Study of the Michael addition of beta-cyclodextrin-thiol complexes to conjugated alkenes in water

An environmentally benign and highly efficient supramolecular Michael addition of thiols from the secondary side of beta-cyclodextrin to alpha,beta-unsaturated compounds at the primary side in water is described in quantitative yields; products of undesirable side reactions resulting from polymerization are not observed; the use of cyclodextrin precludes the use of either acid or base and the catalyst can be recovered and reused.     

CeO<Subscript>2</Subscript> nanoparticle-modified electrode as a novel electrochemical interface in the quantification of Zn<Superscript>2+ </Superscript>ions at trace level: application to real sample analysis

A simple strategy has been proposed to quantify Zn²⁺ ions using CeO₂ nanoparticle-modified glassy carbon electrode. The CeO₂ nanoparticles were prepared by sucrose-nitrate decomposition method, and it was characterized by X-ray diffraction (XRD), FT-IR, TEM, and surface area analyzer. The synthesized CeO₂ nanoparticles were used as modifier molecules as a thin film on glassy carbon electrode (GCE) in the trace level quantification of Zn²⁺ by using cyclic voltammetry (CV) and differential pulse anodic stripping voltammetry (DPASV) techniques. The fabricated sensor exhibited a good analytical response towards Zn²⁺ ions. The modified electrode showed a wide linearity in the concentration range 20–380 μg L^?1 with a limit of detection 0.36 μg L^?1. The proposed electrochemical sensor was successfully applied to trace level Zn²⁺ quantification from real sample matrices.     

FTIR光谱法研究天花粉蛋白的热去折叠过程

本文利用ＦＴＩＲ光谱技术和计算机辅助解析技术（二阶导数、去卷积和曲线拟合）研究了天花粉蛋白的热诱导去折叠过程。结果表明：在２５～８５℃温度范围内,天花粉蛋白的热去折叠是一个不可逆的分子间聚集的过程;二级结构随温度的变化暗示了折叠中间体的存在。     

Conversion of Epoxides to β‐Chlorohydrins with Thionyl Chloride and β‐Cyclodextrin in Water

Several epoxides are efficiently converted to the corresponding β‐chlorohydrins in impressive yields with thionyl chloride in the presence of β‐cyclodextrin using water as solvent at room temperature.     

Efficient Regioselective Ring Opening of Oxiranes with Thioacids in the Presence of β‐Cyclodextrin in Water

A mild and convenient synthesis of β‐hydroxy thioesters has been achieved by the regioselective ring opening of oxiranes using thioacetic acid and thiobenzoic acid in the presence of β‐cyclodextrin in water at room temperature. β‐Hydroxy thioesters are realized in high yields, and β‐cyclodextrin can also be recovered and reused.     

β-Cyclodextrin promoted allylation of aldehydes with allyltributyltin under supramolecular catalysis in water

A novel and highly efficient allylation of aldehydes using allyltributyltin has been developed in aqueous medium catalyzed by β-cyclodextrin in the presence of HCl without any metal catalysts to afford the corresponding homoallylic alcohols in good yields. The β-cyclodextrin can be recovered and reused for a number of runs without significant loss of activity.     

A new acylated isoflavone glucoside from Pterocarpus santalinus

Phytochemical investigation on the constituents of heartwood of Pterocarpus santalinus resulted in the isolation of a new acylated isoflavone glucoside. The structure of the new compound was elucidated on the basis of spectral studies as 4',5-dihydroxy-7-O-methyl isoflavone 3'-O-D-(3'-E-cinnamoyl)glucoside.     

β‐Cyclodextrin‐Supported,Completely Regioselective Ring Opening of Thiiranes with Thiophenol in Water

Thiolysis of thiiranes I with thiophenols II is performed efficiently in the presence of β‐cyclodextrin in water with high regioselectivity (Scheme, Table).     

Facile polystyrene/ZnO/Fe3O4 nanocomposites prepared via a hydrothermal approach for enhancement of MB dye degradation

Research on Chemical Intermediates - In this present work, polystyrene/ZnO and polystyrene/ZnO/Fe3O4 nanocomposites (NCs) were prepared by a hydrothermal synthesis method. The crystalline nature of...     

Synthesis of beta-hydroxysulfides from alkenes under supramolecular catalysis in the presence of beta-cyclodextrin in water

An environmentally benign and highly efficient procedure has been developed for the direct one-pot synthesis of beta-hydroxysulfides in good yields under neutral conditions from alkenes and thiophenols in the presence of aerial oxygen using beta-cyclodextrin in water. This protocol tolerates a wide variety of functional groups or substrates and does not require the use of either acid or base catalysts. beta-Cyclodextrin can be recovered and reused for a number of runs without any loss of activity.