共查询到20条相似文献,搜索用时 0 毫秒
1.
Teresa M.V.D. Pinho e Melo Ana Lúcia Cardoso Jesús M. de los Santos Paulo E. Abreu Ana Matos Beja 《Tetrahedron》2008,64(35):8141-8148
A highly selective two-step approach to chiral β-amino esters via the hydride reductive amination of chiral allenes is reported. β-Enamino esters were obtained from the nucleophilic addition of amines to 2,3-allenoates bearing a chiral auxiliary. The reduction of the (1R)-(−)-10-phenylsulfonylisobornyl β-enamino esters gave the corresponding β-amino esters with S configuration whereas the reduction of the (1S)-(+)-10-phenylsulfonylisobornyl β-enamino esters led to β-amino esters with R configuration. The rationalization of the observed selectivity was supported by semi-empirical molecular orbital calculations (PM3). 相似文献
2.
Ryabova S. Yu. Alekseeva L. M. Lisitza E. A. Shashkov A. S. Chernyshev V. V. Tichomirova G. B. Goyzman M. S. Granik V. G. 《Russian Chemical Bulletin》2001,50(8):1449-1456
The possibility of transformation of 3-cyano-1-p-nitrophenyl--carbolin-2-one into 2-amino-3-cyano-1-p-nitrophenyl-1H-pyrido[3,2-b]indole derivatives and 2-imino-3-cyano-1-p-nitrophenyl-5H-pyrido[3,2-b]indole derivatives (-carbolines) is demonstrated. Methylation of 1-p-nitrophenyl-2-piperidino-1H--carboline followed by treatment with acetone in an alkaline medium yields 4-acetonyl-5-methyl-1,4-dihydro-5H-pyrido[3,2-b]indole derivative. The rearrangement of 2-arylimino-3-cyano-1-p-nitrophenyl-5H-pyrido[3,2-b]indoles into 2-(aryl)nitrophenylamino-3-cyano-5H-pyrido[3,2-b]indoles was accomplished on heating above the melting point or on treatment with potassium tert-butoxide. The structures of the resulting compounds were proved by 1H and 13C NMR spectroscopy and X-ray diffraction analysis. 相似文献
3.
József L. Margitfalvi Irina Borbáth Mihály Hegeds Sándor Gb?l?s Ferenc Lónyi 《Reaction Kinetics and Catalysis Letters》1999,68(1):133-143
General principles of modification of supported Pt catalysts with tin tetraalkyls are summarized and a new approach to prepare
supported Sn−Pt catalysts is described. The new approach leads to the formation of Multilayered Organometallic Complexes (MLOC)
anchored onto supported platinum. The formed MLOC can be decomposed either in reductive or oxidative atmosphere with the formation
of new type of supported Sn−Pt catalysts with high Sn/Pts ratios. The decomposition in a reductive atmosphere leads to the formation of alloy-type bimetallic phases, while the decomposition
in the presence of oxygen provides Lewis-acid type surface species anchored to supported platinum.
Dedicated to Professor Pál Tétényi on the occasion of his 70th birthday 相似文献
4.
《Tetrahedron》1988,44(17):5307-5318
Novel and effective routes to optically pure aromatic α-amino acids, α-methyl-α-amino acids and their derivatives including dipeptides are developed via homochiral β-lactams which are obtained through asymmetric [2+2] cycloadditions of ketenes to imines. 相似文献
5.
An efficient method for the asymmetric synthesis of β-trifluoromethylated β-amino ketones via addition of ketone-derivative enolates to trifluoromethylated sulfinylimine has been developed, with good chemical yields and excellent diastereoselectivities. This practical method was also proved to be suitable for large-scale preparation. 相似文献
6.
Jost U. Abronina P. I. Zinin A. I. Michalik D. Kragl U. Kondakov N. N. Chizov A. O. Torgov V. I. Kononov L. O. 《Russian Chemical Bulletin》2018,67(12):2297-2306
Russian Chemical Bulletin - New derivatives of serinol, 3-[4-(2-chloroethoxy)benzyloxy]-2-phthalimidopropan-1-ol and 3-[4-(2-azidoethoxy)phenoxy]-2-phthalimidopropan-1-ol, were synthesized and... 相似文献
7.
Roba Moumné 《Tetrahedron letters》2008,49(32):4704-4707
We describe here the aminomethylation of chiral silyl enol ether derivatives using iminium ion. The choice of judicious precursors with adequate protecting groups for the silylation/aminomethylation step was required to achieve the synthesis of β2-homotryptophane in few steps. The same methodology was used to prepare a β2-homolysine derivative. 相似文献
8.
《Tetrahedron letters》1987,28(37):4323-4326
A new red-ox reaction, leading to the respective keto derivatives from α-ketol and enone derivatives of cyclohexanone, is reported. 相似文献
9.
