烯烃亲电加成反应的教学研究

烯烃的典型反应是亲电加成反应.大学有机化学教学目标要求学生掌握并能熟练应用烯烃亲电加成反应的区域选择性、立体选择性以及烯烃的反应活性解决实际问题.具体包括:(1)使用区域选择性预测加成主副产物;(2)使用立体选择性判断加成产物立体结构;(3)综合考虑电子效应,熟练比较各种烯烃的反应活性.由于烯烃亲电加成反应底物多、影响...     

An Efficient Ultrasound‐Assisted Synthesis of N‐Alkyl Derivatives of Carbazole,Indole, and Phenothiazine

Heterocyclic compounds bearing an acidic hydrogen atom attached to nitrogen such as carbazole, indole, and phenothiazine can be efficiently alkylated in DMSO or N,N‐DMF under ultrasonic irradiation in the presence of potassium hydroxide as a base. In almost all cases, a dramatic reduction of the reaction time results and a clear yield increase accompanied by an improved quality of the products occurs.     

一个与广义KKM定理等价的极小极大不等式

引进不用凸包定义的广义对角拟凹与拟凸概念,利用广义KKM定理,得到推广的Ky Fan极小极大不等式;并证明这个极小极大不等式、广义KKM定理与广义Ky Fan截口定理,三者是等价的。最后,利用不用凸包定义的广义对角锥拟凸概念,得到强向量均衡问题解的存在定理。     

离子液体在萃取技术中的应用

萃取是化学领域应用最广泛的一种单元操作。随着对离子液体研究的不断深入,离子液体以其低毒、低挥发以及可设计等特性,作为环境友好溶剂,在苯系有机物、农药残留、天然有机物、氨基酸、蛋白质、DNA以及金属离子等的萃取、检测技术方面的应用取得了一定的进展,如液液萃取、液相微量萃取、分散相液液微量萃取、固相微量萃取以及含水两相萃取等分离技术中不断有关于离子液体应用的报道,有的甚至取得了非常好的研究成果。本文就离子液体在萃取技术方面的应用,综述了近期国内外的研究进展,探讨了当前存在的问题及研究方向,展望了其应用前景。     

咪唑类离子液体催化的安息香缩合反应

α-羟基酮是一类重要的有机化合物,尤其是安息香,在化学、医药领域都有重要的应用.介绍了一种改进的安息香合成方法,在咪唑类离子液体氯化1-甲基-3-苄基咪唑盐的催化下,在温和的条件下,两分子醛发生缩合反应,以较高的产率得到目标化合物安息香.     

BEM for modal analysis of 3-D anisotropic structures

The boundary element method for the modal anlysis of free vibration for 3-D anisotropic structures using particular solutions has been developed. The complete polynomials of order two are used to construct the particular solutions for general anisotropic materials. The numerical results for 3-D free vibration analysis of an isotropic cantilever beam by the method presented is in good agreement with the results using the Ritz technique. For anisotropic materials, the numerical results calculated from the proposed method are in good agreement with the results from MSC.NASTRAN. Project supported by the National Natural Science Foundation of China (No. 19872011).     

基于萘酰亚胺-苯并咪唑鎓的荧光传感器对H2PO-4的高选择性识别

设计合成了基于萘酰亚胺-咪唑鎓的受体分子1和2,通过荧光发射光谱研究了受体分子1和2对阴离子F^-、Cl^-、Br^-、I^-、AcO^-、HSO^-₄、H₂PO^-₄、NO^-₃、ClO^-₄的识别性能。 研究发现,在受体分子1和2的乙腈溶液(5.0×10^-6 mol/L)中加入10倍化学计量的H₂PO^-₄时,受体分子1的荧光猝灭率高达98%,受体分子2的荧光猝灭率仅为24%。 表明具有多重识别位点的受体分子1在构型上与H₂PO^-₄更匹配,可作为H₂PO^-₄的荧光关闭型(turn-off)探针。 受体分子1与H₂PO^-₄的结合比为1∶1,结合常数为(1.25±0.11)×10⁵ L/mol,检出限为6.90×10^-6 mol/L。     

季膦离子液体促进的Morita-Baylis-Hillman反应

膦类离子液体,因其好的热稳定性以及在弱碱性介质中的惰性等优异特点,正在受到越来越多的关注.以廉价的三丁基膦和各种卤代烃为原料,制备了一系列季膦离子液体,然后以其与水组成的复合体系为反应介质,在催化剂1,4-二氮杂二环[2.2.2]辛烷(DABCO)作用下,进行了各种醛与丙烯腈、丙烯酸甲酯及丙烯酰胺的Morita-Baylis-Hillman反应研究.实验结果表明,在室温条件下,溴化乙基三丁基膦与水组成的复合溶剂体系,有效地促进了各种芳香醛及脂肪醛的Morita-Baylis-Hillman反应,不仅反应速度快,而且目标产物产率高.     

Efficient One-Step Synthesis of C 3-Symmetrical Benzenoid Compounds Mediated by SOCl2/EtOH

Abstract

An efficient one-step synthesis of branched functionalized benzenoid compounds from aryl methyl ketones mediated by SOCl₂/EtOH is described; some novel C ₃-symmetrical molecules were prepared with satisfactory yields. The method enjoys short reaction time and simple operation, and avoids use of organometallic reagents.     

An efficient ultrasonic-assisted synthesis of imidazolium and pyridinium salts based on the Zincke reaction

A mild and efficient method has been developed using ultrasound irradiation for the synthesis of imidazolium and pyridinium salts based on the Zincke reaction. Tertiary nitrogen nucleophiles such as pyridines and imidazoles can be alkylated with primary amine by simply using their ammonium form Zincke salts. In almost all cases, a clear yield increase results and a dramatic reduction of the reaction time accompanied by an improved quality of the products occurs.