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Il-Chun Kwon Young Kook Koh Jun-Hyeak Choi Hong-Seok Kim 《Journal of heterocyclic chemistry》1996,33(6):1883-1886
Thiazole-containing polyether podands were prepared from the reactions of hydroxymethylthiazole derivatives with di-p-tosylates of corresponding tri, terra, pentaethylene glycols in the presence of potassium hydride. 相似文献
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A series of benzo-crown ethers containing the thiazole subcyclic moity have been synthesized. Reaction of 1,2-bis(thioamidomethyloxy)benzene 2 with ethyl bromopyruvate in ethanol provided 1,2-bis(thiazolyl)benzene 4 (80%) along with thiazole 5 (14%). Reduction of 4 with lithium aluminum hydride followed by mesylationbromination gave 7 . Similar treatment of 5 with lithium aluminum hydride followed by bromination resulted in 12 . Benzo-crown ethers 8, 9, 10 , and 13 were prepared from the reactions of 4-bromomethylthiazole derivatives 7 and 12 with catechol and resorcinol derivatives in the presence of potassium hydride. 相似文献
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[reaction: see text] A short synthesis of epothilone B and D is reported. The key step for generating the C12-13-trisubstituted Z-double bond uses a ring-closing metathesis reaction of a disiloxane to form a nine-membered silicon-tethered ring. 相似文献
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MCM‐41‐Biurea‐Pd is introduced as a new, heterogeneous and reusable catalyst for C–C and C–heteroatom bond formation between various aryl halides, phenols and amines, in the presence of Ph3SnCl (Stille reaction) in PEG‐400 as a green solvent at room temperature. The structure of the functionalized MCM‐41 was analysed using various techniques. 相似文献
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Convenient Synthesis of Novel Quinazoline Congeners via Copper Catalyzed C–N/C–S Coupling and Their Biological Evaluation 下载免费PDF全文
Harshad P. Lakum Dhruvin R. Shah Kishor H. Chikhalia 《Journal of heterocyclic chemistry》2016,53(1):209-219
A library of novel quinazoline scaffolds endowed with semicarbazide/oxadiazole thiol motif synthesized via an efficient and sustainable copper catalyzed C–N/C–S coupling is reported, making the presented methodology extremely valuable from economic and environmental point of view. Among the all synthesized compounds screened for in vitro antibacterial, antifungal, and anti‐TB activity, 7b , 7c , 7f , 9b , 9c , 9i , and 9j showed excellent inhibitory effect on particular strain of bacteria, fungi, and M. tuberculosis H37Rv as well. All the newly synthesized derivatives were well characterized by their IR, 1H NMR, 13C NMR, mass spectroscopy as well as elemental analysis. 相似文献
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《Helvetica chimica acta》2017,100(11)
Monothiomalonates (MTM s) are surrogates of thioester enolates that allow for stereoselective C–C bond formations under mild conditions and thereby afford access to synthetically versatile thioester derivatives. Here we present a straightforward synthetic route to MTM s that proceeds through nucleophilic ring‐opening of Meldrum 's acid derivatives followed by O‐alkylation of the resulting malonic acid half thioesters with alkyl triflates or acetimidates as electrophiles. The method affords MTM s in overall yields of 34 – 92% and allows for variations of the oxo‐ and thioester moieties as well as the substituent at the C(α ) position. 相似文献
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Iori Morita Takahiro Mori Takaaki Mitsuhashi Shotaro Hoshino Yoshimasa Taniguchi Takashi Kikuchi Kei Nagae Norihiro Nasu Makoto Fujita Tomohiko Ohwada Ikuro Abe 《Angewandte Chemie (International ed. in English)》2020,59(10):3988-3993
C–S bond formation reactions are widely distributed in the biosynthesis of biologically active molecules, and thus have received much attention over the past decades. Herein, we report intramolecular C–S bond formation by a P450 monooxygenase, TleB, which normally catalyzes a C?N bond formation in teleocidin biosynthesis. Based on the proposed reaction mechanism of TleB, a thiol‐substituted substrate analogue was synthesized and tested in the enzyme reaction, which afforded the unprecedented sulfur‐containing thio‐indolactam V, in addition to an unusual indole‐fused 6/5/8‐tricyclic product whose structure was determined by the crystalline sponge method. Interestingly, conformational analysis revealed that the SOFA conformation is stable in thio‐indolactam V, in sharp contrast to the major TWIST form in indolactam V, resulting in differences in their biological activities. 相似文献
