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1.
Miller TJ Farquar HD Sheybani A Tallini CE Saurage AS Fronczek FR Hammer RP 《Organic letters》2002,4(6):877-880
[reaction: see text] The thiazole C-nucleoside analogue was synthesized by the Hantzsch cyclization method to form the thiazole ring and was then converted to the thiazole N-oxide C-nucleoside analogue by peracid oxidation of the heterocycle nitrogen. Incorporation of the thiazole and thiazole N-oxide phosphoramidites into DNA was successful though significant deoxygenation of the N-oxide occurred during DNA assembly. The mechanism proposed for the reduction of the thiazole N-oxide to thiazole involves the formation of an N-oxide phosphite ester. 相似文献
2.
An efficient modified Hantzsch reaction is described for the synthesis of optically pure thiazole amino acid derivatives from the corresponding amino acids. The method is exemplified by the synthesis of a derivative of L-(Gln)Thz, the novel chiral thiazole amino acid moiety of dolastatin 3. The Cotton effects of thiazole amino acids correlate well with the absolute stereochemistry of these compounds. 相似文献
3.
[Reaction: see text] We report a one-step, racemization-free method for the diversification of peptide thiazoles via direct lithiation of the thiazole ring. The method is compatible with N-Boc, N-trityl, carboxylic ester, and carboxamide protecting groups and has been used to directly functionalize the thiazole ring of cyclopeptide natural products. 相似文献
4.
Yiqiang Li Huiqing Sun Jinli Xu Guangjun Xu Zan Su Jili Zhang 《International journal of environmental analytical chemistry》2016,96(10):921-928
A high-performance liquid chromatography with ultraviolet (HPLC-UV) detection method after derivatisation was developed for the first time for the novel fungicide zinc thiazole residue in tobacco samples. Field trials in two different locations were conducted to investigate the dissipation and residue of zinc thiazole in tobacco leaves and soil. The average recoveries of zinc thiazole were in the range of 82.5%–93.9% with relative standard deviations (RSDs) of 1.2%–9.1%. The zinc thiazole showed a rapid dissipation rate in fresh tobacco leaves with the half-lives of 1.1–1.6 days. The terminal residues of zinc thiazole in cured tobacco leaves and soil were 2.8–28.0 mg kg?1and <0.05 mg kg?1, respectively. The results could be used to establish the maximum residue limits (MRLs) and provide guidance for the scientific use of zinc thiazole in agriculture. 相似文献
5.
K. Arunkumar D. Naresh Kumar ReddyK.B. Chandrasekhar P. Rajender KumarK. Shiva Kumar Manojit Pal 《Tetrahedron letters》2012,53(30):3885-3889
Zeolite H-beta facilitated the reaction of α-chloro acetyl chloride with 1,2-bis-trimethyl silyl acetylene to give 1-chloro-4-(trimethylsilyl)but-3-yn-2-one which on treatment with thioacetamide afforded 2-methyl-4-[(trimethylsilyl)ethynyl]thiazole. l-Proline on the other hand facilitated the coupling reaction of 2-methyl-4-[(trimethylsilyl)ethynyl]thiazole with (hetero)aryl halides (modified Sonogashira reaction) under Pd-Cu catalysis in the presence of aqueous K2CO3 affording an improved method for the synthesis of corresponding 4-alkynyl substituted thiazole derivatives. 相似文献
6.
Synthesis of Heterocyclic Analogs of α‐aminoadipic Acid and its Esters Based on Imidazo[2,1‐b][1,3]Thiazole 下载免费PDF全文
Algirdas Šačkus Diana Bričkutė Osvaldas Paliulis Frank Abildgaard Sløk 《Journal of heterocyclic chemistry》2015,52(4):1032-1036
A method for the preparation of heterocyclic analogs of α‐aminoadipic acid and its esters based on the imidazo[2,1‐b][1,3]thiazole ring system was developed. In this method, free‐radical bromination of ethyl 6‐methylimidazo[2,1‐b][1,3]thiazole‐5‐carboxylate with NBS afforded a versatile building block, ethyl 6‐bromomethylimidazo[2,1‐b][1,3]thiazole‐5‐carboxylate. Coupling of ethyl 6‐bromomethylimidazo[2,1‐b][1,3]thiazole‐5‐carboxylate with Schöllkopf's chiral auxiliary followed by acidic hydrolysis generated ethyl 6‐[(2S)‐2‐amino‐3‐methoxy‐3‐oxopropyl]imidazo[2,1‐b][1,3]thiazole‐5‐carboxylate. A similar procedure using diethyl (Boc‐amino)malonate yielded racemic 2‐amino‐3‐[(5‐ethoxycarbonyl)imidazo[2,1‐b][1,3]thiazol‐6‐yl]propanoic acid. 相似文献
7.
