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1.
Copper and silver N‐heterocyclic carbene (NHC) complexes were prepared through a simple, base‐free protocol involving the decomposition of corresponding imidazol(in)ium‐2‐carboxylates under thermolytic conditions and a subsequent reaction of the in situ generated carbenes with copper(I) or silver(I) chloride, respectively. The desired NHC metal complexes were isolated with good yields after simple crystallization. 相似文献
2.
Jarle Holt Freddy Tjoss Jan M. Bakke Anne Fiksdahl 《Journal of heterocyclic chemistry》2004,41(6):987-989
The nitro group of methyl 3‐nitropyridine‐4‐carboxylate ( 1 ) has successfully been replaced by nitrogen, oxygen and sulphur nucleophiles by nucleophilic aromatic substitution to give the 3‐azido, 3‐methoxy, 3‐phenoxy and 3‐thiophenoxypyridine‐4‐carboxylates ( 2a — d ). 相似文献
3.
M. V. Chudinov A. V. Matveev N. I. Zhurilo A. N. Prutkov V. I. Shvets 《Journal of heterocyclic chemistry》2015,52(5):1273-1277
An efficient general route to the synthesis of 5‐substituted 1H‐1,2,4‐triazole‐3‐carboxylates was developed. N‐acylamidrazones were obtained from carboxylic acid hydrazides and ethyl thiooxamate or ethyl 2‐ethoxy‐2‐iminoacetate hydrochloride and then were reacted with chloroanhydride of the same carboxylic acid. As the next step, diacylamidrazones were cyclized to 5‐substituted 1H‐1,2,4‐triazole‐3‐carboxylates one pot in mild conditions. 相似文献
4.
A Facile Approach to Optically Active Hydroquinoline‐2‐carboxylates by a One‐Pot Asymmetric Michael/Transamination/Cyclization Process
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Dr. Chao Rong Hongjie Pan Dr. Mao Liu Hua Tian Dr. Yian Shi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(9):2887-2891
An efficient one‐pot synthesis of optically active hydroquinoline‐2‐carboxylates from 1,3‐cyclohexanediones, β,γ‐unsaturated α‐keto ester, and benzylamine in the presence of a chiral base catalyst and 1,8‐diazabicyclo[5.4.0]undec‐7‐ene (DBU) with good diastereoselectivity and high enantioselectivity is described. The reaction proceeds by a sequential asymmetric Michael/transamination/cyclization process. 相似文献
5.
Makoto Shimizu Haruna Katsurayama Isao Mizota Yusong Zhu 《Journal of heterocyclic chemistry》2019,56(9):2479-2486
Synthesis of 2‐methyl‐3‐oxoindoline‐2‐carboxylates is developed using a bis(trimethylsilyl)aluminum chloride‐induced aza‐Brook rearrangement as a crucial step. Regarding the organoaluminum species, use of readily available tris(trimethylsilyl)aluminum·ether complex was not suitable for the present cyclization. After a series of examination of the reaction conditions, the aza‐Brook rearrangement and the subsequent cyclization with 2 equivalens of bis(trimethylsilyl)aluminum chloride were found to be the most effective. An application to the synthesis of a potential intermediate of duocarmycin A is also described, in which ozonolysis of the styrenyl moiety and the Barton–McCombie deoxygenation of the hydroxymethyl group were successfully carried out. 相似文献
6.
A. Shafiee J. Shahbazi Mojarrad M. A. Jalili H. R. Adhami F. Hadizadeh 《Journal of heterocyclic chemistry》2002,39(2):367-373
Starting from readily available p‐substituted‐benzylamines a series of ethyl 2‐alkylthio‐1‐substituted‐ben‐zylpyrrolo[2,3‐d]imidazole‐5‐carboxylates was prepared. In addition, starting from 2‐alkyl‐4(or 5)‐formylimidazoles and methyl 4′‐bromomethylbiphenyl‐2‐carboxylate a series of methyl substituted‐pyrrolo[2,3‐d]imidazole‐5‐carboxylates and methyl substituted‐pyrrolo[3,2‐d]imidazole‐5‐carboxylates was prepared. 相似文献
7.
Oxidative Asymmetric Aza‐Friedel–Crafts Alkylation of Indoles with 3‐Indolinone‐2‐carboxylates Catalyzed by a BINOL Phosphoric Acid and Promoted by DDQ
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An asymmetric aza‐Friedel–Crafts alkylation reaction between indoles and indolenines that were derived in situ from 3‐indolinone‐2‐carboxylates has been developed by using 3,3′‐bis(triphenylsilyl)‐1,1′‐binaphthyl‐2,2′‐diyl hydrogen phosphate as a catalyst. The reaction proceeded under mild conditions and provided chiral indol‐3‐yl‐3‐indolinone‐2‐carboxylate derivatives in good yields with excellent ee values (up to 98.6 %). Similarly, the Mannich‐type addition of indoline‐3‐ones to indolenines provided heterodimers with vicinal chiral quaternary centers. This method was successfully applied to the construction of the core structure of trigonoliimine C. 相似文献
8.
