Mannich reaction in the synthesis of <Emphasis Type="Italic">N,S</Emphasis>-containing heterocycles. 2. Convenient one-pot synthesis of 3,5,7,11-tetraazatricyclo[7.3.1.0<Superscript>2,7</Superscript>]tridec-2-ene derivatives

The reactions of N-methylmorpholinium 6-amino-3,5-dicyano-1,4-dihydropyridine-2-thiolates with formaldehyde and primary aromatic amines produce 3,5,7,11-tetraazatricyclo[7.3.1.0^2,7]tridec-2-ene-1,9-dicarbonitrile derivatives. For Part 1, see Ref. 1. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2605–2607, November, 2005.     

Design of highly active heterogeneous palladium catalysts for the activation of aryl chlorides in Heck reactions

In situ generation of highly active palladium species by intermediate dissolution of Pd from solid supported catalysts has been demonstrated to be a very successful approach for the activation of aryl chlorides in Heck reactions. The new ‘heterogeneous’ Pd catalysts act as reservoir for molecular Pd species with unsaturated coordination sphere in solution. Crucial Pd leaching and re-deposition onto the support can be controlled by optimization of reaction conditions and by the properties of the catalysts. Pd is re-deposited onto the support at the end of the reaction. The catalysts, palladium supported on activated carbon, on various metal oxides or fluorides and Pd complexes in zeolites, are easy to prepare, though the preparation conditions are crucial. The catalysts convert all aryl bromides completely within minutes (TON 100,000). Aryl chlorides (even deactivated ones) are converted with high yields, within 2-6 h. The catalysts belong to the most active ones in Heck reactions at all (including best homogeneous systems) and fulfill all relevant requirements for practical applications in laboratory and industry.     

Synthesis of chiral N-protected 1,2-dihydro-quinoline-2-carbonitrile and 1,2-dihydro-isoquinoline-1-carbonitrile via an asymmetric Reissert reaction

Addition of cyanide ion to chiral N-acyl-quinolinium and N-acyl-isoquinolinium salts led selectively to 1,2-addition products. Removal of the chiral auxiliary affords the title compounds in pure enantiomeric form.     

Initiation Mechanism of Polymerization of Acryl－amide by Ceric Ion／2－Benzoyl Acetanilide System

ＩｎｉｔｉａｔｉｏｎＭｅｃｈａｎｉｓｍｏｆＰｏｌｙｍｅｒｉｚａｔｉｏｎｏｆＡｃｒｙｌ－ａｍｉｄｅｂｙＣｅｒｉｃＩｏｎ／２－ＢｅｎｚｏｙｌＡｃｅｔａｎｉｌｉｄｅＳｙｓｔｅｍＤＯＮＧＪｉａｎ－ｈｕａ，ＤＥＮＧＣｈａｏ，ＱＩＵＫｕｎ－ｙｕａｎａｎｄＦＥＮＧ...     

热可逆性共价交联热塑性弹性体的研究

本文以丙烯酸环戊二烯基已酯（ＣＰＤＥＡ）、烯丙基环成二烯（Ａ－ＣＰ）与丙烯酸乙酯（ＥＡ）进行乳液共聚，制得了含环成二烯侧基的共聚物．研究了工艺条件对转化率的影响，测定了共聚物的溶解性能和热转化行为．     

Optimizing control of simulated moving beds--linear isotherm

A new optimization based adaptive control strategy for simulated moving beds (SMBs) is proposed. A linearized reduced order model, which accounts for the periodic nature of the SMB process, is used for online optimization and control. The manipulated variables are the four inlet flow rates, the outputs are the raffinate and extract concentrations. Concentration measurements at the raffinate and extract outlets are used as the feedback information. The state estimate from the periodic Kalman filter is used for the prediction of the outlet concentrations over a chosen horizon. Predicted outlet concentrations are the basis for the calculation of the optimal input adjustments, which maximize the productivity and minimize the desorbent consumption subject to constraints on product purities. The realization of this concept is discussed and the implementation on a virtual eight column SMB platform is assessed, in the case of binary linear systems. For a whole series of typical plant disturbances it is shown that the proposed approach is effective in minimizing off-spec products and in achieving optimal SMB operation, also in the case where there are significant model uncertainties.     

A new strategy in enantioselective intramolecular hetero Diels-Alder reaction: catalytic double asymmetric induction during the tandem transetherification-intramolecular hetero Diels-Alder reaction of methyl (E)-4-methoxy-2-oxo-3-butenoate with rac-6-methyl-5-hepten-2-ol

An efficient catalytic double asymmetric induction during the tandem transetherification-intramolecular hetero Diels-Alder reaction has been developed. The enantioselective tandem reaction of methyl (E)-4-methoxy-2-oxo-3-butenoate with rac-6-methyl-5-hepten-2-ol has been achieved to provide methyl (2R,4aS,8aR)-3,4,4a,8a-tetrahydro-2,5,5-trimethyl-2H,5H-pyrano[4,3-b]-pyran-7-carboxylate in good yield with effective kinetic resolution (up to 95% selectivity), high diastereoselectivity (up to 92% de), and high enantioselectivity (up to 97% ee) in the presence of (S,S)-tert-Bu-bis(oxazoline)-Cu(SbF₆)₂ and 5 Å molecular sieves.     

新型Zhuo酚酮类糖苷化合物的合成

根据Zhuo酮的结构特点，对Zhuo酚酮类化合物与半乳糖的Kenigs-Knorr反应进 行了研究。探索出一种具有较高立体选择性的合成方法，从而制得四种具有β－构 型的单一端基异构体的Zhuo酚酮半乳糖苷新化合物。生成的新化合物不但保持了原 有的生理活性，而且降低了毒性、提高了药效，为人工合成Zhuo酚酮类增添新化合 物的同时，也扩展了此类化合物的应用领域。应用元素分析、核磁共振、红外光谱 表征了它们的结构。     

Potassium and sodium 2,6-di-tert-butylphenoxides and their properties

The crucial factor of the reaction of 2,6-di-tert-butylphenol with alkali hydroxides is temperature, depending on which two types of potassium or sodium 2,6-di-tert-butylphenoxides are formed. These types exhibit different catalytic activity in the alkylation of 2,6-di-tert-butylphenol with methyl acrylate. More active forms of 2,6-Bu^t ₂C₆H₃OK or 2,6-Bu^t ₂C₆H₃ONa are synthesized at temperatures higher than 160 °C and are predominantly the monomers, which dimerize on cooling. The data of ¹H NMR, electronic, and IR spectra for the corresponding forms of 2,6-Bu^t ₂C₆H₃OK and 2,6-Bu^t ₂C₆H₃ONa isolated in the individual state are in agreement with cyclohexadienone structure. In DMSO or DMF, the dimeric forms of 2,6-di-tert-butylphenoxides react with methyl acrylate to form methyl 3-(4-hydroxy-3,5-di-tert-butylphenyl)propionate in 64–92% yield. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2138–2143, December, 2006.