An efficient palladium-catalyzed selective decarboxylation/C–H activation coupling of aryl acid with thiazole and oxazole under the assistance of 1,2,3-triazole ring were developed. This work provides an effective access to build functionalized 1,2,3-triazoles bearing thiazole and oxazole moieties. This method has good substrate compatibility to compose a series of selective heterocyclic compounds in moderate to good yields. 相似文献
8.
Trisubstituted thiazoles were synthesized with excellent yields using ligand-free, palladium-catalyzed, direct 5-arylation of 2,4-disubstituted thiazole and conventional or microwave-assisted heating. The palladium-catalyzed reaction yields were significantly influenced by LiCl additive, solvent, and heating method. The reaction times were reduced dramatically by employing microwave radiation instead of conventional heating. The synthetic methods can be applied to diverse 2,4,5-trisubstituted thiazoles by varying the aryl bromide and disubstituted thiazole reactants. 相似文献
9.
H. Demian Mioara Coman Ana Muresan I. Iovanov I. Simiti 《Journal of mass spectrometry : JMS》1978,13(9):504-509
The mass spectra of some 5-acetyl thiazoles were studied, and the differences emphasized between them and the corresponding 4-acetyl derivatives. This could constitute a method for their identification. The nature of the substituent in position 4 of the thiazole influences the fragmentation patterns of thiazole ring. In the case of 4-hydroxymethyl derivatives, a skeletal rearrangement occurs before fragmentation. 相似文献
10.
ZHAI Xin ZHAO Yan-fang WANG Jia HONG Wei HUANG Liang GONG Ping 《高等学校化学研究》2006,22(4):459-464
IntroductionOxazolidinones, exemplified by linezolid, are anovel class of totally synthetic antibacterial agents withactivities against a variety of clinically important sus-ceptible and resistant Gram-positive pathogenic bacteriasuch as methicillin-resis… 相似文献
11.
Chatterjee A Schroeder FC Jurgenson CT Ealick SE Begley TP 《Journal of the American Chemical Society》2008,130(34):11394-11398
Thiamin thiazole biosynthesis in eukaryotes is still not completely understood. In this report, a late intermediate, tightly bound to the active site of the Saccharomyces cerevisiae thiazole synthase, was identified as an adenylated thiazole tautomer. The reactivity of this unusual compound was evaluated. Its identification provides an additional molecular snapshot of the complex reaction sequence catalyzed by the eukaryotic thiazole synthase and identifies the final step of the thiamin-thiazole biosynthesis. 相似文献
12.
[reaction: see text] We herein report a new cobalt-catalyzed method for arylation of azole heteroarenes, including thiazole, oxazole, imidazole, benzothiazole, benzoxazole, and benzimidazole. The direct arylation of thiazole and oxazole was achieved both with iodo- and bromoarenes as the aryl donors in the presence of cobalt catalyst [Co(OAc)(2)/IMes] and cesium carbonate, while imidazole required the use of zinc oxide as the base. A complete reversal of arylation from C-5 to C-2 was accomplished using the bimetallic Co/Cu/IMes system. A direct comparison of the new cobalt method and the previously developed palladium protocol revealed significant differences, in terms of both chemical yield and selectivity. 相似文献
13.
Il’kin Vladimir G. Berseneva Vera S. Slepukhin Pavel А. Bakulev Vasiliy А. 《Chemistry of Heterocyclic Compounds》2018,54(12):1153-1160
Chemistry of Heterocyclic Compounds - A three-step method was designed and developed on the basis of retrosynthetic analysis for the synthesis of hybrid molecules containing a thiazole ring and an... 相似文献
14.
G. V. Zakharova R. R. Konstantinov A. V. Odinokov A. K. Chibisov M. V. Alfimov I. E. Kasheverov Yu. N. Utkin M. N. Zhmak V. I. Tsetlin 《High Energy Chemistry》2016,50(2):121-126
The paper presents the results of analysis of the effect of a high-affinity peptide (HAP) homologous to a fragment of the nicotinic acetylcholine receptor (nAChR) on the absorption and fluorescence spectra of thiazole orange and thioflavin T complexes with cucurbit[8]uril in aqueous solution. In the presence of HAP, a change in the absorption spectra of the dye complexes and a drop in the fluorescence intensity occur; for thiazole orange, the fluorescence intensity is restored to the initial level in the presence of α-bungarotoxin capable of high-affinity binding to nAChR. The proposed method make it possible to detect the presence of α-bungarotoxin. 相似文献
15.
