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首页> 外文学位 >I. Dynamic and thermodynamic investigation of thienyllithium based lithium/tellurium and lithium/iodine ate complexes. II. Dynamic and thermodynamic investigation of phenyllithium based lithium/iodine, lithium/antimony, and lithium/tin ate complexes. III. The investigation of sulfur stabilized organolithium reagent ion pair status and reactivity.
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I. Dynamic and thermodynamic investigation of thienyllithium based lithium/tellurium and lithium/iodine ate complexes. II. Dynamic and thermodynamic investigation of phenyllithium based lithium/iodine, lithium/antimony, and lithium/tin ate complexes. III. The investigation of sulfur stabilized organolithium reagent ion pair status and reactivity.

机译：I.基于噻吩锂的锂/碲和锂/碘酸盐配合物的动力学和热力学研究。二。基于苯基锂的锂/碘，锂/锑和锂/锡酸盐配合物的动态和热力学研究。三，硫稳定的有机锂试剂离子对状态和反应性的研究。

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摘要

The lithium/metalloid exchange reaction is an extremely mild and general procedure for the preparation of organolithium reagents. Ate complexes, first proposed by Wittig, are presumptive intermediates in lithium/metalloid exchange reactions which are widely used to prepare many kinds of synthetically valuable organolithium reagents. We investigated aryllithium ate complexes of Te, I, Sn and Sb via low temperature, heteronuclear NMR spectroscopy. DNMR analysis of the exchange of ArLi with Ar2Te, Ar3Sb, and ArI (Ar = diphenylphosphan-2-ylthienyl, phenyl, and m-ethylphenyl) have shown ate complexes to be key exchange intermediates. This provides the first examples of lithium/metalloid exchange systems that proceed exclusively through the ate complex intermediate.; The ability to form and utilize carbon nucleophiles is one the most important applications in organic chemistry. Stabilized organolithium carbanions such as dithioacetal and sulfonyl anions are particularly useful in organic syntheses. A key facet of the our group's research in recent years has been studying solution structure and mechanistic aspects of organolithium reagents in order to develop a better understanding of the relationship between structure and behavior. Solution studies of organolithium reagents have shown that they typically exist as a variety of aggregates, ion pairs, and chelates depending on the solvent mixture. The aggregation state and ion pair status—separated ion pair (SIP) or contact ion pair (CEP)—is known to have large effects on reactivities. Our work on the SN2 reactions of a series of lithium dithioacetal anions with a variety of alkyl halides in THF at −78°C has shown that the SEP is the only reactive species—the CIP does not react.
机译：锂/准金属交换反应是制备有机锂试剂的极其温和且通用的步骤。 Wittig首先提出的络合物是锂/准金属交换反应中的假定中间体，被广泛用于制备多种具有合成价值的有机锂试剂。我们通过低温异核NMR光谱研究了Te，I，Sn和Sb的芳基锂盐配合物。用DNMR分析ArLi与Ar 2 Te，Ar 3 Sb和ArI（Ar =二苯基膦-2-基噻吩基，苯基和 m -乙基苯基）已证明配合物是关键的交换中间体。这提供了锂/准金属交换系统的第一个例子，该系统仅通过复杂的中间体进行。形成和利用碳亲核试剂的能力是有机化学中最重要的应用之一。稳定的有机锂碳负离子，例如二硫缩醛和磺酰基阴离子，在有机合成中特别有用。近年来，我们小组研究的一个关键方面是研究有机锂试剂的溶液结构和机理方面，以便对结构与行为之间的关系有更好的了解。有机锂试剂的溶液研究表明，根据溶剂混合物的不同，它们通常以各种聚集体，离子对和螯合物的形式存在。众所周知，聚集状态和离子对状态（分离的离子对（SIP）或接触离子对（CEP））对反应活性有很大的影响。我们在-78°C下研究了一系列二硫代乙缩醛锂阴离子与各种烷基卤在THF中的S N 2反应的结果表明，SEP是唯一的反应性物质，CIP不会反应。

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  • 作者

    Bevan, Martin Joseph.;

  • 作者单位

    The University of Wisconsin - Madison.;

  • 授予单位 The University of Wisconsin - Madison.;
  • 学科 Chemistry Organic.
  • 学位 Ph.D.
  • 年度 2003
  • 页码 438 p.
  • 总页数 438
  • 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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