Reactions of Trialkyl(2- or 4-Quinolyl)-Borates

Reactions of trialkyl(2-quinolyl)-borates and trialkyl (4-quinolyl)borates were investigated.     

On the Coloring Reaction of Dibromomethyl Carboxyazo with Iron

The reagents of unsymmetrical carboxyazo group as coloring agents are often used in the spectrophotometric determination of calcium, barium and aluminum, but rarely used in that of iron. Dibromomethyl carboxyazo is a new coloring agent, and can be used in the determination of barium. It is not found that the agent is used in that of other elements.     

Reaction of 2-(2-Azahetaryl)-4-chloro-3-oxobutyronitriles with Substituted Benzaldehyde Hydrazones. Unexpected Formation of 4-Arylideneamino-2-(1-R-benzimidazol-2-yl)-3-oxobutyronitriles

The reaction of 2-(2-azahetaryl)-3-oxo-4-chlorobutyronitriles with substituted benzaldehyde hydrazones gives 4-arylideneamino-2-(1-R-benzimidazol-2-yl)-3-oxobutyronitriles, the structures of which were proved using spectroscopic data, the results of elemental analysis, and through their chemical reactions. It was found that the reaction course depends on the basicity of the heterocyclic fragment in the starting nitrile. A likely mechanism for the process is proposed.     

手性催化剂的结构及其反应性能

以天然产物为前体对手性催化剂进行了分类，对每种手性催化剂列举了所催化的不对称反应及其对映选择性；并对催化剂的结构与反应性能的关系进行了初步的总结和分析。参考文献７０篇。     

Reaction of 4-nitro-1,2-phenylenedl4mine with 1-(4-R-phenyl)-3-(4-nitrophenyl)propenones

By the reaction of 4-nitro-1,2 phenylenediamine with 1-(p-R-phenyl)-3-(4-nitrophenyl)propenones, Michael adducts with a 1:2 composition have been obtained. A stagewise scheme is proposed for the formation of these compounds. The structure of one of the products has been established by means of x-ray structure analysis.Deceased     

Study on Color Reaction of 1-(4-Antipyrinylazo)-4-Amino -2-Naphthalic Acid with Copper(

在pH 6.0 HAc-NH     

1-(4-硝基苯基)-3-(3,5-二溴吡啶)三氮烯的合成及其与锌的显色反应研究

新合成了吡啶类三氮烯显色剂1-(4-硝基苯基)-3-(3,5-二溴吡啶)三氮烯(NPDBPDT),并研究了NPDBPDT与锌的显色反应。在Na2B4O7-NaOH缓冲溶液(pH 10.0)介质中,于表面活性剂Triton X-100存在下,锌与试剂生成1∶2络合物。该络合物在450 nm处有最大正吸收峰,以540 nm为参比波长,450 nm为测量波长进行双峰双波长测定,其表观摩尔吸光系数为2.17×105L.mol-1.cm-1,锌含量在0~12μg/25mL范围内符合比耳定律。     

Stereoselective Synthesis of Dialkyl 2-(Arylsulfonylamino)-3-(dialkoxyphosphoryl) Succinates by Reaction of Trialkyl(aryl) Phosphites,Dialkyl Acetylenedicarboxylates,and Arylsulfonamides

A three-component reaction of trialkyl(aryl) phosphites, dialkyl acetylenedicarboxylates, and arylsulfonamides is described as a simple and efficient route for the synthesis of dialkyl 2-(arylsulfonylamino)-3-(dialkoxyphosphoryl)-succinates in good yields.

Reaction of Methyl 5(6)-(4-Aminophenylthio)- 2-benzimidazolylcarbamate with Isocyanates

Methyl 5(6)-(4-aminophenylthio)-2-benzimidazolylcarbamate reacts with aliphatic and aromatic isocyanates to give mono- and disubstitution products. The former are formed by the reaction involving the aniline nitrogen and the latter, by the reaction involving both the aniline and benzimidazole nitrogens. Biological activity of the products was assessed.     

Reaction of 3-(4-Chlorofurazanyl-3-N(O)N-azoxy)-4-nitrofurazan with Weak Bases

When 3-(4-chlorofurazanyl-3-N(O)N-azoxy)-4-nitrofurazan reacts with weak bases and nucleophiles, we observe selective attack on the carbon atom bonded to the nitro group; we do not observe products formed by substitution of the chlorine.     

Structure of the Products of the Reaction of 4-Methylene-1,3-dioxolan-2-ones with Hydrazines

X-ray diffraction structural analysis was used to show the structure of one of the two products of the reaction of benzylhydrazine with 4,4-dimethyl-5-methylene-1,3-dioxolan-2-one and of the only product of the reaction of phenylhydrazine with the same dioxolanone. Both compounds are derivatives of 3-amino-4-hydroxyoxazolidin-2-one.     

Parallel Analysis of the Reaction Products from Combinatorial Catalyst Libraries

No Abstract     

Reaction of 2-allyloxy(thio)-4-methylquinolines with halogens

It was established that the halogenation of 2-allyloxy(thio)-4-methylquinolines leads to the formation of 3halogenomethyl-2, 3-dihydrooxazolo(thiazolo)[3, 2-a]quinolinium halides.Chelyabinsk State University, Chelyabinsk 454136. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1252–1254, September, 1996. Original article submitted July 7, 1996.     

Mechanism of the Reaction of Picryl Iodide with 4-[4-(Dimethylamino)styryl]pyridine

We have used semiempirical calculations (PM3, MNDOd) to show that the parabolic dependence of the rate constants (k_obs, s⁻¹) on the picryl iodide (PicI) concentration in the reaction of quaternization of 4-[4-(dimethylamino)styryl]pyridine (DASP) in acetonitrile is due to formation of an inactive σ_1,3 adduct from DASP and PicI. Formation of the σ_1,1 adduct is the rate-limiting step of the S_NAr substitution. __________ Translated from Teoreticheskaya i Eksperimental'naya Khimiya, Vol. 41, No. 4, pp. 242–246, July–August, 2005.     

Effect of Aging on the Nature of the Wichterle-Marek-Trekoval Catalyst

The effect of aging on the Wichterle-Marek-Trekoval (WMT) solid cationic catalyst for isobutene polymerization has been investigated. It was confirmed that this complex catalyst gives high molecular weight polyisobutenes at high rates at relatively high temperatures. Aging for various times and temperatures the Al(O-s-C₄H₉)₃/BF₃ component and the Al(O-s-C₄H₉)₃/BF₃/TiCl₄ final catalyst strongly depresses rates of polymerization but only slightly affects the molecular weights produced. Fastest rates and molecular weights are obtained with freshly prepared catalyst whose Ti/Al ratio is ～ 0.3 at about 30% conversions. Rates and polyisobutene molecular weights obtained by the present authors were higher than those reported by the Czechoslovakian workers. These results are discussed in terms of cationic polymerization mechanism, and an explanation for the reduced rates and molecular weights produced with aged WMT catalysts is proposed.