On the basis of ZINDO program, we have designed a program to calculate the nonlinear second‐order polarizability βyk and βμ according to the SOS expression. The second‐order nonlinear optical properties of 4‐nitro‐4′‐dimethylamino‐stilbene and a series of its thiazole derivatives were studied. The calculated results were that: When replacing a benzene ring in 4‐nitro‐4′‐dimethylamino‐stilbene by a thiazole ring, the influence on β values depends on the position of thiazole ring. When the thiazole ring connects with nitro group (acceptor), the β values increase significantly compared with corresponding stilbene derivatives. The β values of 2‐(p‐donor‐β‐styryl)‐5‐nitro‐thiazole derivatives (2–7) are larger than those of 2‐(p‐nitro‐β‐styryl)‐5‐donor‐thiazole derivatives (8–13) and 2‐(p‐donor‐phenyl)‐azo‐5‐nitro‐thiazole derivatives (14–19). The 2‐(p‐donor‐β‐styryl)‐5‐nitro‐thiazole derivatives (2–7) are good candidates as chromophores duo to their high nonlinearities and potential good thermal stability. 相似文献
16.
Patellamide A was efficiently synthesized from thiazole 2 via two complementary heterocyclization approaches to form the thiazole and oxazoline rings. 相似文献
17.
A novel method for the construction of diheteroaryl thioethers from aromatic methyl ketones and thiourea is described. Iodine is the unique catalyst in this protocol. The transformation is free of foul-smell thiols and transition metal. In addition, this method could synthesize two thiazole rings and a sulfur bridge in one pot. 相似文献
18.
By a new tandem reaction, in which ethyl 1-pyrazolacetate reacted with carbon disulfide and iodomethane, pyrazolo[5,1-b]thiazole was synthesized. This was an easy method for the synthesis of this type of heterocyles. 相似文献
19.
Isha Mishra Raghav Mishra Somdutt Mujwar Phool Chandra Neetu Sachan 《Journal of heterocyclic chemistry》2020,57(6):2304-2329
Due to its appreciable diversity in biological actions, thiazole and its substituted components, a significant class of heterocyclic compounds has developed as an influential scaffold in the field of chemical sciences. The variability of thiazole core has been expressed through the effective instigation of its anticancer (Dasatinib, Tiazofurin), antiretroviral (Ritonavir, Brecanavir), antimicrobial (Sulfathiazole, Ravuconazole) and anti-inflammatory (Fenclozic acid, Meloxicam) derivatives. This reasonable diversity in the physiological reaction pattern led many scientists to refine and develop new structural alternatives with much more efficient pharmacological action. This review is crucial for previous studies and projects to survey the antimicrobial activity of thiazole and thiazole related compounds to the mid of 2019. 相似文献
20.
Extending the Substrate Scope of Bicyclic P‐Oxazoline/Thiazole Ligands for Ir‐Catalyzed Hydrogenation of Unfunctionalized Olefins by Introducing a Biaryl Phosphoroamidite Group 下载免费PDF全文
Maria Biosca Dr. Alexander Paptchikhine Dr. Oscar Pàmies Prof. Pher G. Andersson Prof. Montserrat Diéguez 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(8):3455-3464
This study identifies a series of Ir‐bicyclic phosphoroamidite–oxazoline/thiazole catalytic systems that can hydrogenate a wide range of minimally functionalized olefins (including E‐ and Z‐tri‐ and disubstituted substrates, vinylsilanes, enol phosphinates, tri‐ and disubstituted alkenylboronic esters, and α,β‐unsaturated enones) in high enantioselectivities (ee values up to 99 %) and conversions. The design of the new phosphoroamidite–oxazoline/thiazole ligands derives from a previous successful generation of bicyclic N‐phosphane–oxazoline/thiazole ligands, by replacing the N‐phosphane group with a π‐acceptor biaryl phosphoroamidite moiety. A small but structurally important family of Ir‐phosphoroamidite–oxazoline/thiazole precatalysts has thus been synthesized by changing the nature of the N‐donor group (either oxazoline or thiazole) and the configuration at the biaryl phosphoroamidite moiety. The substitution of the N‐phosphane by a phosphoroamidite group in the bicyclic N‐phosphane–oxazoline/thiazole ligands extended the range of olefins that can be successfully hydrogenated. 相似文献