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Dr. Shubhankar Kumar Bose Andrea Deißenberger Antonius Eichhorn Prof. Dr. Patrick G. Steel Prof. Dr. Zhenyang Lin Prof. Dr. Todd B. Marder 《Angewandte Chemie (International ed. in English)》2015,54(40):11843-11847
A zinc‐catalyzed combined C? X and C? H borylation of aryl halides using B2pin2 (pin=OCMe2CMe2O) to produce the corresponding 1,2‐diborylarenes under mild conditions was developed. Catalytic C? H bond activation occurs ortho to the halide groups if such a site is available or meta to the halide if the ortho position is already substituted. This method thus represents a novel use of a group XII catalyst for C? H borylation. This transformation does not proceed via a free aryne intermediate, but a radical process seems to be involved. 相似文献
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Sergio García-Muoz Míriam lvarez-Corral Leticia Jimnez-Gonzlez Cristbal Lpez-Snchez Antonio Rosales Manuel Muoz-Dorado Ignacio Rodríguez-García 《Tetrahedron》2006,62(52):12182-12190
The natural dihydrobenzofuran neolignan 1 and its derivative 3 have been prepared through intramolecular C–H insertion catalyzed by a Rh(II) chiral complex. Moderate diastereo and enantioselectivities were observed. The cis and trans diastereomers were separated and unambiguously identified. The absolute configurations of the major isomers were established through chiral HPLC analysis and study of the Cotton effects in their circular dichroism curves. 相似文献
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A rapid access to 2,2′‐bithiazole‐based copolymers has been developed on the basis of the sequential palladium‐catalyzed C H/C X and C H/C H coupling reactions. To assemble a “copolymer” through homopolymerization, a type of symmetric A‐B‐A‐type building block is designed as the monomer and prepared via the regioselective C5 H arylation of thiazole. A PdCl2/CuCl‐cocatalyzed oxidative C H/C H homopolymerization has been established to afford the 2,2′‐bithiazole‐based copolymers with high Mn (up to 69400). The current protocol features atom‐ and step‐economy and exhibits a potential in the highly efficient construction of conjugated copolymers.
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《中国化学会会志》2017,64(12):1408-1416
An improved and greener protocol has been developed for the synthesis of 2,4‐disubstituted thiazoles via C–Br, C–S, and, C–N bond formations in a single step from readily available ketones, N‐bromosuccinimide (NBS), and thiourea catalyzed by citric acid in a mixture of ethanol and water (3:1) under reflux conditions. This method has the advantages of freedom from the isolation of lachrymatory α‐bromoketones, ease of carrying out, cleaner reaction profile, broad substrate scope, freedom from chromatographic purification, and suitability for large‐scale synthesis. 相似文献
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Yuanming Li Dr. Shyamal Chakrabarty Dr. Christian Mück‐Lichtenfeld Prof. Dr. Armido Studer 《Angewandte Chemie (International ed. in English)》2016,55(2):802-806
A novel and efficient approach to ortho‐trialkylstannyl arylphosphanes by the reaction of arynes generated in situ with stannylated phosphanes (R3Sn? PR2) is described. Concurrent C? P and C? Sn bond formation occurs with high yields, and stannylated products are easily transformed into valuable ortho‐substituted arylphosphanes. The reaction features high efficiency, good regioselectivity, and excellent practicality. 相似文献
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《应用有机金属化学》2017,31(10)
Eight heteroleptic palladium complexes containing both N‐heterocyclic carbenes and NH‐heterocycle azoles (pyrazole and indazole) were synthesized and characterized, and their structures were unambiguously confirmed using single‐crystal X‐ray diffraction. Further investigation of the complexes as catalysts in the Suzuki–Miyaura reaction and Buchwald–Hartwig amination revealed good reactivities for aryl chlorides. 相似文献
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Gareth W. V. Cave Andrew J. Hallett William Errington Jonathan P. Rourke 《Angewandte Chemie (International ed. in English)》1998,37(23):3270-3272
13 C NMR spectroscopy as well as the short bond between the platinum and the C4 atom of the pyridine ring in 1 (1.95 Å) indicate the formation of a novel carbene species. Compound 1 is remarkably stable (m.p. 246°C), probably due to the presence of intramolecular hydrogen bonds, and is formed instead of the expected cyclometalated product. R=n-hexyl. 相似文献