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1.
Nucleophilic phosphorus add to tetraethyl ethylidene diphosphonate in protic solvent to yield the product of the Michael reaction. This reaction appeared to be reversible at a temperature upper than 160 °C. To avoid this reverse reaction, alkylation in α position of the two phosphonate functions by activated elecrophile is reported. 相似文献
2.
Facile Michael addition of active methylene compounds to α,Β-unsaturated carbonyl compounds takes place on the surface of
potassium carbonate under microwave irradiation. Further studies on microwave-mediated Robinson annulations reveal a convenient
and facile method for condensation of chalcone with methylene compounds to furnish cyclohexenones. 相似文献
3.
Jialing Xian Lin Chen Ling Ye Yin Sun Zhichuan Shi Zhigang Zhao Xuefeng Li 《Tetrahedron》2019,75(15):2350-2356
A highly enantioselective (49–99% ee) Michael addition/lactonization cascade process has been developed to construct 3,4-dihydropyran-2-one in the presence of a bifunctional squaramide. Various α,β-unsaturated N-acyl heterocycles were well tolerated and afforded 3,4-dihydropyran-2-ones in moderate to excellent isolated yields (50–99%). Both cyclic and acyclic β-diketones functioned as appropriate donors. The resulting 3,4-dihydropyran-2-ones could be readily converted into oxadecalinones. 相似文献
4.
Péter Bakó Zsolt RapiGyörgy Keglevich Tamás SzabóPéter L. Sóti Tamás VíghAlajos Gr?n Tamás Holczbauer 《Tetrahedron letters》2011,52(13):1473-1476
Liquid-liquid phase asymmetric Darzens condensations were promoted by d-glucose- and d-mannose-based crown ethers. The corresponding aromatic and heteroaromatic α,β-epoxyketones were obtained with moderate to high enantioselectivities (up to 96%) as well as diastereoselectivities (up to 98:2) under mild reaction conditions. The absolute configurations of several of the epoxyketones were determined by single crystal X-ray analysis. The Michael additions of diethyl acetylaminomalonate to trans-β-nitroalkenes were carried out in a solid-liquid two-phase system in the presence of a d-glucose-based crown catalyst with up to 99% ee. 相似文献
5.
Different Michael addition reactions catalyzed by solid base K2O/γ-Al2O3 and KF/γ-Al2O3, MgO/γ-Al2O3 prepared by microwave irradiation method were reported in this paper. For the K2O/γ-Al2O3, not only good yield was attained but also made the reaction of Acetonitrile that usually is regarded as inactive carbonion and α, β-unsatumted compound to carry out. The yield of Michael reaction of Ethyl acetoacetate and Crotonaldehyde catalyzed by KF/γ-Al2O3, MgO/γ-Al2O3, MgO/NaY all could reach to 80% and the latter could reach to 90%. At the same time, the catalysts of different content(the ratio of load) of MgO were also applied in this reaction, and it was found that the best content of MgO was 20% ~ 25%。 相似文献
6.
Solvent-free Michael addition reaction of fluorene with chalcon 总被引:1,自引:0,他引:1
A series of novel Michael addition products of fluorene to chalcone were obtained in the presence of sodium hydroxide under solvent-free condition.The advantages of this procedure were mild reaction conditions,simple protocol,and high yields.The structures of the products were characterized by IR,~1H NMR,MS and X-ray diffraction.The crystal of the new compound 3 h is Triclinic,space group P-1 with a = 0.97352(6) nm,b = 1.08918(7) nm,c = 2.58418(16) nm,α= 80.1400(10)°,β= 79.5490(10)°,γ= 64.2440(10)°,V = 2... 相似文献
7.
Brian R. Linton Michael H. Reutershan Elizabeth A. Richardson Charles W. Ashley Scott J. Miller 《Tetrahedron letters》2007,48(11):1993-1997
Peptide-based catalysts have been developed that promote the asymmetric Michael addition of nitroalkanes. The most effective peptides contain a β-turn structural element as well as a basic histidine and an arylsulfonamide-protected arginine. Excellent yields with enantioselectivities of up to 74% ee have been observed. 相似文献
8.
Generosa Gómez 《Tetrahedron letters》2005,46(35):5819-5822
We describe an efficient new approach for the synthesis of highly substituted cyclohexane derivatives that is based on the oxidation of a furan ring with singlet oxygen followed by an intramolecular Michael addition of the resulting butenolide containing an acidic methine group. 相似文献
9.
Mingxiu Lv Mengwei Wang Kui Lu Lu Peng Yufen Zhao 《Phosphorus, sulfur, and silicon and the related elements》2018,193(3):149-154
A facile, rapid and cheap synthetic strategy towards a wide range of novel 2-aminoethylidene-1,1-bisphosphonate derivatives was developed through the Michael addition reaction of various aromatic amines, aromatic amides as well as nucleoside analogues with tetraethyl ethenylidene-1,1-bisphosphonate. All the newly obtained compounds were characterized by 1H, 31P, 13C NMR spectroscopy, IR and HR MS. 相似文献
10.
