共查询到20条相似文献,搜索用时 328 毫秒
1.
Glen W. Spears Kiyoshi Tsuji Takashi Tojo Hiroaki Nishimura Takashi Ogino 《Journal of heterocyclic chemistry》2002,39(4):799-804
The novel title compounds have been prepared in high yield by an optimized amide coupling followed by a Dieckmann cyclization. Additionally, this new route is amenable to preparative scale synthesis. 相似文献
2.
《Journal of heterocyclic chemistry》2017,54(2):1261-1266
This article describes an efficient approach for the synthesis of 5‐amino‐3‐methyl‐7‐aryl‐1,3‐dihydroisobenzofuran‐4,6‐dicarbonitrile derivatives from the reaction of aromatic aldehyde, 2‐methyltetrahydrofuran‐3‐one, and malononitrile under mild conditions. This is a simple and facile process to structure this important heterocyclic compounds. The other advantages of this approach are rapid reaction rate, high yield, and simple procedure. This article provided a good method for the synthesis of 1,3‐dihydroisobenzofuran derivatives. 相似文献
3.
M. Todd Hovey Dr. Christopher T. Check Alexandra F. Sipher Prof. Karl A. Scheidt 《Angewandte Chemie (International ed. in English)》2014,53(36):9603-9607
A convergent and efficient transition‐metal‐free catalytic synthesis of 2‐aryl‐indoles has been developed. The interception of a highly reactive and transient aza‐ortho‐quinone methide by an acyl anion equivalent generated through N‐hetereocyclic carbene catalysis is central to this successful strategy. High yields and a wide scope as well as the streamlined synthesis of a kinase inhibitor are reported. 相似文献
4.
Radomyr V. Smaliy Aleksandra A. Chaykovskaya Nataliya A. Shtil Aleksandr S. Savateev Aleksandr N. Kostyuk 《Heteroatom Chemistry》2013,24(2):146-151
In this work, possible approaches to the synthesis of 1,2,5‐substituted 4‐phosphoryl‐3‐formylpyrroles have been considered. As a result, two methods for the synthesis of 4‐(diphenylphosphoryl)‐1‐(4‐ethoxyphenyl)‐2,5‐dimethyl‐1H‐pyrrole‐3‐carbal‐dehyde were proposed; the highest yields gives formylation of 3‐(diphenylphosphorothioyl)‐1‐(4‐ethoxyphenyl)‐2,5‐dimethyl‐1H‐pyrrole. The formyl fragment was successfully converted into a Schiff base with phenethylamine, and the phosphoryl group has been reduced to phosphine with silicochloroform, which suggests a promising approach to the synthesis of chiral bidentate phosphine ligands. © 2013 Wiley Periodicals, Inc. Heteroatom Chem 24:146–151, 2013; View this article online at wileyonlinelibrary.com . DOI 10.1002/hc.21069 相似文献
5.
Shuanglin Qin Yuting Cao Yunhao Luo Shende Jiang J. Stephen Clark Xiaoji Wang Guang Yang 《Helvetica chimica acta》2019,102(7)
In this article, we report the rapid and facile synthesis of chiral 3‐methyl‐2,5‐trans‐tetrahydrofurans. This reaction utilizes cheap and easily available starting materials. A domino hydrolysis and intramolecular Michael‐type ring closure reaction was the key step. As a result, synthesis of the desired 3‐methyl‐2,5‐trans‐tetrahydrofurans could be achieved in gram‐scale over seven linear steps with high chemical yield and high diastereoselectivity. 相似文献
6.
Aziridines are highly useful compounds as building blocks for the synthesis of important organic compounds. Amino acid synthesis by aziridine ring opening reaction is a good example to the use of aziridines. Although this reaction is studied by many groups, the synthesis of amino phosphonic acids is less explored. In this study, we have carried out the ring opening reaction of aziridinyl phosphonates with a variety of alcohols including the more functional propargylic and allylic alcohols. These reactions provided functionalized α‐amino‐β‐alkoxyphosphonates in 40–91 % yield. 相似文献
7.
