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排序方式: 共有80条查询结果,搜索用时 31 毫秒
1.
I. E. Karpeiskaya L. F. Godunova E. S. Levitina M. R. Lyubeznova E. I. Klabunovskii E. S. Shpiro G. N. Baeva E. D. Lubuzh L. B. Krentsel' A. D. Litmanovich N. A. Plate 《Russian Chemical Bulletin》1992,41(10):1858-1867
Pd complexes have been obtained from linear and cross-linked copolymers ofR,S-, R-, andS-1-(4-vinylphenyl)ethylamine (1) with styrene and divinylbenzene. Reduction of these compounds gave catalysts which were active in the reductive solvolysis of -acetaminocinnamic acid azlactone (2) and hydrogenation of the solvolysis products -acetamidocinnamic acid (ACA), its esters, and its 1-phenylethylamide. The catalysts showed no enantioselective properties in the reductive hydrolysis, but were more active than the catalyst obtained in the absence of the polymer (the monomeric analog). The use of polymeric catalysts has shown that, in reductive aminolysis, the chiral nucleophile plays the dominant part in determining the stereoselectivity of the reaction, rather than the chiral ligand of the catalytic complex. The polymer matrix stabilizes the low-valent state of the palladium in the complex. In the hydrogenation of ACA and its esters, the catalyst on the cross-linked polymer is much more active than its monomeric analog, but showed no enantioselectivity. Hydrogenation of acetamidocinnamic acidR-andS-1-phenylethylamides on a chiral Pd-polymer catalyst occurred with double asymmetric induction.Deceased.N. D. Zelinskii Institute of Organic Chemistry, Russian Academy of Sciences, 117913 Moscow. A. V. Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, 117912 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 10, pp. 2368–2380, October, 1992. 相似文献
2.
The reaction of 2,3-dihydro-2,3-benzo[b]furandione with the triphenylphosphazines of diazo compounds leads to substituted
2-methylenehydrazono-2,3-dihydro-3-benzo[b]furanones, which are hydrolyzed in an acidic medium to the substituted methylenehydrazides
of o-hydroxyphenylglyoxalic acid and react with amines to form the products of addition at the activated CH=N bond of the
side chain or 2-hydrazono-2,3-dihydro-3-benzo[b]furanone respectively.
__________
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 817–822, June, 2007. 相似文献
3.
R. A. Shagidullina E. P. Zhil'tsova L. A. Kudryavtseva 《Russian Chemical Bulletin》1998,47(9):1686-1689
The reaction ofn-hexylamine withO-alkylO-4-nitrophenyl chloromethylphosphonates in toluene solutions of poly(ethylene glycol)-600 monolaurate (PM) has been studied
by spectrophotometry. The reverse micelles of the nonionic surfactant increase more than tenfold the observed rate constant
of aminolysis. The catalytic activity of the surfactant is practically independent of the alkyl radical length of phosphonate.
An increase in the concentration of amine results in a decrease in the catalytic efficiency. The character of the dependence
of the rate constant on the concentration of PM is affected by the alkyl chain length of the substrate.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1735–1738, September, 1998. 相似文献
4.
S. N. Nikolaeva A. S. Zolotareva S. V. Ponomarev V. S. Petrosyan 《Russian Chemical Bulletin》1994,43(5):857-861
Dialkylamino- and alkoxytrialkylstannanes have been studied as N- and O-nucleophilic reagents in substitution reactions at the B-Br bond. The previously unknown bis(dialkylamino)- and dialkoxyboryl trialkylsilyl ketenes were synthesized. Some peculiarities of the reactivity of these compounds have been studied.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 911–915, May, 1994.This research was carried out in the framework of the Universities of Russia State Program. 相似文献
5.
V. N. Britsun A. N. Esipenko V. V. Pirozhenko M. O. Lozinskii 《Chemistry of Heterocyclic Compounds》2005,41(10):1334-1338
We have established that the products of aminolysis of 2-aryl-5-R-5,6-dihydro-7H-[1,2,4]triazolo-[5,1-b][1,3]thiazin-7-ones
in boiling ethanol are 3-R-3-(5-aryl-4H-1,2,4-triazol-3-ylsulfanyl)-propanamides, and at 180°C–210°C (depending on the structure
of the substituent R): 3-phenyl-4,5-dihydro-1H-1,2,4-triazoline-5-thione and 3-arylacrylamides or 3-(3-aryl-5-thioxo-4,5-dihydro-1H-1,2,4-triazol-1-yl)propanamides.
