucosidase inhibitor (α-GI) widely used in the clinic.
- Fushimi, Nobuhiko,Teranishi, Hirotaka,Shimizu, Kazuo,Yonekubo, Shigeru,Ohno, Kohsuke,Miyagi, Takashi,Itoh, Fumiaki,Shibazaki, Toshihide,Tomae, Masaki,Ishikawa-Takemura, Yukiko,Nakabayashi, Takeshi,Kamada, Noboru,Yamauchi, Yuji,Kobayashi, Susumu,Isaji, Masayuki
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p. 748 - 765
(2013/02/25)
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- Design and synthesis of novel lactate dehydrogenase a inhibitors by fragment-based lead generation
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Lactate dehydrogenase A (LDHA) catalyzes the conversion of pyruvate to lactate, utilizing NADH as a cofactor. It has been identified as a potential therapeutic target in the area of cancer metabolism. In this manuscript we report our progress using fragment-based lead generation (FBLG), assisted by X-ray crystallography to develop small molecule LDHA inhibitors. Fragment hits were identified through NMR and SPR screening and optimized into lead compounds with nanomolar binding affinities via fragment linking. Also reported is their modification into cellular active compounds suitable for target validation work.
- Ward, Richard A.,Brassington, Claire,Breeze, Alexander L.,Caputo, Alessandro,Critchlow, Susan,Davies, Gareth,Goodwin, Louise,Hassall, Giles,Greenwood, Ryan,Holdgate, Geoffrey A.,Mrosek, Michael,Norman, Richard A.,Pearson, Stuart,Tart, Jonathan,Tucker, Julie A.,Vogtherr, Martin,Whittaker, David,Wingfield, Jonathan,Winter, Jon,Hudson, Kevin
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p. 3285 - 3306
(2012/06/01)
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- One-pot Negishi cross-coupling reactions of in situ generated zinc reagents with aryl chlorides, bromides, and triflates
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(Chemical Equation Presented) In situ generated aryl, heteroaryl, alkyl, or benzylic poly-functional zinc reagents obtained by the addition of zinc and LiCl to the corresponding organic iodides undergo smooth Pd(0)-catalyzed cross-coupling reactions with
- Sase, Shohei,Jaric, Milica,Metzger, Albrecht,Malakhov, Vladimir,Knochel, Paul
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supporting information; experimental part
p. 7380 - 7382
(2009/05/07)
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- NAPHTHALENE AMIDES HAVING LEUKOTRIENE-ANTAGONISTIC ACTION
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Naphthalene amides of formula (I) wherein the substituent containing A is bound to the 6- or 7- position of the 2-naphthol system; the substituent containing B is bound to the benzene ring at any free position; R is hydrogen or methyl; R is hydrogen, fluorine, chlorine or -OCH3, which is bound to the naphthalene system at any positions except the 2- and the one occupied by the other substituent; R is hydrogen, fluorine, chlorine or bromine; A- is -CO-NR- or -NR-CO- group, wherein R is hydrogen or methyl; B is a 5-tetrazolyl or -COOR group, wherein R is hydrogen, a (C1-C4)-alkyl or a phenylalkyl group of less than 10 carbon atoms; m is 0 or 1; n and p are integers from 0 to 6, with the proviso that n + p is less or equal to 6; as well as the solvates and pharmaceutically acceptable salts thereof, have leukotriene antagonistic action.
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