2173-69-5Relevant articles and documents
Dienolates of Cycloalkenones and α,β-Unsaturated Esters Form Diels–Alder Adducts by a Michael/Michael-Tandem Reaction Rather Than in One Step
Loesche, Ann-Christine,Brückner, Reinhard
, p. 562 - 573 (2019)
α,β-Unsaturated esters and lithium 1,3-dien-2-olates are known to furnish bicyclic lithium enolates by anionic Diels–Alder reactions. However, in principle, the respective products might form not only in a single step but also in two consecutive – or “tandem” – Michael additions, the first of which occurs intermolecularly, the second intramolecularly. Three cyclic lithium dienolates and four esters with a stereogenic Cα=Cβ bond reacted to give Diels–Alder adducts (10 times) or failed to react (2 times). Seven of the reactive combinations furnished adducts wherein the configuration of the former ester moiety had in part inverted. This precludes concerted pathways as their origins. This was a surprise since donors at C-2 of the 1,3-diene accelerate normal electron-demand Diels–Alder reactions in the order alkyl ⊕O? being a far better donor still, it is not obvious why the mechanism is non-concerted rather than concerted (and still more asynchronous).
Discovery of Salidroside-Derivated Glycoside Analogues as Novel Angiogenesis Agents to Treat Diabetic Hind Limb Ischemia
Liu, Caiping,Han, Jingxuan,Marcelina, Olivia,Nugrahaningrum, Dyah Ari,Huang, Song,Zou, Meijuan,Wang, Guixue,Miyagishi, Makoto,He, Yun,Wu, Shourong,Kasim, Vivi
, p. 135 - 162 (2022/01/14)
Therapeutic angiogenesis is a potential therapeutic strategy for hind limb ischemia (HLI); however, currently, there are no small-molecule drugs capable of inducing it at the clinical level. Activating the hypoxia-inducible factor-1 (HIF-1) pathway in skeletal muscle induces the secretion of angiogenic factors and thus is an attractive therapeutic angiogenesis strategy. Using salidroside, a natural glycosidic compound as a lead, we performed a structure-activity relationship (SAR) study for developing a more effective and druggable angiogenesis agent. We found a novel glycoside scaffold compound (C-30) with better efficacy than salidroside in enhancing the accumulation of the HIF-1α protein and stimulating the paracrine functions of skeletal muscle cells. This in turn significantly increased the angiogenic potential of vascular endothelial and smooth muscle cells and, subsequently, induced the formation of mature, functional blood vessels in diabetic and nondiabetic HLI mice. Together, this study offers a novel, promising small-molecule-based therapeutic strategy for treating HLI.
Structure-Guided Optimization of Dipeptidyl Inhibitors of Norovirus 3CL Protease
Rathnayake, Athri D.,Kim, Yunjeong,Dampalla, Chamandi S.,Nguyen, Harry Nhat,Jesri, Abdul-Rahman M.,Kashipathy, Maithri M.,Lushington, Gerald H.,Battaile, Kevin P.,Lovell, Scott,Chang, Kyeong-Ok,Groutas, William C.
, p. 11945 - 11963 (2020/11/26)
Acute gastroenteritis caused by noroviruses has a major impact on public health worldwide in terms of morbidity, mortality, and economic burden. The disease impacts most severely immunocompromised patients, the elderly, and children. The current lack of approved vaccines and small-molecule therapeutics for the treatment and prophylaxis of norovirus infections underscores the need for the development of norovirus-specific drugs. The studies described herein entail the use of the gem-dimethyl moiety as a means of improving the pharmacological activity and physicochemical properties of a dipeptidyl series of transition state inhibitors of norovirus 3CL protease, an enzyme essential for viral replication. Several compounds were found to be potent inhibitors of the enzyme in biochemical and cell-based assays. The pharmacological activity and cellular permeability of the inhibitors were found to be sensitive to the location of the gem-dimethyl group.
Expeditious Total Synthesis of Hemiasterlin through a Convergent Multicomponent Strategy and Its Use in Targeted Cancer Therapeutics
Carroll, Jason S.,Charoenpattarapreeda, Jiraborrirak,Spring, David R.,Walsh, Stephen J.
supporting information, p. 23045 - 23050 (2020/11/11)
Hemiasterlin is an antimitotic marine natural product with reported sub-nanomolar potency against several cancer cell lines. Herein, we describe an expeditious total synthesis of hemiasterlin featuring a four-component Ugi reaction (Ugi-4CR) as the key st
Oxidative and Redox-Neutral Approaches to Symmetrical Diamines and Diols by Single Electron Transfer/Hydrogen Atom Transfer Synergistic Catalysis
Fujita, Masashi,Kobayashi, Fumihisa,Ide, Takafumi,Egami, Hiromichi,Hamashima, Yoshitaka
supporting information, p. 7151 - 7155 (2020/12/01)
Homocoupling reactions of benzylamines and benzyl alcohols were examined under synergistic catalysis conditions with a photoredox catalyst and thiobenzoic acid as a hydrogen atom abstractor. When pivalaldehyde was used as an electron acceptor, oxidative dimerization proceeded selectively, whereas the use of benzaldehydes or iminium ions as electron acceptors resulted in redox-neutral coupling. These reactions afforded symmetrical 1,2-diamines and 1,2-diols in good yields.
