多羟乙基双核大环多胺La(III)配合物对双对硝基苯酚磷酸二酯和DNA 催化水解作用研究

合成了一类新型多羟乙基双核大环多胺La(III)配合物, 其结构经1H NMR, MS, 元素分析等表征. 通过紫外分光光谱法和琼脂糖凝胶电泳技术, 研究了双核大环多胺La(III)配合物催化双对硝基苯酚磷酸二酯的水解反应和对质粒DNA(pUC18)的催化水解作用. 结果表明: 双核大环多胺La(III)配合物可以有效催化双对硝基苯酚磷酸二酯水解和促进质粒DNA在生理条件下的水解裂解. 双对硝基苯酚磷酸二酯的水解速率提高了2.36×104倍. 讨论了配合物结构对水解反应的影响.     

[4+2] cycloaddition of intermediates generated from arynes and DMF

The trapping reaction of the transient intermediate ortho-quinone methides, generated by the insertion of arynes into a carbon–oxygen double bond of DMF, with dienophiles was investigated. The [4+2] cycloaddition products were obtained when the diesters of acetylenedicarboxylic acid were employed as dienophiles.     

A MILD METHOD FOR CONVERSION OF ALCOHOLS TO DIALKYL SULFITES BY USE OF Na2SO3/SOCl2

Alcohols are easily converted to their corresponding dialkyl sulfite under mild reaction conditions using Na₂SO₃/SOCl₂ in moderate to good isolated yields.     

Studies on BNPP Cleavage by Schiff Base Complexes Containing Benzoaza‐15‐Crown‐5 in DHAB Micellar Solution

Two novel benzoaza‐crown Schiff base cobalt (II) and manganese (III) complexes were synthesized and characterized. The hydrolysis of bis(4‐nitrophenyl) phosphate (BNPP) catalyzed by the two complexes was studied in buffer solution containing dihexadecyldimethylammonium bromide (DHAB) at 25°±0.1°C and different pH values. The kinetic mathematical model of BNPP hydrolysis was proposed, and the effects of different reaction conditions on BNPP hydrolysis were discussed. The results indicate that the two complexes (MnLCl and CoL) can efficiently accelerate the catalytic cleavage of BNPP in DHAB micellar solution. The pseudo‐first‐order rate constants (k _obsd) of BNPP hydrolysis catalyzed by the metallomicelles of MnLCl/DHAB and CoL/DHAB are 2.32×10⁷ times and 1.45×10⁷ times higher than that of the BNPP spontaneous hydrolysis, respectively. Possible reasons for the huge rate accelerations include the lower critical micelle concentration (cmc) of DHAB and formation of metallomicelles made of complexes and DHAB. Furthermore, the BNPP cleavage catalyzed only by the two complexes was investigated in buffer solution. It was found that the hydrolytic rates of BNPP catalyzed only by the two complexes were about 1% of those catalyzed by MnLCl/DHAB and CoL/DHAB systems at 25°C, pH=7.00, and [BNPP]=2.0×10^?4 mol · dm^?3.     

2，2，4－三甲基－1，3－戊二醇脂肪酸双酯中亚甲基质子的磁不等价性

在合成１３种２，２，４－三甲基－１，３－成二醇（ＴＭＰＤ）脂肪酸双酯的基础上，详细讨论了亚甲基中两个磁不等价质子的化学位移，偶合常数，谱线强度和磁不等价性与分子结构的关系。为了使ＴＭＰＤ脂肪酸双脂中各基团的相对取向能满足分子最稳定的条件，提出ＴＭＰＤ脂肪酸酯应按分子构型Ⅱ排列的结论。     

Practical selective monohydrolysis of bulky symmetric diesters

The highly efficient selective monohydrolysis reaction we previously reported has been applied to monohydrolysis of several bulkyl symmetric diesters, including diethyl esters, dipropyl esters, and dibutyl esters. A greater proportion of a polar aprotic co-solvent, DMSO, and aqueous KOH appear to help improve the reactivity of bulky diesters compared to the corresponding dimethyl esters. The procedure is mild and practical, yielding the corresponding half-esters in high yields under simple conditions.     

氯丙醇分子印迹自组装胶束的制备及其电化学传感性能

以双亲性无规聚合物和氯丙醇为组装基元,在选择性溶剂中制得氯丙醇分子印迹胶束,并将其电沉积在金电极表面得到分子印迹电化学传感器。采用Zeta电位及纳米粒度分析仪、透射电子显微镜表征了组装环境对形貌的影响。乳酸量、盐浓度和氯丙醇浓度对印迹胶束的组装行为有较大影响,当氯丙醇浓度为10~(-10)~10~(-4) mmol/L时制得的电化学传感器具有良好的线性响应。     

二元酸茄呢醇乙酰葡萄糖二酯的合成及其生物活性

二元酸茄呢醇单酯;体外活性;二元酸茄呢醇乙酰葡萄糖二酯的合成及其生物活性     

应用Atherton-Todd反应进行酪氨酸O-磷酰化

蛋白质磷酸化是细胞内调节酶功能的一种重要的翻译后修饰 .蛋白质内酪氨酸磷酰化是目前所知道的在细胞应答外界刺激时最主要的信号传导方式 [1] .文献 [2 ]报道的酪氨酸 O-磷酰化的方法是基于亚磷酰胺化学 ,包含亚磷酸化和氧化两步 .我们在 O-磷酰化多肽的合成研究中发现 ,应用 Atherton-Todd反应可以有效地进行酪氨酸 O-磷酰化 .Atherton- Todd反应是指二烷基亚磷酸酯在四氯化碳和有机碱 (如三乙胺 )存在下转变成二烷基磷酰氯 ,从而进行胺、亚胺及肟的磷酰化 .该法曾被有效地用于在弱碱性水溶液中合成 N - (二烷基磷酰 )氨基酸和小肽 […     

Synthesis of High Performance Thiophene–Aromatic Polyesters from Bio-Sourced Organic Acids and Polysaccharide-Derived Diol: Characterization and Degradability Studies

In this work, the feasibility of replacing petroleum-based poly(ethylene terephthalate) (PET) with fully bio-based copolyesters derived from dimethyl 2,5-thiophenedicarboxylate (DMTD), dimethyl 2,5-dimethoxyterephthalate (DMDMT), and polysaccharide-derived 1,6-hexanediol (HDO) was investigated. A systematic study of structure-property relationship revealed that the properties of these poly(thiophene–aromatic) copolyesters (PHS(20–90)) can be tailored by varying the ratio of diester monomers in the reaction, whereby an increase in DMTD content noticeably shortened the reaction time in the transesterification step due to its higher reactivity as compared with DMDMT. The copolyesters had weight-average molar masses (Mw) between 27,500 and 38,800 g/mol, and dispersity Đ of 2.0–2.5. The different polarity and stability of heterocyclic DMTD provided an efficient mean to tailor the crystallization ability of the copolyesters, which in turn affected the thermal and mechanical performance. The glass transition temperature (T_g) could be tuned from 70–100 °C, while the tensile strength was in a range of 23–80 MPa. The obtained results confirmed that the co-monomers were successfully inserted into the copolyester chains. As compared with commercial poly(ethylene terephthalate), the copolyesters displayed not only enhanced susceptibility to hydrolysis, but also appreciable biodegradability by lipases, with weight losses of up to 16% by weight after 28 weeks of incubation.