13669-10-8Relevant academic research and scientific papers
Tert-BuOK-Catalyzed condensation of ethyl diazoacetate to aldehydes and palladium-catalyzed 1,2-hydrogen migration for the synthesis of β-ketoesters under solvent-free conditions
Chen, Shufeng,Yuan, Fang,Zhao, Haiying,Li, Baoguo
, p. 12616 - 12620 (2013)
A mild and convenient method for the condensation of ethyl diazoacetate (EDA) with aldehydes catalyzed by tert-BuOK under solvent-free conditions was developed. The corresponding α-diazo-β-hydroxy esters were further converted into β-ketoesters through palladium-catalyzed 1,2-hydrogen migration under neat conditions. The two-step transformation exemplifies a simple method for the efficient and green synthesis of β-ketoesters. The Royal Society of Chemistry 2013.
Trifluoroethanol as a Unique Additive for the Chemoselective Electrooxidation of Enamines to Access Unsymmetrically Substituted NH-Pyrroles
Baidya, Mrinmay,De Sarkar, Suman,Maiti, Debabrata,Roy, Lisa
supporting information, (2021/12/23)
An electrochemical method for the synthesis of unsymmetrically substituted NH-pyrroles is described. The synthetic strategy comprises a challenging heterocoupling between two structurally diverse enamines via sequential chemoselective oxidation, addition,
Regioselective Synthesis of N2-Aryl 1,2,3-Triazoles via Electro-oxidative Coupling of Enamines and Aryldiazonium Salts
Baidya, Mrinmay,Mallick, Samrat,De Sarkar, Suman
supporting information, p. 1274 - 1279 (2022/02/14)
An efficient synthetic route for the construction of N2-aryl 1,2,3-triazoles is reported via sequential C-N bond formation and electro-oxidative N-N coupling under metal-free conditions. Readily accessible 2-aminoacrylates and aryldiazonium salts were used as starting materials, and the developed protocol displays excellent functional group tolerance, allowing an extensive range of substrate scope up to 91% isolated yield. Various mechanistic studies, along with the isolation of an intermediate adduct, refer to successive ionic and radical reaction sequences.
Electrochemical Oxidative Cyclization: Synthesis of Polysubstituted Pyrrole from Enamines
Chen, Zhiwei,Shi, Guang,Tang, Wei,Sun, Jie,Wang, Wenxing
supporting information, p. 951 - 955 (2021/02/03)
A conceptually novel method for the preparation of pyrrole is described by electrochemical-oxidation-induced intermolecular annulation via enamines. In a simple undivided cell, based on a sodium acetate-facilitated, polysubstituted pyrrole derivations has been facilely synthesized under external oxidant-free condition. This electrosynthetic approach providing an environmentally benign protocol for C?C bond cross-coupling and oxidative annulation, which features unparalleled broad scope of substrates and practicality.
Sulfur-controlled and rhodium-catalyzed formal (3 + 3) transannulation of thioacyl carbenes with alk-2-enals and mechanistic insights
Wu, Qiuyue,Dong, Ziyang,Xu, Jiaxi,Yang, Zhanhui
supporting information, p. 3173 - 3180 (2021/04/21)
A rhodium-catalyzed denitrogenative formal (3 + 3) transannulation of 1,2,3-thiadiazoles with alk-2-enals is achieved, producing 2,3-dihydrothiopyran-4-ones in moderate to excellent yields. An inverse KIE of 0.49 is obtained, suggesting the reversibility of the oxidative addition of thioacyl Rh(i) carbenes to alk-2-enals. The late-stage structural modifications of steroid compounds are realized. Moreover, our studies show that thioacyl carbenes have different reactivities to those of α-oxo and α-imino carbenes, and highlight the importance of heteroatoms in deciding the reactivities of heterovinyl carbenes.
Cu-Mediated Expeditious Annulation of Alkyl 3-Aminoacrylates with Aryldiazonium Salts: Access to Alkyl N2-Aryl 1,2,3-Triazole-carboxylates for Druglike Molecular Synthesis
Liu, Hao-Nan,Cao, Hao-Qiang,Cheung, Chi Wai,Ma, Jun-An
supporting information, p. 1396 - 1401 (2020/02/22)
Alkyl N-aryl 1,2,3-triazole-carboxylates are important molecules or intermediates in medicinal chemistry, but the synthesis of N2-aryl counterparts remains elusive. Herein, we describe a Cu-mediated annulation reaction of alkyl 3-aminoacrylates with aryldiazonium salts, both of which are readily available substrates. Furthermore, alkyl 2-aminoacrylates are also viable substrates. Diverse alkyl N2-aryl 1,2,3-triazole-carboxylates and their analogues can be rapidly prepared under mild conditions. Especially, this protocol allows one to access several druglike variants of carbonic anhydrase inhibitors and celecoxib.