Wen‐Yong Han Zun‐Ting Zhang Ying‐Chun Zhang Dong Xue Gang Li 《Helvetica chimica acta》2010,93(8):1641-1649
A simple and straightforward methodology toward the synthesis of novel 1‐(4,5‐diphenylpyrimidin‐2‐yl)thiourea has been developed by a one‐step reaction of isoflavones with amidinothiourea. A series of 16 new compounds was synthesized. All compounds were characterized by FT‐IR, NMR, and elemental analysis. The structure of a typical compound was established by X‐ray diffraction. A variety of substrates can participate in the process with good yields and high purities, making this methodology suitable for library synthesis in drug discovery. 相似文献
8.
Ruthenium‐Catalyzed Multicomponent Reactions: Access to α‐Silyl‐β‐Hydroxy Vinylsilanes,Stereodefined 1,3‐Dienes,and Cyclohexenes 下载免费PDF全文
Prof. Dr. Barry M. Trost Dr. Dennis C. Koester Dr. Ehesan U. Sharif 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(8):2634-2638
The synthesis of densly functionized α‐silyl‐β‐hydroxyl vinylsilanes via ruthenium‐catalyzed multicomponent reaction (MCR) is reported herein. Exceptionally high regio‐ and diastereoselectivity was achieved by employing an unprecedented hydrosilylation of bifunctional silyl‐propargyl boronates. The simple protocol, mild reaction conditions, and unique tolerability of this method make it a valuable tool for the synthesis of highly elaborated building blocks. The one‐pot synthesis of stereodefined olefins, the generation of a valuable cyclohexene building block through a four‐component MCR, and further functionalization in an abundance of diastereoselective reactions is disclosed herein. 相似文献
9.
Joshua Britton Jared W. Castle Prof. Gregory A. Weiss Prof. Colin L. Raston 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(31):10773-10776
Inspired by nature's ability to construct complex molecules through sequential synthetic transformations, an assembly line synthesis of α‐aminophosphonates has been developed. In this approach, simple starting materials are continuously fed through a thin‐film reactor where the intermediates accrue molecular complexity as they progress through the flow system. Flow chemistry allows rapid multistep transformations to occur via reaction compartmentalization, an approach not amenable to using conventional flasks. Thin film processing can also access facile in situ solvent exchange to drive reaction efficiency, and through this method, α‐aminophosphonate synthesis requires only 443 s residence time to produce 3.22 g h?1. Assembly‐line synthesis allows unprecedented reaction flexibility and processing efficiency. 相似文献
10.
Tuan P. Tran Edmund L. Ellsworth Brian M. Watson Joseph P. Sanchez H. D. Hollis Showalter John R. Rubin Michael A. Stier Judy Yip Dai Q. Nguyen Paul Bird Rajeshwar Singh 《Journal of heterocyclic chemistry》2005,42(4):669-674
A new synthesis of a series of 3‐amino‐1H‐quinazoline‐2,4‐diones is described. The 1H‐quinazoline‐2,4‐dione 10 was made starting with fluorobenzoic acid in three high yielding steps. The key step of this synthesis involved the generation of the dianion of urea 7 and the subsequent intramolecular nucleophilic displacement of the 2‐fluoro to form the quinazolinedione ring. The 3‐amino moiety was incorporated using (2,4‐dinitro‐phenyl)‐hydroxylamine as the aminating reagent. 相似文献
11.
A new solid‐phase approach for the synthesis of 2‐amido‐1,3,4‐oxadiazoles has been developed. In this synthesis, hydroxypentyl JandaJel polymer support was treated with excess of oxalyl chloride to give resin‐bound 2‐chloro‐2‐oxoacetate, and this intermediate was then coupled with different hydrazides to give resin‐bound 2‐(N′‐acylhydrazinyl)‐2‐oxoacetate. Intramolecular dehydrative cyclization of resulting resin‐bound linear precursor followed by direct amidation using aluminum amide reagent provided 5‐substituted 1,3,4‐oxadiazoles as 2‐carboxamides. To explore the scope of this reaction sequence, we synthesized a small set of library using a combination of hydrazides and amines, and the desired products were obtained in good to high yields. 相似文献
12.
