89922-82-7Relevant academic research and scientific papers
Synthesis of Tetramic Acid Fragments Derived from Vancoresmycin Showing Inhibitory Effects towards S. aureus
Wingen, Lukas Martin,Rausch, Marvin,Schneider, Tanja,Menche, Dirk
, p. 1390 - 1393 (2020)
An efficient route to various vancoresmycin-type tetramic acids has been developed. The modular route is based on an effective Fries-type rearrangement to introduce various appending acetyl residues. The minimum inhibitory concentration (MIC) values of the new tetramic acids against Staphylococcus aureus and Escherichia coli were determined, revealing that three of the new compounds exhibit antimicrobial activity against S. aureus. These bioactive compounds were structurally most closely related to the authentic vancoresmycin building block. Additionally, the compounds induced a lial-lux bioreporter, which responds to cell wall stress induced by antibiotics that interfere with the lipid II biosynthesis cycle. These data suggest the tetramic acid moiety to be a part of the vancoresmycin pharmacophore.
Asymmetric Synthesis of ent-Fissistigmatin C
Xu, Dongyang,Hu, Jiadong,Chen, Le,Chen, Lu,Su, Jiang,Yang, Jinjin,Deng, Siyu,Zhang, Hongli,Xie, Weiqing
, p. 93 - 96 (2021)
The asymmetric synthesis of ent-fissistigmatin C is successively accomplished in 12 steps (longest linear sequence (LLS)). Relying on the enantioselective coupling of aliphatic aldehyde with 2-hydroxychalcone promoted by cooperative organocatalysts, the pivotal linkage of ent-fissistigmatin C between the flavonoid and the sesquiterpenoid fragment was stereoselectively established. An unprecedented final-stage radical cascade was also featured in this synthesis, which enabled the simultaneous establishment of the trans-decalin framework via forging two consecutive C-C bonds in one step.
Total Synthesis and Computational Investigations of Sesquiterpene-Tropolones Ameliorate Stereochemical Inconsistencies and Resolve an Ambiguous Biosynthetic Relationship
Bemis, Christopher Y.,Ungarean, Chad N.,Shved, Alexander S.,Jamieson, Cooper S.,Hwang, Taehwan,Lee, Ken S.,Houk,Sarlah, David
, p. 6006 - 6017 (2021)
The sesquiterpene-tropolones belong to a distinctive structural class of meroterpene natural products with impressive biological activities, including anticancer, antifungal, antimalarial, and antibacterial. In this article, we describe a concise, modular
Diene-transmissive cycloadditions: Control of monocycloaddition by self-assembly on a lewis acid template
Souweha, Michael Santos,Arab, Akram,ApSimon, Megan,Fallis, Alex G.
, p. 615 - 618 (2007)
The sequential control of diene-transmissive Diels-Alder reactions to expand their versatility for natural product synthesis and the preparation of diversity oriented libraries is described. Self-assembly of the components (trienol 5 and methyl acrylate) via a Lewis acid template proceeds with regio-, diastereo-, and enantioselective [(S)-BINOL added] control to the monoadduct. In contrast, no cycloaddition reaction occurred at 22°C in the absence of catalyst. This protocol obliterates the necessity of tether installation for an intramolecular cyclization.
Approach to the homoerythrina alkaloids using a tandem N-alkylation/ azomethine ylide cycloaddition
Pearson, William H.,Kropf, Jeffrey E.,Choy, Allison L.,Ill, Young Lee,Kampf, Jeff W.
, p. 4135 - 4148 (2007)
(Chemical Equation Presented) Synthetic efforts toward the homoerythrina alkaloids 1-3 are described. Two separate model systems guided the pivotal [3 + 2] azomethine ylide cycloaddition cascade to form the A-C rings of these alkaloids. The cycloaddition
Mechanistic Details of Asymmetric Bromocyclization with BINAP Monoxide: Identification of Chiral Proton-Bridged Bisphosphine Oxide Complex and Its Application to Parallel Kinetic Resolution
Hamashima, Yoshitaka,Hirokawa, Ryo,Hisanaga, Tatsunari,Ichikawa, Mamoru,Kawato, Yuji,Nagao, Yoshihiro,Takita, Ryo,Watanabe, Kohei,Yamashita, Kenji
supporting information, p. 3913 - 3924 (2022/03/15)
The mechanism of our previously reported catalytic asymmetric bromocyclization reactions using 2,2′-bis(diphenylphosphino)-1,1′-binaphthyl (BINAP) monoxide was examined in detail by the means of control experiments, NMR studies, X-ray structure analysis, and CryoSpray electrospray ionization mass spectrometry (ESI-MS) analysis. The chiral BINAP monoxide was transformed to a key catalyst precursor, proton-bridged bisphosphine oxide complex (POHOP·Br), in the presence of N-bromosuccinimide (NBS) and contaminating water. The thus-formed POHOP further reacts with NBS to afford BINAP dioxide and molecular bromine (Br2) simultaneously in equimolar amounts. While the resulting Br2 is activated by NBS to form a more reactive brominating reagent (Br2─NBS), BINAP dioxide serves as a bifunctional catalyst, acting as both a Lewis base that reacts with Br2─NBS to form a chiral brominating agent (P═O+─Br) and also as a Br?nsted base for the activation of the substrate. By taking advantage of this novel concerted Lewis/Br?nsted base catalysis by BINAP dioxide, we achieved the first regio- and chemodivergent parallel kinetic resolutions (PKRs) of racemic unsymmetrical bisallylic amides via bromocyclization.
