17071-29-3Relevant articles and documents
Non-metal Lewis acid-catalyzed cross-Claisen condensation for β-keto esters
Han, Zhengyu,Huang, Hai,Meng, Fuliang,Yang, Zhenkun,Zhang, Tianyu,Zhou, Dapeng
supporting information, p. 9163 - 9166 (2021/11/16)
In this work, we disclose a new catalytic and highly chemoselective cross-Claisen condensation of esters. In the presence of TBSNTf2 as a non-metal Lewis acid, various esters can undergo cross-Claisen condensation to form β-keto esters which are important building blocks. Compared with the traditional Claisen condensation, this process, employing silyl ketene acetals (SKAs) as carbonic nucleophiles to achieve cross-Claisen condensation, requires mild conditions and has good tolerance of functional groups. This journal is
Amide/Ester Cross-Coupling via C-N/C-H Bond Cleavage: Synthesis of β-Ketoesters
Chen, Jiajia,Joseph, Devaneyan,Xia, Yuanzhi,Lee, Sunwoo
, p. 5943 - 5953 (2021/04/02)
Activated primary, secondary, and tertiary amides were coupled with enolizable esters in the presence of LiHMDS to obtain good yields of β-ketoesters at room temperature. Notably, this protocol provides an efficient, mild, and high chemoselectivity method
Deconstructing Noncovalent Kelch-like ECH-Associated Protein 1 (Keap1) Inhibitors into Fragments to Reconstruct New Potent Compounds
Pallesen, Jakob S.,Narayanan, Dilip,Tran, Kim T.,Solbak, Sara M. ?.,Marseglia, Giuseppe,S?rensen, Louis M. E.,H?j, Lars J.,Munafò, Federico,Carmona, Rosa M. C.,Garcia, Anthony D.,Desu, Haritha L.,Brambilla, Roberta,Johansen, Tommy N.,Popowicz, Grzegorz M.,Sattler, Michael,Gajhede, Michael,Bach, Anders
supporting information, p. 4623 - 4661 (2021/05/07)
Targeting the protein-protein interaction (PPI) between nuclear factor erythroid 2-related factor 2 (Nrf2) and Kelch-like ECH-associated protein 1 (Keap1) is a potential therapeutic strategy to control diseases involving oxidative stress. Here, six classes of known small-molecule Keap1-Nrf2 PPI inhibitors were dissected into 77 fragments in a fragment-based deconstruction reconstruction (FBDR) study and tested in four orthogonal assays. This gave 17 fragment hits of which six were shown by X-ray crystallography to bind in the Keap1 Kelch binding pocket. Two hits were merged into compound 8 with a 220-380-fold stronger affinity (Ki = 16 μM) relative to the parent fragments. Systematic optimization resulted in several novel analogues with Ki values of 0.04-0.5 μM, binding modes determined by X-ray crystallography, and enhanced microsomal stability. This demonstrates how FBDR can be used to find new fragment hits, elucidate important ligand-protein interactions, and identify new potent inhibitors of the Keap1-Nrf2 PPI.
Modular Tuning of Electrophilic Reactivity of Iridium Nitrenoids for the Intermolecular Selective α-Amidation of β-Keto Esters
Lee, Minhan,Jung, Hoimin,Kim, Dongwook,Park, Jung-Woo,Chang, Sukbok
, p. 11999 - 12004 (2020/08/06)
We report herein an Ir-catalyzed intermolecular amino group transfer to β-keto esters (amides) to access α-aminocarbonyl products with excellent chemoselectivity. The key strategy was to engineer electrophilicity of the putative Ir-nitrenoids by tuning electronic property of the κ2-N,O chelating ligands, thus facilitating nucleophilic addition of enol π-bonds of 1,3-dicarbonyl substrates.
One-Pot, Tandem Wittig Hydrogenation: Formal C(sp3)-C(sp3) Bond Formation with Extensive Scope
Devlin, Rory,Jones, David J.,Mcglacken, Gerard P.
supporting information, p. 5223 - 5228 (2020/07/14)
A one-pot, tandem Wittig hydrogenation of aldehydes with stabilized ylides is reported, representing a formal C(sp3)-C(sp3) bond construction. The tandem reaction operates under mild conditions, is high yielding, and is broad in scope. Chemoselectivity for olefin reduction is observed, and the methodology is demonstrated in the synthesis of lapatinib analogues and a formal synthesis of (±)-cuspareine. Early insights suggest that the chemoselectivity observed in the reduction step is due to partial poisoning of the catalyst, after step one, thus adding to the power of the one-pot procedure.