Dr. Jérôme Jacq Dr. Patrick Pasau 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(38):12223-12233
1,2,3‐Triazole has become one of the most important heterocycles in contemporary medicinal chemistry. The development of the copper‐catalyzed Huisgen cycloaddition has allowed the efficient synthesis of 1‐substituted 1,2,3‐triazoles. However, only a few methods are available for the selective preparation of 2‐substituted 1,2,3‐triazole isomers. In this context, we decided to develop an efficient flow synthesis for the preparation of various 2‐aryl‐1,2,3‐triazoles. Our strategy involves a three‐step synthesis under continuous‐flow conditions that starts from the diazotization of anilines and subsequent reaction with malononitrile, followed by nucleophilic addition of amines, and finally employs a catalytic copper(II) cyclization. Potential safety hazards associated with the formation of reactive diazonium species have been addressed by inline quenching. The use of flow equipment allows reliable scale up processes with precise control of the reaction conditions. Synthesis of 2‐substituted 1,2,3‐triazoles has been achieved in good yields with excellent selectivities, thus providing a wide range of 1,2,3‐triazoles. 相似文献
13.
Taku Sakaguchi Toyoharu Kobayashi Dr. Sho Hatano Hiroshi Tsuchikawa Dr. Koichi Fukase Prof. Dr. Katsunori Tanaka Dr. Shigeo Katsumura Prof. Dr. 《化学:亚洲杂志》2009,4(10):1573-1577
An efficient one‐pot synthetic procedure for the synthesis of 2,4‐disubstituted pyridines has been successfully established. The method proceeds through a 6π‐azaelectrocyclization‐aromatization sequence. Using this method, a wide variety of pyridine structures substituted at the 2‐position have been rapidly constructed from vinyl stannanes, vinyl iodide, sulfonamide, and a palladium catalyst. The method was further applied to the solid‐phase synthesis wherein the use of a “traceless” sulfonamide linker enabled the rapid preparation of a small library of pyridines with high purity, without any chromatographic separation. 相似文献
14.
Hiroshi Tanaka Tsuyoshi Hasegawa Narumi Kita Hiroko Nakahara Takahiro Shibata Sho Oe Makoto Ojika Koji Uchida Takashi Takahashi 《化学:亚洲杂志》2006,1(5):669-677
An efficient solution‐phase synthesis of rac‐15‐deoxy‐Δ12,14‐PGJ2 (15dPGJ2) derivatives that contain variable α and ω chains based on a polymer‐assisted strategy and their neurite‐outgrowth‐promoting activity are described. The strategy for the synthesis of PGJ2 derivatives involves the use of a vinyl iodide bearing cyclopentenone as a key intermediate, which undergoes Suzuki–Miyaura coupling and subsequent Lewis acid catalyzed aldol condensation for incorporation of the ω and α chains, respectively. For easy access to the PGJ2 derivatives, a polymer‐supported catalyst and scavengers were adapted for use in these four diverse steps, in which workup and purification can be performed by simple filtration of the solid‐supported reagents. By using this methodology, we succeeded in the synthesis of 16 PGJ2 derivatives with four alkyl boranes and four aldehydes. The neurite‐outgrowth‐promoting activity of the 16 synthetic compounds in PC12 cells revealed that the side‐chains play a major role in modulating their biological activity. The carboxylic acid on the α chain improved the biological activity, although it was not absolutely required. Furthermore, a PGJ2 derivative with a phenyl moiety on the ω chain was found to exhibit an activity comparable to that of natural 15dPGJ2. 相似文献
15.