Alkyl 3‐(alkylamino)‐5,6‐dicyanopyrazine‐2‐carboxylates and alkyl 3‐(alkylamino)quinoxaline‐2‐carboxylates were obtained in good yields by treatment of Nef‐isocyanide adducts with 1,2‐diamines in MeCN. 相似文献
9.
Joseph Becica Oliver R. J. Heath Cameron H. M. Zheng David C. Leitch 《Angewandte Chemie (International ed. in English)》2020,59(39):17277-17281
Carboxylate esters have many desirable features as electrophiles for catalytic cross‐coupling: they are easy to access, robust during multistep synthesis, and mass‐efficient in coupling reactions. Alkenyl carboxylates, a class of readily prepared non‐aromatic electrophiles, remain difficult to functionalize through cross‐coupling. We demonstrate that Pd catalysis is effective for coupling electron‐deficient alkenyl carboxylates with arylboronic acids in the absence of base or oxidants. Furthermore, these reactions can proceed by two distinct mechanisms for C?O bond activation. A Pd0/II catalytic cycle is viable when using a Pd0 precatalyst, with turnover‐limiting C?O oxidative addition; however, an alternative pathway that involves alkene carbopalladation and β‐carboxyl elimination is proposed for PdII precatalysts. This work provides a clear path toward engaging myriad oxygen‐based electrophiles in Pd‐catalyzed cross‐coupling. 相似文献
10.
Franziska Bendrath Zharylkasyn A. Abilov Abiodun Falodun Martin Hein Alexander Villinger Peter Langer 《Helvetica chimica acta》2013,96(12):2185-2190
5‐(2‐Cyanoethyl)‐1,1′‐biphenyl‐2‐carboxylates were prepared by regioselective formal [3+3] cyclocondensations of 1,3‐bis[(trimethylsilyl)oxy]buta‐1,3‐dienes. 相似文献
11.
OrazioA. Attanasi Lucia DeCrescentini Paolino Filippone Fabio Mantellini Stefania Santeusanio 《Helvetica chimica acta》2001,84(8):2379-2386
3‐{[(tert‐Butoxy)carbonyl]diazenyl}but‐2‐enoates react in tetrahydrofuran at room temperature with aromatic 1,2‐diamines to give 3‐methylquinoxaline‐2‐carboxylates. These products were also obtained in solid‐phase synthesis, by using polymer‐bound 3‐diazenylbut‐2‐enes. 相似文献
12.
Yoshihisa Kurasawa Kazunori Sakurai Shinnosuke Kajiwara Kazuho Harada Yoshihisa Okamoto Ho Sik Kim 《Journal of heterocyclic chemistry》2000,37(5):1257-1263
The reaction of the 2‐(1‐alkylhydrazino)‐6‐chloroquinoxaline 4‐oxides 1a,b with diethyl acetone‐dicarboxylate or 1,3‐cyclohexanedione gave ethyl 1‐alkyl‐7‐chloro‐3‐ethoxycarbonylmethylene‐1,5‐dihydropyridazino[3,4‐b]quinoxaline‐3‐carboxylates 5a,b or 6‐alkyl‐10‐chloro‐1‐oxo‐1,2,3,4,6,12‐hexahydroquinoxalino[2,3‐c]cinnolines 7a,b , respectively. Oxidation of compounds 5a,b with nitrous acid afforded the ethyl 1‐alkyl‐7‐chloro‐3‐ethoxycarbonylmethylene‐4‐hydroxy‐1,4‐dihydropyridazino‐[3,4‐b]quinoxaline‐4‐carboxylates 9a,b , whose reaction with base provided the ethyl 2‐(1‐alkyl‐7‐chloro‐4‐oxo‐1,4‐dihydropyridazino[3,4‐b]quinoxalin‐3‐yl)acetates 6a,b , respectively. On the other hand, oxidation of compounds 7a,b with N‐bromosuccinimide/water furnished the 4‐(1‐alkyl‐7‐chloro‐4‐oxo‐1,4‐dihydropyridazino[3,4‐b]quinoxalin‐3‐yl)butyric acids 8a,b , respectively. The reaction of compound 8a with hydroxylamine gave 4‐(7‐chloro‐4‐hydroxyimino‐1‐methyl‐1,4‐dihydropyridazino[3,4‐b]quinoxalin‐3‐yl)‐butyric acid 12 . 相似文献
13.
