Malononitrile-involved Michael addition polymerization: An efficient and facile route for cyano-rich polyesters with programmable thermal and mechanical properties

An efficient, atom-economic, oxygen-tolerant, and water-tolerant strategy has been established to synthesize cyano-rich polyesters. Four kinds of organic bases, 1,1,3,3-tetramethylguanidine (TMG), 4-dimethylaminopyridine, triethylamine, and 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) were explored for accelerating Michael addition polymerization of malononitrile and 1,4-butandiol diacrylate. TMG can promote the polymerization efficiently under mild conditions to quantitatively afford polyester with high-molecular weight and moderate polydispersity. The comparison of the kinetic studies of TMG and TBD reveals that TMG shows better catalytic performance, while the catalysis of TBD brings about oligomers in spite of the higher efficiency at early age of the polymerization. Moreover, other diacrylate compounds could also be quantitatively polymerized to afford polyesters with high molecular weight. When dimethacrylate is chose as the monomer, the polymerization becomes sluggish. All the afforded polyesters display programmable thermal and mechanical properties that are closely related to their chemical structures.     

Caesium carbonate supported on hydroxyapatite‐encapsulated Ni0.5Zn0.5Fe2O4 nanocrystallites as a novel magnetically basic catalyst for the one‐pot synthesis of pyrazolo[1,2‐b]phthalazine‐5,10‐diones

A novel nanomagnetic basic catalyst of caesium carbonate supported on hydroxyapatite‐coated Ni_0.5Zn_0.5Fe₂O₄ magnetic nanoparticles (Ni_0.5Zn_0.5Fe₂O₄@HAP‐Cs₂CO₃) was prepared. This new catalyst was fully characterized using Fourier transform infrared spectroscopy, transmission and scanning electron microscopy, X‐ray diffraction and vibrating sample magnetometry techniques, and then the catalytic activity of this catalyst was investigated in the synthesis of 1H‐pyrazolo[1,2‐b]phthalazine‐5,10‐dione derivatives. Also, Ni_0.5Zn_0.5Fe₂O₄@HAP‐Cs₂CO₃ could be reused at least five times without significant loss of activity and could be recovered easily by applying an external magnet. Thus, the developed nanomagnetic catalyst is potentially useful for the green and economic production of organic compounds. Copyright © 2015 John Wiley & Sons, Ltd.     

正交试验法优化CS汽化吸附条件

通过正交试验设计,优化了影响西埃斯(CS)标准样品管制备的参数:汽化温度、采样流速、采样时间。结果表明,CS标准样品管的最佳吸附条件为汽化吸附温度:260℃,采样N2流速:330mL/min,采样时间:15min。在15~1500ng范围内,色谱峰面积与进样量有良好的线性关系,线性相关系数为0.9995,检出限为6.0ng。     

微波促进下N,N-二甲基甲酰胺中的Knoevenagel反应

在微波促进下，芳醛与丙二腈或氰基乙酸乙酯在DMF中进行Knoevenagel缩合反应，以77％～98％的产率生成相应E-式烯烃。     

Synthesis,alkylation, and molecular and crystal structure ofN-methylmorpholinium 6-amino-3,5-dicyano-1,4-dihydropyridine-4-spirocyclohexane-2-thiolate

The reaction of cyano(cyclohexylidene)thioacetamide with cyanothioacetamide or malononitrile andN-methylmorpholine yieldsN-methylmorpholinium 6-amino-3,5-dicyano-1,4-dihydropyridine-4-spirocyclohexane-2-thiolate. Its structure was established based on the results of alkylation and X-ray structural analysis.Deceased.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2535–2540, October, 1996.     

4-hydroxy-2-quinolones. 114. Synthesis and structure of 6-R-5-hydroxy-2,4-dioxo-2,3,4,6-tetrahydrobenzo-[<Emphasis Type="Italic">c</Emphasis>][2,7]naphthyridine-1-carbonitriles

Hydration of ethyl 1-R-4-dicyanomethyl-2-oxo-1,2-dihydroquinoline-3-carboxylate gives the corresponding substituted cyanoacetamides which are readily and quantitatively cyclized to 6-R-5-hydroxy-2,4-dioxo-2,3,4,6-tetrahydrobenzo[c][2,7]naphthyridine-1-carbonitriles in the presence of aqueous base. For Communication 113 see [1]. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 726–735, May, 2007.     

对-羟基苄叉丙二腈溶液在不同pH条件下吸收光谱的变化

在苄叉丙二腈衍生物系列中,N,N-二烷基氨基苄叉丙二腈及其类似化合物是研究和应用较多的一类。它们曾作为分子探针应用于高分子微环境特性和高分子聚合过程的研究。作为一种分子内的电荷转移络合物,它们在不同溶剂中的光谱行为也进行过研究,从而为进一步的开拓应用提供了重要依据。和前者相比,对-羟基苄叉丙二腈无论在基础研究或实际应用上都显得比较薄弱。正因如此,本工作合成了该化合物并对它进行了初步研     

微波辐射下2-氨基-7-甲基-4-芳基-5-氧代-4H,5H-吡喃并[4,3-b]吡喃-3-腈的一步合成

芳醛、丙二腈与6-甲基-4-羟基-2-吡喃酮在微波辐射下, 一步反应得到一系列2-氨基-7-甲基-4-芳基-5-氧代-4H,5H-吡喃并[4,3-b]吡喃-3-腈, 该反应时间短、产率较高、环境友好、后处理简单. 产物的结构经红外光谱、核磁共振谱和元素分析表征, 产物4g的结构经单晶X射线衍射进一步确证; 并对反应过程提出了可能的机理.     

Synthesis and crosslinking of cyano-substituted polyamides and polyimides prepared from 1-(2,2-dicyano-1-hydroxyviyl)-3,5-diaminobenzene,sodium salt

3,5-Dinitrobenzoyl chloide was condensed with malononitrile in the presence of sodium hydroxide under phase-transfer conditions to afford 1-(2,2-dicyano-1-hydroxyvinyl)-3,5-dinitrobenzene, sodium salt, which was catalytically hydrogenated to the corresponding diamine. The latter was used as starting material for the preparation of unsaturated cyanosubstituted polyamides and polyimides. The polymers were soluble in polar aprotic solvents, dilute sodium hydroxide, and certain strong inorganic and organic acids. Upon curing at 300°C for 65 h, crosslinked polymers were obtained that were stable up to 392–404°C in N₂ or air and afforded an anaerobic char yield of 60–71% at 800°C. Their glass transition temperatures as determined by thermal mechanical analysis (TMA) were 221–275°C. © 1995 John Wiley & Sons, Inc.     

某些新的含醛基和二氰基乙烯的偶氮染料的合成和可见光谱

红外染料可用于光学记录和光学数据储存,因此它是近年来发展的高技术领域之一。但是目前能应用的红外染料非常少,且绝大部份是菁染料。最近有人报道了醌型和偶氮型红外染料的合成。所谓红外染料是指λ_(man)在700nm以上的分子,含一个发色团体系往往是不够的。因此研究各类助色团和发色