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Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1587–1592, October, 2005. 相似文献
6.
Yong Wu Hui-Biao Liu Yong-Jiang Liu Chun-Ying Duan Jun Hu Zheng Hu 《Journal of inclusion phenomena and macrocyclic chemistry》2000,36(4):473-478
A new facile method of synthesis of calix[4]arene amide via the aminolysis of the calix[4]arene esters was reported. One ethyl ester of the compound (2) was aminolysized byn-butylamine. The crystal structure of compound (1)shows that one ethyl ester of compound (1) enters into thecavity of another compound (1) forming a long chainhost-guest supramolecule. From the 2D NMR data, the compound(1) does not assemble in THF or CHCl3 solution. The CH- interaction and crystallization energy might be theimportant driving forces for forming the self-assembledcalix[4]arene. 相似文献
7.
G. H. Hu S. Lorek Y. Holl M. Lambla 《Journal of polymer science. Part A, Polymer chemistry》1992,30(4):635-641
The aminolysis of poly(styrene-co-methyl acrylate) (SMA) by octadecylamine in solution and in the melt has been reported in Part I. We now have studied the aminolysis of poly(ethylene-co-methyl acrylate) (EMA) with the same amine in the melt and compared the two sets of data in this paper. With EMA, the data confirmed and precised the catalytic mechanism proposed in Part I. The best tautomeric catalysts are the ones which form an eight-atom ring structure with the ester and amine groups. With EMA aminolysis is faster than with SMA because of the steric hindrance of phenyl groups in SMA. But EMA aminolysis remains a rather slow reaction. In a corotating twin-screw extruder the conversion was only around 4% at 220°C with a mean residence time of 150 s. It was also shown that the EMA/octadecylamine/catalyst system, like the SMA system, is homogeneous in the molten state at temperatures around 200°C. 相似文献
8.
Polyanionic cellulose carbamates were synthesized by rapid and efficient homogeneous aminolysis of cellulose carbonate half-esters in an ionic liquid/DMF medium. Cellulose bis-2,3-O-(3,5-dimethylphenyl carbamate), as a model compound, reacted with different chloroformates to cellulose carbonates. These intermediates were subjected to aminolysis, for which both the reactivity of different chloroformates towards C6-OH and the reactivity/suitability of the respective carbonate half-ester in the aminolysis were comprehensively studied. Phenyl chloroformate and 4-chlorophenyl chloroformate readily reacted with C6-OH of the model cellulose derivative, while 4-nitrophenyl chloroformate did not. The intermediate 4-chlorophenyl carbonate derivative with the highest DS (1.05) was then used to evaluate different aminolysis pathways, applying three different amines (propargyl amine, β-alanine, and taurine) as reactants. The latter two zwitterionic compounds are only sparingly soluble in pure DMF as the typical reaction medium for aminolysis; therefore, several alternative procedures were suggested, carefully evaluated, and critically compared. Solubility problems with β-alanine and taurine were overcome by the binary solvent system DMF/[EMIM]OAc (1:1, v/v), which was shown to be a promising medium for rapid and efficient homogeneous aminolysis and for the preparation of the corresponding cellulose carbamate derivatives or other compounds that are not accessible by conventional isocyanate chemistry. The zwitterionic cellulose carbamate derivatives presented in this work could be promising chiral cation exchangers for HPLC enantiomer separations. 相似文献
9.
Sergii Golota Ivan Sydorenko Roman Surma Olexandr Karpenko Andrzej Gzella 《合成通讯》2017,47(11):1071-1076
A multicomponent synthetic approach for 5-aryl/heterylidene-2-(2-hydroxyethylamino)- and 2-(3-hydroxypropylamino)-thiazol-4-ones starting from 2-thioxothiazolidin-4-one or 2-methylsulfanylthiazol-4-one was developed. The proposed method involves simultaneous aminolysis of 2-thioxo- or 2-methylsulfanyl groups and Knoevenagel condensation with (hetero)aromatic aldehydes using 2-aminoethanol or 3-aminopropan-1-ol as catalysts. Side-chain prototropic amino–imino tautomerism was observed for target 5-ylidene-2-alkylaminothiazol-4-ones. 相似文献
10.
In aqueous methylamine buffers of pH 10.21–11.25 nucleophilic cleavage of ionized (S–) phthalimide and general base-catalyzed cleavage of nonionized (SH) phthalimide is observed. 相似文献