《Helvetica chimica acta》2017,100(11)
Two pathways were developed and investigated for the synthesis of the ‘aged’‐nonapeptide nerve‐agent bioadduct of human butyrylcholinesterase (BuChE). Considering the fast ageing of nerve‐agent adducts of BuChE in patients and biomedical samples this target molecule is of paramount relevance for quantitative analysis with respect to the Chemical Weapons Convention. Two approaches using a precursor bearing a hydroxyl on its phosphonyl moiety and a benzyl protected precursor were considered. Several impurities were identified and circumvented during the optimization of the peptide synthesis step. The ‘aged’‐nonapeptide adduct was successfully synthesized by solid‐phase‐peptide‐synthesis (SPPS ). 相似文献
16.
Yun‐Zhou Zhao Hai‐Bin Yang Prof. Dr. Xiang‐Ying Tang Prof. Dr. Min Shi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(9):3562-3566
RhII‐catalyzed intermolecular [3+2] cycloaddition of 2 H‐azirines with N‐sulfonyl‐1,2,3‐triazoles is disclosed, in which a series of fully functionalized pyrroles is produced via rhodium azavinyl carbene intermediates. A distinct feature of this reaction is that the azavinyl carbene serves as a [2 C] equivalent, instead of as [1 C] or aza‐[3 C] synthons, which have been reported previously in cyclopropanations and [3+n] cycloadditions. Moreover, this methodology has also been successfully applied in the total synthesis of URB447 as well as the formal synthesis of Atorvastatin (Lipitor). 相似文献
17.
Yingcai Wang Gang Liu Jeremy Chris P. Reyes Randolph Duverna 《Journal of heterocyclic chemistry》2015,52(4):1185-1191
A versatile synthesis of 3‐cyano‐2‐pyridones via a one‐pot, four‐component condensation of ethyl cyanoacetate, ketones, aldehydes, and ammonium acetate under very mild conditions has been developed. This method provides rapid access to this type of valuable heterocyclic compounds from readily available materials in a single operation. 相似文献
18.
19.
Kavitha Kotthireddy Srikrishna Devulapally Pramod Kumar Dubey Aparna Pasula 《Journal of heterocyclic chemistry》2019,56(3):938-946
A facile, convenient, and adequate method has been developed for the synthesis of novel 5‐amino‐3‐(2‐oxo‐2H‐chromen‐3‐yl)‐7‐aryl‐7H‐thiazolo[3,2‐a]pyridine‐6,8‐dicarbonitriles ( 6 ) by employing 2‐(4‐(2‐oxo‐2H‐chromen‐3‐yl)thiazol‐2‐yl)acetonitrile ( 3 ) as an important precursor. Initially, we have synthesized the target compounds in a stepwise manner and then approached a tandem method to examine the feasibility of one‐pot method. Subsequently, one‐pot three‐component protocol has been established for the synthesis of title compounds by the reaction of 3 with benzaldehyde and malononitrile in refluxing ethanol engender a new six‐membered thiazolo[3,2‐a] pyridine as a hybrid scaffold. Reaction conditions were optimized for this reaction and a broad substrate scope with various aryl and heteroaryl aldehydes make this protocol very practical, attractive, and worthy. Mechanistic aspects for the formation of these compounds were outlined comprehensively. Characterization of these newly synthesized compounds was achieved by means of IR, 1H NMR, 13C NMR, and HRMS. 相似文献
20.
Synthesis of Thiophene‐Based π‐Conjugated Oligomers via Ligand‐Enabled Pd‐Catalyzed Suzuki–Miyaura Coupling of Haloterthienyls 下载免费PDF全文
Jie Guo Yong Wu Prof. Dr. Fuk Yee Kwong Dr. Heng Zhang Prof. Dr. Aiwen Lei 《化学:亚洲杂志》2018,13(13):1660-1663
A ligand‐enabled Pd‐catalyzed Suzuki–Miyaura coupling of haloterthienyls for the synthesis of various thiophene‐based π‐conjugated oligomers including quinquethiophenes is demonstrated. An indolyl phosphine ligand plays an important role in this transformation. Thiopheneboronic acids were well applied, which might open up a window for the application of thiopheneboronic acids in the synthesis of thiophene‐based π‐conjugated oligomers in materials chemistry. 相似文献