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首页> 外文学位 >I. Studies of the mechanisms of solvolysis of multisubstituted sulfamoyl and benzoyl chlorides. II. Applications of a new N-heterocyclic carbene to the development of metal complexes and to cyanosilylation reactions .
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I. Studies of the mechanisms of solvolysis of multisubstituted sulfamoyl and benzoyl chlorides. II. Applications of a new N-heterocyclic carbene to the development of metal complexes and to cyanosilylation reactions .

机译：I.多取代的氨磺酰氯和苯甲酰氯的溶剂分解机理的研究。二。新型N杂环卡宾在金属配合物开发和氰基硅烷化反应中的应用。

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摘要

Nucleophilic substitution reactions with the reaction center being the carbonyl carbon of benzoyl chloride derivatives and with the reaction center being the sulfur of sulfamoyl chloride derivatives were studied under solvolytic conditions and the simple and extended Grunwald-Winstein equations were applied. The sensitivities of the rates of solvolysis towards changes in solvent nucleophilicity and solvent ionizing power are closely related to the amounts of bond forming and bond breaking at the transition state of the rate-determining step.;In the solvolyses of N,N-dimethylsulfamoyl chloride, it was found that the bond formation is an important factor in the rate-determining step. The 2,6-dichlorobenzoyl chloride and 2,4,6-trichlorobenzoyl chloride were found to follow a dissociative SN2 mechanism due to the steric hindrance from two ortho-chlorine substituents. For 2,4-dichlorobenzoyl chloride, two different mechanisms were found. These are the additionelimination mechanism in nucleophilic solvents and the dissociative SN2 mechanism in electrophilic solvents. The 3,5- and 3,4-dichlorobenzoyl chlorides were both found to follow an addition-elimination mechanism. Due to the decrease of steric hindrance on replacing the two chlorine atoms by the fluorine atoms at ortho-positions, 2,6-difluorobenzoyl chloride follows an addition-elimination mechanism in nucleophilic solvents and the dissociative SN2 mechanism only in the more electrophilic solvents. The 3,4,5-trimethoxybenzoyl chloride was found to follow the dissociative SN2 mechanism due to the strong electron-supplying resonance effect of the para-substituent being dominant over the weaker electron-withdrawing inductive effect of the three methoxy groups.;Based on the successful correlations of the specific rates of solvolysis of di- and tri-substituted benzoyl chloride derivatives, it is concluded that the application of the Grunwald-Winstein equations, especially the extended form, can give valuable mechanistic information concerning a solvolysis reaction at an acylcarbon.;N-Heterocyclic carbenes (NHCs) have been found to be extremely efficient ligands for the synthesis of metal complexes which are used in important organic reactions, such as olefin metathesis and the Heck reaction. We have exploited a very useful commercially available source for a carbene ligand, a triazole inner salt, given the common name nitron. We have succeeded in synthesizing ruthenium and palladium complexes incorporating this ligand and we have found that these complexes are highly active in ring-closing metathesis and Heck reactions.;Cyanosilylation is the most important method for preparing cyanohydrins, which are very useful building blocks in organic synthesis. The reactions of carbonyl compounds with trimethylsilyl cyanide (TMSCN) need a catalyst to activate the TMSCN. We have found the inexpensive and commercially available organocatalyst, lithium hexamethyldisilazide (LiHMDS) functions efficiently in this capacity and allows one to carry out the cyanosilylation of suitable aldehydes and ketones under mild conditions.
机译：在溶剂分解条件下，研究了反应中心为苯甲酰氯衍生物的羰基碳，反应中心为氨磺酰氯衍生物的硫的亲核取代反应，并应用了简单和扩展的Grunwald-Winstein方程。溶剂分解速率对溶剂亲核性和溶剂电离能力变化的敏感性与速率确定步骤过渡状态下键形成和键断裂的数量密切相关；在N，N-二甲基氨磺酰氯的溶剂化中，发现在速率确定步骤中键的形成是重要的因素。由于来自两个邻氯取代基的空间位阻，发现2,6-二氯苯甲酰氯和2,4,6-三氯苯甲酰氯遵循离解SN2机理。对于2,4-二氯苯甲酰氯，发现了两种不同的机理。这些是亲核溶剂中的加成消除机理和亲电溶剂中的离解性SN2机理。发现3，5-和3，4-二氯苯甲酰氯都遵循加成消除机理。由于减少了在邻位用氟原子取代两个氯原子的空间位阻，因此2,6-二氟苯甲酰氯在亲核溶剂中遵循加成消除机理，而仅在亲电子性溶剂中遵循离解SN2机理。发现3,4,5-三甲氧基苯甲酰氯遵循离解SN2机理，这是因为对位取代基的强电子供应共振效应优于三个甲氧基的较弱的吸电子诱导效应。成功地关联了二取代和三取代的苯甲酰氯衍生物的溶剂分解速率，得出的结论是，Grunwald-Winstein方程（尤其是扩展形式）的应用可以提供有关酰基碳溶剂分解反应的有价值的机理信息已经发现N-杂环卡宾（NHC）是用于金属络合物合成的极其有效的配体，所述金属络合物用于重要的有机反应，例如烯烃复分解和Heck反应。我们为卡宾配体（三唑内盐）开发了一种非常有用的市售来源，俗称硝酮。我们已经成功地合成了掺入该配体的钌和钯配合物，我们发现这些配合物在闭环易位和Heck反应中具有很高的活性。氰基硅烷化是制备氰醇的最重要方法，是有机合成中非常有用的组成部分合成。羰基化合物与三甲基甲硅烷基氰化物（TMSCN）的反应需要催化剂来激活TMSCN。我们已经发现便宜且可商购的有机催化剂六甲基二硅叠氮化锂（LiHMDS）以这种能力有效地起作用，并允许人们在温和的条件下进行合适的醛和酮的氰基硅烷化。

著录项

  • 作者

    Park, Kyoung-Ho.;

  • 作者单位

    Northern Illinois University.;

  • 授予单位 Northern Illinois University.;
  • 学科 Chemistry Organic.
  • 学位 Ph.D.
  • 年度 2009
  • 页码 196 p.
  • 总页数 196
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 有机化学;
  • 关键词

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