Highly Regioselective Synthesis of Novel 4-O-Phosphorylated Paeonol Analogs

Abstract

4-O-phosphorylated paeonol derivatives were conveniently prepared by a facile method. Resacetophenone was prepared by the Friedel–Crafts acylation reaction of acetic acid with resorcinol. It was then phosphorylated regioselectively at the 4-O position using the Atherton–Todd reaction. An efficient, highly regioselective method to synthesize 4-O-phosphorylated paeonol derivatives is provided, and the approach has the merits of mild reaction conditions.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.     

Highly Sensitive and Fast‐Responsive Fluorescent Chemosensor for Palladium: Reversible Sensing and Visible Recovery

The well‐known rhodamine spiro‐lactam framework offers an ideal model for the development of fluorescence‐enhanced chemosensors through simple and convenient syntheses. Herein, we report a new tridentate PNO receptor, which was introduced into a rhodamine spiro‐lactam system to develop Pd²⁺‐chemosensor RPd4 , that displayed significantly improved sensing properties for palladium. Compound RPd4 shows a very fast response time (about 5 s), high sensitivity (5 nM ), and excellent specificity for Pd²⁺ ions over other PGE ions (Pt²⁺, Rh³⁺, and Ru³⁺). In addition, RPd4 displays quite different responses to different valence states of the Pd ions, that is, very fast response towards Pd²⁺ ions but slow response towards Pd⁰, which may provide us with a convenient method for the selective discrimination of Pd species in different valence states. According to proof‐of‐concept experiments, RPd4 has potential applications in Pd²⁺‐analysis in drug compounds, water, soil, and leaf samples. Owing to its good reversibility, RPd4 can also be used as a sensor material for the selective detection and visual recovery of trace Pd²⁺ ions in environmental samples.     

从三氟甲基化反应的近年进展看有机氟化学的发展趋势

由于含三氟甲基的化合物在医药、农药等领域得到广泛应用,发展向有机分子引入三氟甲基的方法成为当前的热点研究课题.分别总结了国外和我国学者近年(主要是2009～2011年)在三氟甲基化反应研究领域取得的研究成果.从近年三氟甲基化反应的研究进展,作者提出一些值得关注的有机氟化学发展方向.     

以2,2,5,5-四氟-2,5-二氢呋喃桥连的1,2-二噻吩乙烯类光致变色分子的合成

设计并合成了新型的以2,2,5,5-四氟-2,5-二氢呋喃桥连的1,2-二噻吩乙烯类光致变色分子1,从廉价易得的六氯丁二烯出发,经醇解、氯化、关环和氟化反应合成了关键中间体全氟2,5-二氢呋喃(2),并通过与化合物3'-溴-[2,2':5',2']三噻吩(3)的偶合反应得到含氟光致变色分子1.     

金属参与的N-酰基腙的偕二氟烯丙基化反应：高效合成偕二氟高烯丙基胺

金属铟参与醛衍生的N-酰基腙 1a-1q,4a-4g与3-溴-3,3-二氟丙烯 2 的反应,分别高效得到α, α-二氟高烯丙基肼 3a-3q,5a-5g。该反应条件温和,操作简便。硝基,酚羟基,苄氧基,α, β-不饱和醛的碳-碳双键等官能团对该反应具有良好的官能团兼容性。通过用锌粉代替铟粉, 酮衍生的N-酰基腙 6a-6d 也能发生偕二氟烯丙基化反应,以中等产率得到α, α-二氟高烯丙基肼 7a-7d。裂解肼3a的 N-N键顺利得到偕二氟高烯丙基胺 8,化合物 8 经丙烯酰化,随后进行RCM关环反应,可以方便的转化为偕二氟-γ-取代α, β-不饱和内酰胺 11。     

Characterization of the interaction between 8-bromoadenosine with human serum albumin and its analytical application

This study was designed to examine the interaction of 8-bromoadenosine with human serum albumin (HSA) by fluorescence spectroscopy in combination with molecular modeling under simulative physiological conditions. The results of fluorescence measurements indicate that 8-bromoadenosine has a strong ability to quench the intrinsic fluorescence of HSA through static quenching procedure. The binding constants (K) at different temperatures and thermodynamic parameters, enthalpy changes (ΔH) and entropy changes (ΔS) were calculated according to the fluorescence data. The results showed that the hydrophobic force played the major role in the binding of 8-bromoadenosine to HSA. The fluorescence experimental results were in agreement with the results obtained by molecular modeling study. The effects of some normal positive and negative ions on the binding constants were also discussed. Moreover, the synchronous fluorescence technique was used to characterize the interaction of 8-bromoadenosine to HSA and successfully applied to determine the total proteins in human serum, urine and saliva samples at room temperature under the optimum conditions with a wide linear range and satisfactory results.     

A redox-hydrothermal route to β-MnO2 hollow octahedra

Beta-Manganese dioxides' (β-MnO₂) hollow octahedra have been prepared by a synergetic redox reaction using cuprous chloride (CuCl) and hydrochloric acid (HCl) as reductants and potassium permanganate (KMnO₄) as oxidant through a hydrothermal route. During the process, the self-generated chlorine (Cl₂) gas bubbles and HCl's etching appear to be necessary for the formation of MnO₂ hollow structure. The catalytic efficiency of the prepared β-MnO₂ hollow octahedra was high which has been demonstrated by the catalytic oxidation of methylene blue (MB) dye in the presence of hydrogen peroxide (H₂O₂) under natural light.     

高师分析化学实验教学改革尝试

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