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首页> 外文学位 >Part I: Use of quantitative structure selectivity relationships (QSSR) to predict the selectivity of new beta-aminoalcohols in the addition of diethyl zinc to benzaldehyde. Part II: Use of functionality mapping (FUNMAP) and database mining techniques (CAVEAT) in the development of a catalytic, enantioselective claisen rearrangement.
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Part I: Use of quantitative structure selectivity relationships (QSSR) to predict the selectivity of new beta-aminoalcohols in the addition of diethyl zinc to benzaldehyde. Part II: Use of functionality mapping (FUNMAP) and database mining techniques (CAVEAT) in the development of a catalytic, enantioselective claisen rearrangement.

机译：第一部分：使用定量结构选择性关系（QSSR）预测在将二乙基锌添加到苯甲醛中新的β-氨基醇的选择性。第二部分：在开发催化的，对映选择性的克莱森重排中，使用功能映射（FUNMAP）和数据库挖掘技术（CAVEAT）。

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摘要

Part I. The difference between diastereomeric transition states can be calculated via modern computational methods to explain the selectivity observed in certain reactions.* However, calculation of transition states is time consuming. To get around this, it was thought that Quantitative Structure Activity Relationships (QSAR), which are used in the pharmaceutical industry, could be used to correlate the ground states of catalysts with their selectivity in an asymmetric reaction. These Quantitative Structure Selectivity Relationships (QSSR) could then be used to predict the selectivity of novel catalysts.; As a proof of principle, the addition of Et2Zn to benzaldehyde catalyzed by beta-aminoalcohols was chosen for initial studies.* A valid QSSR model was found to correlate the ground state dimer structures of known beta-aminoalcohols with their selectivities in the above reaction. New ligands were then constructed and their selectivities in the Et2Zn addition to benzaldehyde were predicted. These ligands were then synthesized and tested to discover that there was a high degree of predictive power in this QSSR method. This research also led to the discovery of two new beta-aminoalcohols (shown below) that perform the Et2Zn addition to PhCHO with very high selectivity.*; Part II. The Claisen rearrangement was discovered by Ludwig von Claisen in 1912 and is shown below.* While the Claisen rearrangement has found numerous uses in organic synthesis, catalytic, enantioselective versions have remained elusive with only two examples to date.*; It was hypothesized that one could utilize catalytic amounts of a chiral hydrogen bond donor to perform an organocatalytic, enantioselective Claisen rearrangement. The proper ligand scaffold in the form of a bis-amidinium ion was identified via a functionality mapping (FUNMAP) and database mining (via the CAVEAT program) computational protocols developed in the Kozlowski labs. The bis-amidinium ion was then used in catalytic amounts to perform an enantioselective Claisen rearrangement of an allyl vinyl ether with a trifluoromethyl group in the C2-position.* Attempts were made to increase the enantioselectivity of the above reaction by changing temperature, concentration, solvent, and water content of the reaction, but these efforts were unsuccessful. However, the modest success achieved does warrant further research.; *Please refer to dissertation for diagrams.
机译：第一部分，非对映体过渡态之间的差异可以通过现代计算方法来计算，以解释在某些反应中观察到的选择性。*但是，过渡态的计算非常耗时。为了解决这个问题，人们认为，制药行业中使用的定量结构活性关系（QSAR）可用于使催化剂的基态与其在不对称反应中的选择性相关。这些定量结构选择性关系（QSSR）可用于预测新型催化剂的选择性。作为原理上的证明，选择了在β-氨基醇催化的苯甲醛中添加Et2Zn进行初步研究。*已找到有效的QSSR模型，将已知β-氨基醇的基态二聚体结构与其在上述反应中的选择性相关联。然后构建新的配体，并预测了它们在苯甲醛中Et2Zn加成中的选择性。然后合成并测试了这些配体，发现该QSSR方法具有很高的预测能力。这项研究还导致发现了两种新的β-氨基醇（如下所示），它们以非常高的选择性将Pht ECHO中的Et2Zn添加。第二部分克莱森重排由路德维希·冯·克莱森（Ludwig von Claisen）在1912年发现，如下所示。*克莱森重排在有机合成中发现了许多用途，但迄今为止，催化，对映选择性的形式仍然难以捉摸，*仅两个例子。假设可以利用催化量的手性氢键供体来进行有机催化的对映选择性克莱森重排。通过功能映射（FUNMAP）和在Kozlowski实验室中开发的数据库挖掘（通过CAVEAT程序）计算协议，确定了双-离子形式的合适配体支架。然后以催化量使用双-离子进行C2-位带有三氟甲基的烯丙基乙烯基醚的对映选择性克莱森重排。*尝试通过改变温度，浓度，溶剂和反应中的水含量，但这些努力均未成功。但是，取得的微不足道的成功值得进一步研究。 *请参考论文的图表。

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  • 作者

    Annamalai, Venkatachalam Raja.;

  • 作者单位

    University of Pennsylvania.;

  • 授予单位 University of Pennsylvania.;
  • 学科 Chemistry Organic.
  • 学位 Ph.D.
  • 年度 2006
  • 页码 397 p.
  • 总页数 397
  • 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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