Herein, we describe an environmentally benign and cost‐effective protocol for the synthesis of valuable bifuranyl dicarboxylates, starting with α‐bromination of readily accessible furan‐2‐carboxylates by LiBr and K2S2O8. Furthermore, the bromination intermediate product 5‐bromofuran‐2‐carboxylates were then conducted in a palladium‐catalyzed reductive homocoupling reactions in the presence of alcohols to afford bifuranyl dicarboxylates. One of the final products in this protocol, [2,2’]bifuran‐5,5’‐dicarboxylic acid esters, are essential monomers of poly(ethylene bifuranoate), which can be served as an green and versatile alternative polymer for traditional poly(ethylene terephthalate) that is currently common in technical plastics. 相似文献
14.
Ali Souldozi Ali Ramazani Ali Reza Dadrass Katarzyna Ślepokura Tadeusz Lis 《Helvetica chimica acta》2012,95(2):339-348
The reaction between secondary amines, benzoyl isothiocyanate, and dialkyl acetylenedicarboxylates (=dialkyl but‐2‐ynedioates) in the presence of silica gel (SiO2) led to alkyl 2‐(dialkylamino)‐4‐phenylthiazole‐5‐carboxylates in fairly high yields. The structures of the products were confirmed by their IR, 1H‐ and 13C‐NMR, and mass spectra, and by a single‐crystal X‐ray structure determination. 相似文献
15.
3‐Arylamino‐4‐ethoxycarbonylisoxazol‐5(2H)‐ones, substituted on nitrogen with a benzothiazole group, reacts with triethylamine in ethanol under reflux conditions to provide a convenient synthesis of ethyl 2‐aryl‐aminoimidazo[2,1‐b]benzothiazole‐3‐carboxylates. 相似文献
16.
Visible‐Light‐Driven Intermolecular [2+2] Cycloadditions between Coumarin‐3‐Carboxylates and Acrylamide Analogs
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Prof. Dr. Qiang Liu Fu‐Ping Zhu Prof. Dr. Xiao‐Ling Jin Xiao‐Ju Wang Han Chen Prof. Dr. Li‐Zhu Wu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(29):10326-10329
This paper reports a room temperature visible‐light‐driven protocol for the intermolecular [2+2] cycloadditions between coumarin‐3‐carboxylates and acrylamides analogs by an energy‐transfer process. Using an iridium complex FIrPic as a photosensitizer and a 3 W blue LED as a light source, an array of cyclobutabenzocypyranones were prepared in moderate to excellent yields. 相似文献
17.
Bhimapaka China Raju Gannerla Saidachary Jaladi Ashok Kumar Balasubramanian Sridhar 《Helvetica chimica acta》2011,94(2):248-253
Ethyl 2‐(chloromethyl)‐2‐hydroxy‐2H‐chromene‐3‐carboxylates 2a – 2j have been synthesized by reaction of substituted salicylaldehydes with ethyl 4‐chloro‐3‐oxobutanoate, in the presence of piperidine in CH2Cl2 at room temperature, in good yields. 相似文献
18.
Dr. Liangbin Huang Dagmar Hackenberger Prof. Dr. Lukas J. Gooßen 《Angewandte Chemie (International ed. in English)》2015,54(43):12607-12611
In the presence of catalytic [{IrCp*Cl2}2] and Ag2CO3, Li2CO3 as the base, and acetone as the solvent, benzoic acids react with arenediazonium salts to give the corresponding diaryl‐2‐carboxylates under mild conditions. This C? H arylation process is generally applicable to diversely substituted substrates, ranging from extremely electron‐rich to electron‐poor derivatives. The carboxylate directing group is widely available and can be removed tracelessly or employed for further derivatization. Orthogonality to halide‐based cross‐couplings is achieved by the use of diazonium salts, which can be coupled even in the presence of iodo substituents. 相似文献
19.
One‐Pot Synthesis of Highly Substituted 1H‐Pyrazole‐5‐carboxylates from 4‐Aryl‐2,4‐diketoesters and Arylhydrazines
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Jiao‐Jiao Zhai Chun‐Hui Gu Ying Guo Dao‐Hua Liao Dun‐Ru Zhu Ya‐Fei Ji 《Journal of heterocyclic chemistry》2016,53(3):840-848
A one‐pot synthesis of highly substituted 1H‐pyrazole‐5‐carboxylates 1 has been developed starting from easily available 4‐aryl‐2,4‐diketoesters 2 and arylhydrazine hydrochlorides 3 . More active 2‐carbonyl group of 2 was blocked with methoxyamine hydrochloride to give 2‐methoxy imine intermediates, which were then subjected to condensation cyclization with 3 in situ to provide the desired products 1 . In addition, the geometrical configuration of 1aa was unambiguously confirmed by single crystal X‐ray crystallography. 相似文献
20.