一种稠合双环氮杂环丙烷衍生物便捷有效的合成路线

利用5-(R)-(L)-孟氧基-3-溴-2(5H)-呋喃酮和伯胺发生串联的Michael加成和分子内亲核取代反应,可以十分方便地得到光学纯的稠合双环氮杂环丙烷衍生物.这些氮杂环丙烷衍生物的结构均通过IR、1HNMR、13CNMR和EIMS的鉴定和表征.     

4-羟基香豆素类化合物与对醌的Michael加成反应

综述了不同条件下4-羟基香豆素类化合物与对醌的Michael加成反应及其反应机理．在丙酮-水中,4-羟基香豆素类化合物与1,4-苯醌反应生成2,3-二取代-1,4-苯醌,与1,4-萘醌反应生成2,3-二取代-1,4-蔡醌．在丙酮-水中,吡啶存在下,4-羟基香豆素类化合物与1,4-苯醌反应生成两性离子化合物;类似反应条件下,得到4-羟基喹啉酮两性离子化合物．4-羟基香豆素类化合物与2,3-二氯-5,6-二氰基对苯醌反应获得了新的螺环化合物．     

Asymmetric intramolecular oxa-Michael addition of activated <Emphasis Type=Italic>α,β</Emphasis>-unsaturated ketones by chiral <Emphasis Type=Italic>N</Emphasis>-triflyl phosphoramide

Asymmetric intramolecular oxa-Michael addition of activated α,β-unsaturated ketones by chiral N-triflyl phosphoramide was realized. The flavanone products can be synthesized with excellent yields (50%–95%) and up to 74% ee.     

查耳酮衍生物与丙二酸二酯的不对称迈克尔加成反应研究

查尔酮或带有查尔酮片段的衍生物具有抗炎症、抗细菌、除草等功效.以(R)-ALB为催化剂,叔丁醇钾作碱源,通过不对称迈克尔加成反应合成了一系列具有光学活性查耳酮片段的1,5-二羰基化合物,并且取得了良好的产率和极高的对映选择性.反应收率最高可达84%,反应的对映选择性最高可达98%.     

Relations between Karl Popper and Michael Polanyi

Karl Popper and Michael Polanyi grew up in central Europe and, having escaped from Nazism, went on to pursue academic careers in Britain where they wrote prolifically on science and politics. Popper and Polanyi corresponded with each other, and met for discussions in the late 1940s and early 50s, but they seldom referred to each other in their publications. This article examines their correspondence so as to produce a picture of their intellectual relations. The most important of the letters was one that Popper wrote in 1952, which we reproduce in its entirety, indicating his dissatisfaction with ideas that Polanyi had expressed in a paper of that year, ‘The Stability of Beliefs’. In this paper, Polanyi used the example of the framework of Zande witchcraft to shed analogical light on science and other systems of belief, arguing that ‘frameworks of belief’ equip their adherents with intellectual powers whose use reinforces commitment to the framework, inoculating adherents against criticism. Polanyi’s 1952 paper and his 1951 and 1952 Gifford Lectures (to which that paper is intimately tied) are the first articulation of Polanyi’s sharp rejection of the modern critical philosophical tradition that by implication included Popper’s philosophical ideas. The 1952 paper is also part of Polanyi’s constructive philosophical effort to set forth a fiduciary philosophy emphasizing commitment. Popper regarded Polanyi’s position as implying cognitive relativism and irrationalism, and from the time of Polanyi’s 1952 paper their personal relationship became strained. Discord between them became publicly manifest when Polanyi subtitled his book Personal Knowledge (1958), Towards a post-critical philosophy, and Popper lambasted the idea of a ‘post-critical’ philosophy in his Preface in The Logic of Scientific Discovery (1959).     

Michael定理在Fuzzy仿紧空间的推广

作者把一般拓扑中刻划仿紧性的Ｍｉｃｈａｅｌ定理推广到Ｆｕｚｚｙ空间。     

Density Functional Theory Study on the Addition Reactions of 4-methyl-benzaldoximes with Propene

The Michael addition reactions of Z and E 4-methyl-benzaldoximes with propene were investigated theoretically by DFT method at B3LYP/6-31G＊ level. The calculation results show that both addition reactions are concerted processes accompanied by the migration of hydrogen from the atom oxygen to carbon. Both products Z and E nitrones have dipolar charge distributions and activities. Z isomer is more favorable in the reaction due to the barrier is lower.     

(5R,4R)-5-(l-氧基)-4-膦酸二酯基-γ-丁内酯的合成

手性呋喃酮与亚磷酸三酯通过不对称Michael加成反应 ,得到了含磷官能团的新手性化合物 (5R ,4R) 5 (l 艹孟 氧基 ) 4 膦酸二酯基 γ丁内酯 .该反应具有条件温和、产率较高、光学纯度单一的特点 (d .e≥ 98% ) .通过元素分析 ,IR ,UV ,1HNMR ,13 CNMR ,MS ,[α]2 0D 波谱分析数据分析确定了该化合物的化学结构 .由于天然手性助剂薄荷醇价格低廉 ,以及 艹孟 氧基具有良好的立体选择控制性 ,因此 ,为合成含有磷官能团的新手性化合物提供了简便有效的途径 .     

An Analysis of Michael Long＇ s Interaction Hypothesis in Second Language Acquisition

The Interaction Hypothesis, which was first advanced by Michael Long, is considered as a further supplement or extension of the Input Hypothesis in the field of second language acquisition. This paper explains the main claims of Michael Long＇s Interaction Hypothesis, the three steps to study how input and interaction affect the acquisition of a second language, and the importance of the interactional modifications applied by both participants of the interaction. Emphasis is placed on the evaluation of the theory as well as its relation to second language teaching, with many researchers＇ findings and arguments discussed as supporting evidence. It aims to help the effective application of this theory in second language teaching.     

关于不对称酮的Michαel反应的剖析

本文利用反应机理、反应动力学和反应过程的位能图,导出了不对称酮的Michael反应主要发生在取代较多的位置上的理由。