Synthesis and Pharmacological Evaluation of Triazolopyrimidinone Derivatives as Noncompetitive, Intracellular Antagonists for CC Chemokine Receptors 2 and 5
Ortiz Zacarías, Natalia V.,Van Veldhoven, Jacobus P. D.,Den Hollander, Lisa S.,Dogan, Burak,Openy, Joseph,Hsiao, Ya-Yun,Lenselink, Eelke B.,Heitman, Laura H.,Ijzerman, Adriaan P.
, p. 11035 - 11053 (2019/12/24)
CC chemokine receptors 2 (CCR2) and 5 (CCR5) are involved in many inflammatory diseases; however, most CCR2 and CCR5 clinical candidates have been unsuccessful. (Pre)clinical evidence suggests that dual CCR2/CCR5 inhibition might be more effective in the treatment of such multifactorial diseases. In this regard, the highly conserved intracellular binding site in chemokine receptors provides a new avenue for the design of multitarget ligands. In this study, we synthesized and evaluated the biological activity of a series of triazolopyrimidinone derivatives in CCR2 and CCR5. Radioligand binding assays first showed that they bind to the intracellular site of CCR2, and in combination with functional assays on CCR5, we explored structure-affinity/activity relationships in both receptors. Although most compounds were CCR2-selective, 39 and 43 inhibited β-arrestin recruitment in CCR5 with high potency. Moreover, these compounds displayed an insurmountable mechanism of inhibition in both receptors, which holds promise for improved efficacy in inflammatory diseases.
Asymmetric synthesis of (6R)-4-hydroxy-6-substituted-δ-lactones
Gaikwad, Ravindra D.,Rane, Monica D.,Bhat, Sujata V.
, p. 181 - 185 (2017/01/11)
A novel approach for the asymmetric synthesis of (6R)-4-hydroxy-6-substituted-δ-lactones has been achieved using asymmetric reduction of a prochiral ketone in the presence of (S)-(?)-diphenyl-prolinol/borane as a key step. The enantiomeric purity of the products was determined by chiral GC.
Synthesis of the 1,3,4-Oxadiazole Core through Thermolysis of Geminal Diazides
Erhardt, Hellmuth,Mohr, Fabian,Kirsch, Stefan F.
supporting information, p. 5629 - 5632 (2016/12/14)
The thermolysis of geminal diazides derived from acylacetate compounds is an efficient tool for the rapid construction of the 1,3,4-oxadiazole core. While a broad range of ethyl esters undergoes smooth transformation to the desired heterocycles that contain the ester moiety in moderate to high yields, the analogous tert-butyl esters give rise to the oxadiazoles with acyl groups, presumably through a pathway of decarboxylation followed by a new acyl transfer.
Variations on the Blaise Reaction: Synthesis of 3,5-Dioxopentanoates and 3-Amino-5-oxopent-3-enoates
Rao, H. Surya Prakash,Muthanna, Nandurka
supporting information, p. 2014 - 2018 (2016/08/09)
We have achieved a facile and convenient synthesis of a variety of 3,5-dioxopentanoates (3,5-diketo esters) and 3-amino-5-oxopent-3-enoates by a zinc-mediated condensation of readily available 3-oxopropanenitriles (α-cyano ketones) with ethyl bromoacetate. The reaction is a variation on the classical Blaise reaction, tuned to the synthesis of trifunctional compounds having 3,5-diketo ester or 3-enamino 5-keto ester functional groups. Our studies revealed that the Blaise reaction on the nitrile occurs in preference to the Reformatsky reaction on the neighboring ketone when the two functional groups are in a geminal relationship, as found in α-cyano ketones, possibly due to zinc complexation leading to increased electrophilicity of the nitrile.
Enantioselective Reduction of Ethyl 3-Oxo-5-phenylpentanoate with Whole-Cell Biocatalysts
Zadlo, Anna,Schrittwieser, Joerg H.,Koszelewski, Dominik,Kroutil, Wolfgang,Ostaszewski, Ryszard
supporting information, p. 1007 - 1011 (2016/03/01)
The biocatalytic stereoselective synthesis of a sterically demanding sec-alcohol (ethyl 3-hydroxy-5-phenylpentanoate) was investigated by starting from the corresponding prochiral ketone. Screening of a collection of microorganisms led to the identificati
