共查询到20条相似文献,搜索用时 15 毫秒
1.
Adri van den Hoogenband Jos H.M. Lange Jack A.J. den Hartog Remco Henzen Jan Willem Terpstra 《Tetrahedron letters》2007,48(26):4461-4465
A highly efficient synthetic approach to novel 4-bromo-N-substituted oxindoles is described. The method involves a mild intramolecular copper-catalyzed amidation reaction of N-substituted 2,6-dibromophenylacetamides. In contrast to our recently published palladium-catalyzed amidation reaction, no concomitant dimerization on the 3-position of the formed oxindole occurs. 相似文献
2.
The Ugi four-component condensation between methyl o-formylbenzoates 1, anilines 2a-c, isocyanides 3, and trimethylsilyl azide (4) afforded the expected Ugi adducts 5a-d, which were cyclized to the title compounds 6a-d upon treatment with sodium ethoxide in ethanol. Starting from aralkyl- or alkylamines 2d-g the Ugi adducts underwent a spontaneous cyclization to tetrazolyl-isoindolinones 6e-j. 相似文献
3.
Ru-Ching Lian Meng-Hsuan Lin Pin-Hsuan Liao Jia-Jie Fu Meng-Ju Wu Yang-Chang Wu Fang-Rong Chang Chin-Chung Wu Po-Shen Pan 《Tetrahedron》2014
A four-component Ugi reaction (Ugi-4CR) utilizing formylphenyl boronic acids under mild condition was developed for the synthesis of arylboronic acid analogs. The reactions were performed in methanol and accelerated by microwave irradiation, which makes this strategy suitable for constructing boronic-containing chemical libraries. Two of the synthesized analogs were found to have cytotoxic activity against HepG2, MDA-MB231, and A549 cancer cell lines, demonstrating the potential application of this approach in developing novel boron-containing pharmaceuticals. 相似文献
4.
5.
Lukasz Porosa 《Tetrahedron letters》2009,50(28):4170-9119
A new form of enantioselective nitrogen arylation reaction is described. Beginning with symmetrical α-(2-bromobenzyl)malonamides, intramolecular palladium-catalyzed cross-coupling using a catalyst system including 3.3 mol % Pd(OAc)2 and 6.6 mol % of the chiral biaryl monophosphine (R)-MOP, desymmetrized quinolinone products are obtained in nearly quantitative yields in enantiomeric ratios up to 88:12. This Letter represents a rare example of enantioselective Buchwald-Hartwig reaction. 相似文献
6.
Radell Echemendía Olivia Fernández Julieta Coro Margarita Suárez Daniel G. Rivera 《Tetrahedron letters》2017,58(18):1784-1787
Aiming at developing a versatile method for the generation of hybrid heterocyclic molecules, we describe a sequential approach comprising the formation of carboxy-functionalized 1,3,5-thiadiazines followed by the Ugi reaction with variation of the amino and the isonitrile components. The method enables the generation of structurally diverse molecular hybrids including peptide, lipid, steroidal and sugar moieties linked to the 1,3,5-thiadiazine scaffold. 相似文献
7.
Roya Akbarzadeh 《Journal of organometallic chemistry》2010,695(21):2320-3424
An efficient and simple synthesis of ferrocenyl bis-amides by the Ugi four-component reaction of ferrocenecarboxaldehyde, carboxylic acids, isocyanides and amines in methanol at room temperature is reported. 相似文献
8.
A general method has been developed for the synthesis of N-substituted oxindoles. The two-step process involves initial microwave-assisted amide bond formation between 2-halo-arylacetic acids and various alkylamines and anilines, followed by a palladium-catalyzed intramolecular amidation under aqueous conditions. In the case of alkylamines, the procedure can be carried out as a one-pot process without isolation of the intermediate amide. [structure: see text] 相似文献
9.
Dehghan Negin Nasr-Isfahani Hossein Sarvary Afshin Bakherad Mohammad 《Monatshefte für Chemie / Chemical Monthly》2020,151(3):397-404
Monatshefte für Chemie - Chemical Monthly - A triple four-component Ugi reaction of isocyanide, amine, aldehyde, and trimesic acid as the acid component with three acidic functional groups in... 相似文献
10.
R. S. Borisov A. I. Polyakov L. A. Medvedeva N. I. Guranova L. G. Voskressensky 《Russian Chemical Bulletin》2012,61(8):1609-1615
Tetrazolo[1,5-a][1,4]benzodiazepines were obtained by an efficient azide five-centered four-component Ugi reaction, which used ketones, sodium azide, ammonium chloride, and the corresponding isonitrile. Scope and limitations of this multi-component reaction were considered. 相似文献
11.