David A. Foley Patrick O'Leary N. Rachael Buckley Simon E. Lawrence Anita R. Maguire 《Tetrahedron》2013,69(6):1778-1794
The use of the intramolecular Buchner cyclisation of an α-diazoketone as an approach to the synthesis of daucane sesquiterpenes is described; in particular the synthesis of the cis-fused analogue of dihydro CAF-603. The key step in the synthesis is the intramolecular Buchner cyclisation, which provides the bicyclo[5.3.0]decane framework with the required stereochemistry at the quaternary centre generated in the cyclisation. A synthetic route enabling access to an asymmetric synthesis is also outlined. 相似文献
10.
Hosni Slimani Soufiane Touil 《Phosphorus, sulfur, and silicon and the related elements》2013,188(8):1655-1664
Abstract Two synthetic methods leading to β-iminophosphonates, phosphineoxides, and sulfides 2 are reported. The first method involves the reaction of imines with chlorophosphines and phosphites followed by oxidation or sulfurization. The second one utilizes the reaction of imines with diethylchlorophosphate and thiophosphate. The stereochemistry of the obtained products is discussed, and their structure is confirmed by NMR (1H, 31P, 13C) and IR spectroscopies, and by mass spectrometry. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file. GRAPHICAL ABSTRACT 相似文献
11.
Camphene or -pinene was treated with Cp2Zr(H)Cl (Cp = h5-C5H5) in THF to give organozirconium (IV) complexes, which were trapped with acetyl chloride or benzoyl chloride in the presence of CuI to afford ketones in yields of 63% to 74%. 相似文献
12.
Ildikó Loop 《Journal of fluorine chemistry》2010,131(3):389-395
Synthetic approach based on mediated addition of different trifluoromethylated building blocks to selected acyclic imines giving access to a variety of β-hydroxy-β-trifluoromethyl imines are elaborated. A reaction between fluorinated adducts and imines proceed easily giving the condensation products in good to excellent yields. β-Hydroxy-β-trifluoromethyl imines possessing trifluoromethyl group and exhibiting strong intramolecular hydrogen bonding are great precursors to different β-hydroxy-β-trifluoromethyl ketones and alcohols. 相似文献
13.
V. V. Belakhov A. V. Garabadzhiu I. V. Boikova I. A. Antonova 《Russian Journal of General Chemistry》2017,87(3):456-462
A method of synthesis of β-D-xylopyranoside thiophosphate derivatives was developed. Biological testing revealed a high insecticidal activity in the synthesized compounds. 相似文献
14.
Shipilov D. A. Kurochkina G. I. Levina I. I. Malenkovskaya M. A. Grachev M. K. 《Russian Journal of Organic Chemistry》2017,53(2):290-295
Russian Journal of Organic Chemistry - Reactions of 6-bromo- and 6-iodo-6-deoxy-β-cyclodextrin with organic amines of diverse nature afforded a series of monocationic derivatives with aminium... 相似文献
15.
A method for the synthesis of β-nitramino derivatives ofgem-dinitroalkanes by nitration of the products of condensation of sulfamic acid derivatives with the correspondinggem-dinitroalkanes was proposed. 相似文献
16.
17.
A highly enantioselective organocatalytic intermolecular conjugate addition of oximes to β-nitroacrylates has been developed. The highly functionalized adducts obtained are valuable precursors for asymmetric synthesis, as demonstrated by the synthesis of β(2,2)-amino acids and oxazolidin-2-ones. 相似文献
18.
M. L. Levit O. V. Nazarova I. V. Moiseyuk A. V. Dobrodumov E. V. Didenko E. F. Panarin 《Polymer Science Series B》2012,54(1-2):41-49
On the basis of hydrophilic copolymers of N-vinylamides??N-vinylpyrrolidone and N-methyl-N-vinylacetamide??that contain carboxylic or activated ester groups, new polymeric ??-cyclodextrin derivatives are synthesized via polymer-analogous transformations. Their solubility in water depends on the content of ??-cyclodextrin and the types of hydrophilic and reactive comonomers. 相似文献
19.
Alexander M. Jacobine Angela L.A. Puchlopek Charles K. Zercher Jon B. Briggs Jerry P. Jasinski Raymond J. Butcher 《Tetrahedron》2012,68(38):7799-7805
A zinc carbenoid-initiated chain extension reaction provides access to an organometallic intermediate, which can be used to capture activated imines. Deprotection of the nitrogen and reduction provides access to racemic derivatives of β-proline. The relative stereochemistry of the β-proline can be controlled through use of different activating groups on the imine nitrogen. 相似文献
20.
The reactions of α-trifluoromethylated α-arylacetates 1 with 3 equiv of hydrazine, methylhydrazine or benzylhydrazine in 1,4-dioxane at reflux for 24 h afforded the corresponding 5-fluoropyrazolin-3-one derivatives 3a-m in high yields. Similarly, treatment of 1 with 3 equiv of PhNLiNH2 in THF at −78 °C, followed by warming to room temperature, resulted in the formation of 3n-s in high yields. 相似文献