Lewis acid-catalyzed formation of Ugi four-component reaction product from Passerini three-component reaction system without an added amine

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.     

3-芳基-1-(吡啶-3-基)-2-(1H-1,2,4-三唑-1-基)-2-丙烯-1-醇的合成及生物活性研究

用硼氢化钠还原3-芳基-1-(吡啶-3-基)-2-(1H-1,2,4-三唑-1-基)丙烯酮, 合成了10个新型含吡啶基的三唑醇类化合物. 所有化合物均经核磁、元素分析确证. 生物活性测试结果表明, 部分化合物具有一定的杀菌活性及植物生长调节活性.     

Determination of dissociation energies of N-H bond in the 4-anilinodiphenylaminyl radical and O-H bond in the 2,5-dichloro-4-hydroxyphenoxyl radical from the equilibrium constants of chain reactions in quinoneimine-hydroquinone systems

The temperature dependences of the equilibrium constants of two chain reversible reactions in quinonediimine (quinonemonoimine)—2,5-dichlorohydroquinone systems in chlorobenzene were studied. The enthalpy of equilibrium of the reversible reaction of quinonediimine with 4-hydroxydiphenylamine was estimated from these data (ΔH = − 14.4±1.6 kJ mol⁻¹) and a more accurate value of the N-H bond dissociation energy in the 4-anilinodiphenylaminyl radical was determined (D _NH = 278.6±3.0 kJ mol⁻¹). A chain mechanism was proposed for the reaction between quinonediimine and 2,5-dichlorohydroquinone, and the chain length was estimated (ν = 300 units) at room temperature. Processing of published data on the rate constant of the reaction of styrylperoxy radicals with 2,5-dichlorohydroquinone in the framework of the intersecting parabolas method gave the O-H bond dissociation energy in 2,5-dichlorohydroquinone: D _OH = 362.4±0.9 kJ mol⁻¹. Taking into account these data, the O-H bond dissociation energy in the 2,5-dichlorosemiquinone radical was found: D _OH = 253.6±1.9 kJ mol⁻¹. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1661–1666, October, 2006.     

Accurate values for the nonrelativistic energies of the lowest singlet and triplet S-states of the4He-Isotop

Accurate lower and upper bounds for the nonrelativistic lowest energies¹ E ₀ and³ E ₀ of the singlet and triplet-system of the⁴He-Isotop are calculated with the linearized method of variance minimization. The same was done for¹ E ₁ the energy of the first excitedS-state 2¹ S. The results especially for¹ E ₀ and³ E ₀ in a.u. are −2.9033076997₅ ≤¹ E ₀ ≤ −2.9033076921₈ −2.1749324263₇ ≤³ E ₀ ≤ −2.1749324245₉ i.e. the values are determined with an absolute error smaller than 0.00167 cm⁻¹ for¹ E ₀ and 0.00039 cm⁻¹ for³ E ₀.     

A Facile Method of Synthesis of a Calix[4]arene Amide and the Crystal Structure of a Self-assembled Calix[4]arene Amide via van Der Waals Interaction

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.     

meso—四（对—羟基苯基）卟啉与脱氧核糖核酸的作用及其分析应用

报道了非离子型卟啉ｍｅｓｏ－四卟啉与脱氧核糖核酸的作用。在ＰＨ４．９－５．４范围内，ＤＮＡ能与聚合态的ＴＨＰ作用，产生不规则的电子吸收光谱。但如果体系中含有３０％（Ｖ／Ｖ）乙醇，ＤＮＡ与ＴＨＰＰ作用产生４５９．０ｎｍ和７００．０ｎｍ两个新峰。     

Subsolidus phase relations and crystal structure of compounds in the PrOx-CaO-CuO system

The subsolidus phase relations of the PrO_x-CaO-CuO pseudo-ternary system sintered at 950-1000°C have been investigated by X-ray powder diffraction. In this system, there exist one compound Ca₁₀Pr₄Cu₂₄O₄₁, one Ca₂Pr₂Cu₅O₁₀-based solid solution, seven three-phase regions and two two-phase regions. The crystal structures of Ca₁₀Pr₄Cu₂₄O₄₁ and Ca₂Pr₂Cu₅O₁₀-based solid solution have been determined. Compound Ca₁₀Pr₄Cu₂₄O₄₁ crystallizes in an orthorhombic cell with space group D_2h²⁰−Cccm, Z=4. Its lattice parameters are a=11.278(2) Å, b=12.448(3) Å and c=27.486(8) Å. The crystal structure of Ca₂Pr₂Cu₅O₁₀-based solid solution is an incommensurate phase based on the orthorhombic NaCuO₂ type subcell. The lattice parameters of the subcell of the Ca_2.4Pr_1.6Cu₅O₁₀ are a₀=2.8246(7) Å, b₀=6.3693(5) Å, c₀=10.679(1) Å, and those of the orthorhombic superstructure are with a=5a₀, b=b₀, c=5c₀. The Ca_2.4Pr_1.6Cu₅O₁₀ structure can also be determined by using a monoclinic supercell with space group C_2h⁵−P2₁/c, Z=4, a=5a₀, b=b₀, and β=104.79(1)° or 136.60(1)°, V=5a₀b₀c₀.     

C4/C5烃催化裂解制低碳烯烃的研究进展

从催化剂类型、裂解工艺、催化裂解的影响因素和裂解机理4个方面对国内外C4／C5烃催化裂解制低碳烯烃的研究进行了综述。催化裂解制低碳烯烃催化剂主要采用ZSM-5分子筛系列催化剂，在此基础上发展了酸改性或水热改性高硅ZSM系列分子筛及介孔MCM41分子筛。总结了国内外C4／C5烃的裂解工艺，认为影响催化裂解的主要因素是裂解原料、催化剂类型及工艺条件。目前，裂解机理主要是自由基与碳正离子机理相结合的机理。并简述了本课题组目前有关C4烷烃催化裂解的主要研究进展。