Radical Aza-Cyclization of α-Imino-oxy Acids for Synthesis of Alkene-Containing N-Heterocycles via Dual Cobaloxime and Photoredox Catalysis
Tu, Jia-Lin,Liu, Jia-Li,Tang, Wan,Su, Ma,Liu, Feng
supporting information, p. 1222 - 1226 (2020/02/15)
Nitrogen-containing heterocycles are prevalent in both naturally and synthetically bioactive molecules. We report herein an unprecedented protocol for radical aza-cyclization of α-imino-oxy acids with pendant alkenes via synergistic photoredox and cobaloxime catalysis. With or without alkenes as the intermolecular cross-coupling partners, the transformation provides a variety of corresponding alkene-containing dihydropyrrole products in satisfactory yields. In the presence of external alkenes, the tandem reaction generates E-selective coupling products with excellent chemo- and stereoselectivity.
Design, Synthesis, and Biochemical Characterization of Non-Native Antagonists of the Pseudomonas aeruginosa Quorum Sensing Receptor LasR with Nanomolar IC50 Values
Blackwell, Helen E.,Manson, Daniel E.,Nyffeler, Kayleigh E.,O'Reilly, Matthew C.
, (2020/03/04)
Quorum sensing (QS), a bacterial cell-to-cell communication system mediated by small molecules and peptides, has received significant interest as a potential target to block infection. The common pathogen Pseudomonas aeruginosa uses QS to regulate many of its virulence phenotypes at high cell densities, and the LasR QS receptor plays a critical role in this process. Small molecule tools that inhibit LasR activity would serve to illuminate its role in P. aeruginosa virulence, but we currently lack highly potent and selective LasR antagonists, despite considerable research in this area. V-06-018, an abiotic small molecule discovered in a high-throughput screen, represents one of the most potent known LasR antagonists but has seen little study since its initial report. Herein, we report a systematic study of the structure-activity relationships (SARs) that govern LasR antagonism by V-06-018. We synthesized a focused library of V-06-018 derivatives and evaluated the library for bioactivity using a variety of cell-based LasR reporter systems. The SAR trends revealed by these experiments allowed us to design probes with 10-fold greater potency than that of V-06-018 and 100-fold greater potency than other commonly used N-acyl-l-homoserine lactone (AHL)-based LasR antagonists, along with high selectivities for LasR. Biochemical experiments to probe the mechanism of antagonism by V-06-018 and its analogues support these compounds interacting with the native ligand-binding site in LasR and, at least in part, stabilizing an inactive form of the protein. The compounds described herein are the most potent and efficacious antagonists of LasR known and represent robust probes both for characterizing the mechanisms of LuxR-type QS and for chemical biology research in general in the growing QS field.
Gram-Negative Antibiotic Active through Inhibition of an Essential Riboswitch
Geddes, Emily J.,Hergenrother, Paul J.,Lau, Gee W.,Lee, Hyang Yeon,Motika, Stephen E.,Ulrich, Rebecca J.
supporting information, p. 10856 - 10862 (2020/07/04)
Multidrug-resistant Gram-negative (GN) infections for which there are few available treatment options are increasingly common. The development of new antibiotics for these pathogens is challenging because of the inability of most small molecules to accumulate inside GN bacteria. Using recently developed predictive guidelines for compound accumulation in Escherichia coli, we have converted the antibiotic Ribocil C, which targets the flavin mononucleotide (FMN) riboswitch, from a compound lacking whole-cell activity against wild-type GN pathogens into a compound that accumulates to a high level in E. coli, is effective against Gram-negative clinical isolates, and has efficacy in mouse models of GN infections. This compound allows for the first assessment of the translational potential of FMN riboswitch binders against wild-type Gram-negative bacteria.
ANTIBIOTICS EFFECTIVE FOR GRAM-NEGATIVE PATHOGENS
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Page/Page column 90; 91; 92, (2019/10/04)
Disclosed herein are antibacterial compounds that accumulate in Gram-negative bacteria, methods of preparing the compounds, and methods of using the compounds to inhibit or kill microbes, and methods of treating microbial infections, such as Gram-negative