Aerobic C-C and C-O bond formation reactions mediated by high-valent nickel species
Gómez, Laura,Mirica, Liviu M.,Planas, Oriol,Rath, Nigam P.,Ribas, Xavi,Smith, Sofia M.
, p. 10366 - 10372 (2019/11/20)
Nickel complexes have been widely employed as catalysts in C-C and C-heteroatom bond formation reactions. While Ni(0), Ni(i), and Ni(ii) intermediates are most relevant in these transformations, recently Ni(iii) and Ni(iv) species have also been proposed to play a role in catalysis. Reported herein is the synthesis, detailed characterization, and reactivity of a series of Ni(ii) and Ni(iii) metallacycle complexes stabilized by tetradentate pyridinophane ligands with various N-substituents. Interestingly, while the oxidation of the Ni(ii) complexes with various other oxidants led to exclusive C-C bond formation in very good yields, the use of O2 or H2O2 as oxidants led to formation of appreciable amounts of C-O bond formation products, especially for the Ni(ii) complex supported by an asymmetric pyridinophane ligand containing one tosyl N-substituent. Moreover, cryo-ESI-MS studies support the formation of several high-valent Ni species as key intermediates in this uncommon Ni-mediated oxygenase-type chemistry.
Donor–Acceptor Complex Enables Alkoxyl Radical Generation for Metal-Free C(sp3)–C(sp3) Cleavage and Allylation/Alkenylation
Zhang, Jing,Li, Yang,Xu, Ruoyu,Chen, Yiyun
supporting information, p. 12619 - 12623 (2017/09/11)
The alkoxyl radical is an essential and prevalent reactive intermediate for chemical and biological studies. Here we report the first donor–acceptor complex-enabled alkoxyl radical generation under metal-free reaction conditions induced by visible light. Hantzsch ester forms the key donor–acceptor complex with N-alkoxyl derivatives, which is elucidated by a series of spectrometry and mechanistic experiments. Selective C(sp3)-C(sp3) bond cleavage and allylation/alkenylation is demonstrated for the first time using this photocatalyst-free approach with linear primary, secondary, and tertiary alkoxyl radicals.
Br?nsted Acid-Catalyzed Intramolecular Hydroarylation of β-Benzylstyrenes
Cai, Xiao,Keshavarz, Amir,Omaque, Justin D.,Stokes, Benjamin J.
supporting information, p. 2626 - 2629 (2017/05/24)
Using triphenylmethylium tetrakis(pentafluorophenyl)borate as a convenient Br?nsted acid precatalyst, β-(α,α-dimethylbenzyl)styrenes are shown to cyclize efficiently to afford a variety of new indanes that possess a benzylic quaternary center. The geminal dimethyl-containing quaternary center is proposed to be necessary to arm the substrate for cyclization through steric biasing.
Design of Potent and Druglike Nonphenolic Inhibitors for Catechol O-Methyltransferase Derived from a Fragment Screening Approach Targeting the S-Adenosyl- l -methionine Pocket
Lerner, Christian,Jakob-Roetne, Roland,Buettelmann, Bernd,Ehler, Andreas,Rudolph, Markus,Sarmiento, Rosa María Rodríguez
, p. 10163 - 10175 (2016/12/07)
A fragment screening approach designed to target specifically the S-adenosyl-l-methionine pocket of catechol O-methyl transferase allowed the identification of structurally related fragments of high ligand efficiency and with activity on the described orthogonal assays. By use of a reliable enzymatic assay together with X-ray crystallography as guidance, a series of fragment modifications revealed an SAR and, after several expansions, potent lead compounds could be obtained. For the first time nonphenolic and small low nanomolar potent, SAM competitive COMT inhibitors are reported. These compounds represent a novel series of potent COMT inhibitors that might be further optimized to new drugs useful for the treatment of Parkinson's disease, as adjuncts in levodopa based therapy, or for the treatment of schizophrenia.
Compositions for Treatment of Cystic Fibrosis and Other Chronic Diseases
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Paragraph 0553, (2015/09/22)
The present invention relates to pharmaceutical compositions comprising an inhibitor of epithelial sodium channel activity in combination with at least one ABC Transporter modulator compound of Formula A, Formula B, Formula C, or Formula D. The invention also relates to pharmaceutical formulations thereof, and to methods of using such compositions in the treatment of CFTR mediated diseases, particularly cystic fibrosis using the pharmaceutical combination compositions.
