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71.
72.
Olalla Barreiro-Costa Gabriela Morales-Noboa Patricio Rojas-Silva Eliana Lara-Barba Javier Santamaría-Aguirre Natalia Bailn-Moscoso Juan Carlos Romero-Benavides Ana Herrera Cristina Cueva Lenin Ron-Garrido Ana Poveda Jorge Heredia-Moya 《Molecules (Basel, Switzerland)》2021,26(16)
This work focuses on the search and development of drugs that may become new alternatives to the commercial drugs currently available for treatment of leishmaniasis. We have designed and synthesized 12 derivatives of bis(spiropyrazolone)cyclopropanes. We then characterized their potential application in therapeutic use. For this, the in vitro biological activities against three eukaryotic models—S. cerevisiae, five cancer cell lines, and the parasite L. mexicana—were evaluated. In addition, cytotoxicity against non-cancerous mammalian cells has been evaluated and other properties of interest have been characterized, such as genotoxicity, antioxidant properties and, in silico predictive adsorption, distribution, metabolism, and excretion (ADME). The results that we present here represent a first screening, indicating two derivatives of bis(spiropyrazolone)cyclopropanes as good candidates for the treatment of leishmaniasis. They have good specificity against parasites with respect to mammalian cells. 相似文献
73.
Franziska Bendrath Abiodun Falodun Zharylkasyn A. Abilov Alexander Villinger Peter Langer 《Journal of heterocyclic chemistry》2014,51(3):835-840
Pyrazoles and isoxazoles with cyclopropanated side‐chain were prepared by cyclization of cyclopropanated 1,3,5‐tricarbonyl compounds with hydrazine and hydroxylamine, respectively. The regioselectivity is influenced by the reaction conditions. 相似文献
74.
Brackmann F Schill H de Meijere A 《Chemistry (Weinheim an der Bergstrasse, Germany)》2005,11(22):6593-6600
Protected racemic and enantiomerically pure 3,4-(aminomethano)prolines rac-9 and (2S,2'R,3R,4R)-9 have been prepared applying a titanium-mediated reductive cyclopropanation as a key step. Thus, cyclopropanations of N,N-dibenzylformamide with titanacyclopropanes generated in situ from racemic or enantiomerically pure tert-butyl N-Boc-3,4-dehydroprolinates rac-8 or (S)-8 proceed diastereoselectively, and furnish the protected racemic and enantiomerically pure diamino acid 9. The latter was incorporated into three tripeptides containing glycyl, alanyl and phenylalanyl moieties. 相似文献
75.
Lingran Kong Jingjing Liu Prof. Dr. Tuoping Luo 《Angewandte Chemie (International ed. in English)》2018,57(3):760-764
A new strategy was devised for the total synthesis of highly oxidized ent‐kauranoids. A highly regio‐ and diastereoselective intermolecular Diels–Alder cycloaddition involving a diene embedded in a substituted bicyclo[4.1.0] skeleton was used to assemble all carbon centers but C17 of the target molecule at an early stage of the synthesis. Subsequent synthetic steps, including redox manipulations, SmI2‐mediated cyclization, and isomerization reactions, afforded the antitumor natural product maoecrystal P. 相似文献
76.
Lewis Acid Catalyzed Enantioselective Desymmetrization of Donor–Acceptor meso‐Diaminocyclopropanes 下载免费PDF全文
Daniele Perrotta Ming‐Ming Wang Prof. Dr. Jérôme Waser 《Angewandte Chemie (International ed. in English)》2018,57(18):5120-5123
The first Lewis acid catalyzed enantioselective ring‐opening desymmetrization of a donor–acceptor meso‐diaminocyclopropane is reported. The copper(II)‐catalyzed Friedel–Crafts alkylation of indoles and one pyrrole with an unprecedented meso‐diaminocyclopropane delivered enantioenriched, diastereomerically pure urea products, which are structurally related to natural and synthetic bioactive compounds. The development of a new ligand through the investigation of an underexplored subclass of bis(oxazoline) ligands was essential for achieving high enantioselectivities. 相似文献
77.
Asymmetric [3+2] Photocycloadditions of Cyclopropanes with Alkenes or Alkynes through Visible‐Light Excitation of Catalyst‐Bound Substrates 下载免费PDF全文
Xiaoqiang Huang Jiahui Lin Tianqi Shen Dr. Klaus Harms Dr. Marianna Marchini Prof. Dr. Paola Ceroni Prof. Dr. Eric Meggers 《Angewandte Chemie (International ed. in English)》2018,57(19):5454-5458
The herein reported visible‐light‐activated catalytic asymmetric [3+2] photocycloadditions between cyclopropanes and alkenes or alkynes provide access to chiral cyclopentanes and cyclopentenes, respectively, in 63–99 % yields and with excellent enantioselectivities of up to >99 % ee. The reactions are catalyzed by a single bis‐cyclometalated chiral‐at‐metal rhodium complex (2–8 mol %) which after coordination to the cyclopropane generates the visible‐light‐absorbing complex, lowers the reduction potential of the cyclopropane, and provides the asymmetric induction and overall stereocontrol. Enabled by a mild single‐electron‐transfer reduction of directly photoexcited catalyst/substrate complexes, the presented transformations expand the scope of catalytic asymmetric photocycloadditions to simple mono‐acceptor‐substituted cyclopropanes affording previously inaccessible chiral cyclopentane and cyclopentene derivatives. 相似文献
78.
《Angewandte Chemie (International ed. in English)》2017,56(35):10587-10591
Reactions of 2‐arylcyclopropane dicarboxylates with naphthoquinones are reported. The key feature was the use of catalytic amounts of SnCl2, which acts as both an electron donor and a Lewis acid. By an in situ umpolung of naphthoquinone the formerly electrophilic species is converted into a nucleophile that is able to trigger the ring‐opening of the three‐membered ring with formation of a new C−C bond. Treatment of these products with base under oxidative conditions resulted—through loss of methyl formate—in cyclopentannulated products with fully conjugated π systems exhibiting intensive absorptions in the visible range. 相似文献
79.
《Angewandte Chemie (International ed. in English)》2017,56(45):14293-14296
Lewis‐acid‐catalyzed reactions of 2‐substituted cyclopropane 1,1‐dicarboxylates with thioketones are described. Highly substituted tetrahydrothiophenes with two adjacent quaternary carbon atoms were obtained in a stereospecific manner under mild conditions and in high yield when using AlCl3 as Lewis acid. Moreover, an intramolecular approach was successfully implemented to gain access to sulfur‐bridged [n .2.1] bicyclic ring systems. Conversion of selenoketones, the heavier analogues, under similar conditions resulted in the formation of various tetrahydroselenophenes. 相似文献
80.
Dr. Longyang Dian Dr. Daniel S. Müller Prof. Dr. Ilan Marek 《Angewandte Chemie (International ed. in English)》2017,56(24):6783-6787
The highly diastereo- and enantioselective formation of polysubstituted cyclopropanes was easily achieved through the asymmetric copper-catalyzed carbomagnesiation reaction of nonfunctionalized cyclopropene derivatives. The carbometalated species generated in situ readily undergo C−C and C−X bond-forming reactions with various electrophiles with complete retention of configuration. 相似文献