A convenient, high yield procedure for the synthesis of anthranilic acids carrying a variety of different substituents as well as their straightforward transformation into the corresponding 9-chloroacridines could be established by using modified Buchwald-Hartwig amination conditions. 相似文献
12.
The rapid and efficient synthesis of various 2,6-disubstituted-3-amino-imidazopyridines using a microwave-assisted one-pot cyclization/Suzuki coupling approach is described. The utility of a 2-aminopyridine-5-boronic acid pinacol ester as a robust and versatile building block for the synthesis of diverse compound libraries is emphasized. The boronate functional group is remarkably tolerant to the Lewis acid catalyzed cyclizations, and the subsequent Pd(0)-catalyzed Suzuki coupling reactions proceed cleanly in the presence of magnesium salts. This work highlights the vast potential of microwave-assisted, metal-catalyzed, multicomponent reactions. 相似文献
13.
Maciej Dawidowski Franciszek Herold Marcin Wilczek Jadwiga Turło Andrzej Chodkowski Anna Gomółka Jerzy Kleps 《Tetrahedron》2012,68(39):8222-8230
A three-step sequence involving an Ugi five-center, four-component reaction (U-5C-4CR), amide N-detertbutylation and cyclocondensation has been developed for easy access to diverse bicyclic 2,6-diketopiperazine (2,6-DKP) derivatives. In the key step, aromatic aldehydes were successfully coupled with cyclic α-amino acids and isocyanides in the course of U-5C-4CR. Boron trifluoride-acetic acid complex was developed as a new N-detertbutylating agent effective at rt. 相似文献
14.
Diastereoselective double Heck cyclizations of cyclohexene diamides 1 and 3 form contiguous quaternary stereocenters, with diastereoselection being controlled by the trans-diol protecting group. In this, the first in a series of two papers, the origin of diastereoselection in the first ring-closure step of these reactions is examined. Nine simplified analogues of 1 and 3 were synthesized and cyclized to discern what structural features are required to realize high diastereoselection in the first intramolecular Heck reaction. These studies show that high stereoselection (>20:1) does not arise from a single structural feature: it is seen only in substrates that contain both a trans-acetonide and a tertiary amide substituent at C2. Two subtle factors appear to be involved: (1) Avoidance of eclipsing interactions between the forming C-C bond and the pseudoaxial hydrogen atom at C6 and between the pseudoequatorial hydrogen atom at C6 and the carbonyl carbon of the forming spirooxindole. (2) The vinylic amide substituent that is not involved in the insertion event preferentially adopts a perpendicular conformation, placing the sterically bulky NR(2) over the alkene pi bond. syn-Pentane-like interactions between this substituent and the C3 of the cyclohexene are avoided in the favored insertion topography. These two effects, when combined, produce a highly diastereoselective process. 相似文献
15.
An efficient method is developed to construct drug-like 2,3-dihydropyrazino[1,2-a]indole-1,4-diones from 1H-indole-2-carboxylic acids, ethyl pyruvate, isocyanides, and primary amines via a one-pot, two-step procedure involving Ugi reaction and microwave-assisted cyclization. 相似文献
16.
In the presence of a Lewis acid the phenol-Passerini three-component reaction (phenol-P-3CR) system is found to deliver a product of the phenol-Ugi four-component reaction (phenol-U-4CR). It is the first demonstration of an isocyanide as an amine equivalent in isocyanide-based multicomponent reactions (IMCRs). In general, by using Ti(O-i-Pr)4 in MeOH both phenol-U-4CR and U-4CR products are synthesized from an aromatic aldehyde, a phenolic or carboxylic acid, and an isocyanide. Moreover, by using MeCN as the solvent, the phenol-P-3CR products can be obtained in good yields without contamination of the phenol-U-4CR products. 相似文献
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18.
Morteza Shiri Mohammad Ali Zolfigol Ardeshir Khazaei Toktam Faal-Rastegar Hendrik G. Kruger 《Journal of the Iranian Chemical Society》2014,11(1):85-90
Multicomponent condensation of ethyl 3-formylindole 2-carboxylate, amines, isocyanide and (S)-N-boc-alanine or (S)-N-boc-serine is described. This Ugi four-component condensation (Ugi-4CC) reaction yielded a series of novel dipeptides containing an indolyl moiety. These compounds exhibit potential biological activity. 相似文献
19.
From readily available allylamine, aldehyde and isocyanoacetamide, a three-component reaction followed by a Pummerer cyclization provided tetracyclic ring systems (6-7-5-6 and 6-6-5-6) in excellent overall yields. 相似文献