Modular Fragment Synthesis and Bioinformatic Analysis Propose a Revised Vancoresmycin Stereoconfiguration
Adamek, Martina,Essig, Sebastian,Kurz, Michael,Menche, Dirk,Sch?nenbroicher, Max,Seul, Maximilian,Spindler, Stefanie,Wingen, Lukas M.,Ziemert, Nadine
supporting information, p. 1175 - 1180 (2021/01/13)
Elaborate fragments of the proposed stereostructure of the complex polyketide antibiotic vancoresmycin have been synthesized in a stereoselective fashion based on a modular and convergent approach. Significant nuclear magnetic resonance differences in one of these subunits compared with the natural product question the proposed stereoconfiguration. Consequently, an extensive bioinformatics analysis of the biosynthetic gene cluster was carried out, leading to a revised stereoconfigurational proposal for this highly potent antibiotic.
MACROCYCLIC DIAMINE DERIVATIVES AS ENT INHIBITORS FOR THE TREATMENT OF CANCERS, AND COMBINATION THEREOF WITH ADENOSINE RECEPTOR ANTAGONISTS
-
Paragraph 0486; 0545, (2021/10/15)
The present invention relates to macrocyclic diamine derivatives of formula II, including pharmaceutically acceptable salts and solvates thereof. Compounds of the invention are inhibitors of ENT family transporter, especially of ENT1, and are useful as therapeutic compounds for the treatment of cancers. The invention also relates to the combined use of the macrocyclic diamine derivatives with an adenosine receptor antagonist, for the treatment of cancers.
Synthesis of Highly Functionalized Hydrindanes via Sequential Organocatalytic Michael/Mukaiyama Aldol Addition and Telescoped Hydrozirconation/Cross-Coupling as Key Steps: En Route to the AB System of Clifednamides
Sinast, Moritz,Claasen, Birgit,St?ckl, Yannick,Greulich, Andreas,Zens, Anna,Baro, Angelika,Laschat, Sabine
, p. 7537 - 7551 (2021/06/25)
The AB ring systems of the clifednamide family, polycyclic tetramate macrolactames (PoTeMs), were prepared by a new, convergent approach employing an intramolecular Diels-Alder (IMDA) reaction. Key steps comprise an organocatalytic Michael addition (>90% enantiomeric excess (ee)), a Mukaiyama aldol reaction for the convergent installation of a diene moiety, and a telescoped hydrozirconation/cross-coupling grafting an enone. The following IMDA furnished a highly functionalized hydrindane (diastereomeric ratio (dr) = 91:1) with the same configuration as the clifednamide scaffold. Advantages of this route are only one required protecting group, 13% overall yield over 9 steps (reduced from previously 17 steps/1.3% overall), and the potential access to the key intermediates in the clifednamide biosynthesis.
Highly Regioselective 5-endo-tet Cyclization of 3,4-Epoxy Amines into 3-Hydroxypyrrolidines Catalyzed by La(OTf)3
Hoshino, Yoshihiko,Iwabuchi, Yoshiharu,Kuriyama, Yuse,Sasano, Yusuke,Uesugi, Shun-ichiro,Yamaichi, Aoto
, p. 1961 - 1965 (2021/01/04)
Highly regioselective intramolecular aminolysis of 3,4-epoxy amines has been achieved. Key features of this reaction are (1) chemoselective activation of epoxides in the presence of unprotected aliphatic amines in the same molecules by a La(OTf)3 catalyst and (2) excellent regioselectivity for anti-Baldwin 5-endo-tet cyclization. This reaction affords 3-hydroxy-2-alkylpyrrolidines stereospecifically in high yields. DFT calculations revealed that the regioselectivity might be attributed to distortion energies of epoxy amine substrates. The use of this reaction was demonstrated by the first enantioselective synthesis of an antispasmodic agent prifinium bromide.