Hirokazu Iida Yusuke Akatsu Kazushi Mizukami Sho Natori Minako Matsukawa Kie Takahashi 《合成通讯》2016,46(7):581-585
The addition of phenols to acrylonitrile in the presence of aqueous benzyltrimethylammonium hydroxide or tetramethylammonium hydroxide under microwave irradiation yielded the corresponding Michael adducts. The obtained adducts were easily transformed to phenolic analogs of 4-phenylbutanoic acids via the hydrolysis of nitrile groups. 相似文献
11.
Marco L. Lolli Loretta Lazzarato Antonella Di Stilo Roberta Fruttero Alberto Gasco 《Journal of organometallic chemistry》2002,650(1-2):77-83
Tetraethyl ethenylidenebisphosphonate can undergo facile Michael type addition reaction with simple Grignard reagents to give alkyl, arylalkyl, aryl C-substituted methylene bisphosphonates. This addition easily occurs even if funtionalised Grignard reagents are used. 相似文献
12.
Jiong Jack Chen 《Tetrahedron letters》2003,44(17):3459-3462
Substituted anilines and vinyl sulfone undergo a facile double Michael addition to form substituted phenylthiomorpholine dioxide, catalyzed with AlCl3 or H3PO4. Scope and conditions were explored. 相似文献
13.
Apurba Chetia 《Tetrahedron letters》2004,45(12):2649-2651
A convenient one-pot synthesis of 1,7-dicarbonyl compounds has been accomplished by a three-component Michael addition reaction of nitromethane with two unsymmetric α,β-unsaturated carbonyl compounds in the presence of a base. 相似文献
14.
《Tetrahedron letters》2003,44(12):2463-2465
A Michael addition assisted by fluorapatite in heterogeneous media is described. Reaction between mercaptans and chalcone derivatives was studied at room temperature in methanol as solvent. By-products of usual undesirable reactions in Michael addition such as 1,2-addition, bis-addition and polymerisation are not observed. The yields obtained are good to excellent. 相似文献
15.
The asymmetric Michael addition of glycine imine esters to simple α,β-unsaturated ketones via PTC is investigated. It is found that by employing 1 mol % of a chiral quaternary ammonium salt, derived from α-methylnaphthylamine in conjunction with Cs2CO3, high enantioselectivities can be obtained in conjugate additions involving simple alkylvinylketones. 相似文献
16.
Susan Abraham 《Tetrahedron》2006,62(7):1474-1478
For the first time, asymmetric 1,4-addition of various malonates to enones has been carried out using tetrabutylammoniumtetrahydroborate (TBATB) in the presence of a chiral ligand. The Michael adducts were formed in reasonably good yields (61-67%) with moderate ee's at 0 °C. 11B NMR spectroscopic studies explain this unexpected reactivity through the predominant formation of an aminodiol modified borate complex in the presence of a hydride acceptor. 相似文献
17.
18.
采用紫外光谱动力学方法测定了抗肿瘤对映贝壳杉烯二萜冬凌草甲素和冬凌草乙素与谷胱苷肽迈克尔加成反应的级数、速率常数和平衡常数.结果表明,冬凌草甲素和冬凌草乙素与与谷胱苷肽迈克尔加成反应符合二级动力学方程,25℃下的速率常数分别为16.196 0L·(mol·s)-1和7.480 5L·(mol·s)-1,平衡常数分别为177.98L/mol和85.60L/mol.冬凌草甲素与谷胱苷肽迈克尔加成反应速率和反应程度均比冬凌草乙素的大得多,反应活性更好.对映贝壳杉烯二萜通过与机体发生迈克尔加成反应而产生抗肿瘤作用;因此,冬凌草甲素可能比冬凌草乙素具有更好的抗肿瘤活性. 相似文献
19.
Guai Li Wu Long Min Wu 《中国化学快报》2008,19(1):55-58
An efficient Michael addition of indoles to unsaturated enones, such as chalcones and β-nitrostyrenes, was achieved in the presence of a catalytic amount of nitrosonium tetrafluoroborate in ethyl ether. 2007 Long Min Wu. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved. 相似文献
20.
A recyclable and reusable (S) diphenylpyrrolinol silyl ether I organocatalyst bearing a n-C8F17 fluorous tag has been demonstrated for promoting the asymmetric Michael addition reactions of a wide range of aldehydes with both aryl and alkyl-substituted nitroolefins and excellent levels of enantio- and diastereoselectivities are achieved. The catalyst I can be conveniently recovered by fluorous solid-phase extraction and subsequently reused (up to eight cycles) without significant loss of its catalytic activity and stereoselectivity for the process. 相似文献