CARBOCATIONS AND BIO-RELATED REACTIONS

碳正离子和生物相关反应

• 批准号: 3272560
• 负责人: GEORGE A OLAH
• 金额: $ 27.43万
• 依托单位: UNIVERSITY OF SOUTHERN CALIFORNIA
• 依托单位国家: 美国
• 财政年份: 1978
• 资助国家: 美国
• 起止时间: 1978-07-01 至 1994-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3272560
• 关键词: X ray spectrometry; acylation; alkylation; boron; carbon; carbopolycyclic compound; carboxylation; chemical carcinogen; chemical models; chemical structure function; electron transport; hydrocarbons; nuclear magnetic resonance spectroscopy; stable isotope; terpenes; ultraviolet spectrometry

The principle aim of continued study is to extend our fundamental knowledge of carbocations, one of the most significant type of reactive organic intermediates and investigate representative in vitro cyclization, alkylation, and rearrangement reactions of biologically significant systems in which these ions play a significant role. New highly efficient non-oxidizing superacid systems based on boron tris- triflate and its conjugate acids will be developed for improved study of stable carbocations. Preliminary results indicate feasibility of these systems and significant advantages over previously used ones. Study of carbocations will be extended to new systems, including cage hydrocarbons. Methods to be applied to the investigation of carbocation intermediates will include NMR studies, including 13C-13C NMR spin coupling constants, solid state cross polarization-magic angle 13C NMR studies (to establish NMR parameters of the ions in the solid state and compare them with solution data of the same ions). X-ray structure determination of a series of isolate crystalling carbocation salts and their X-ray electron spectroscopic (ESCA) studies will be also carried out. With the proposed work detailed structural studies will be possible on the same ionic intermediates both in solution and in the solid state. As carbocations are the key intermediates both in varied alkylations, cyclizations, rearrangements, their knowledge is essential to a better understanding of these reactions, which can serve as models for enzymatic reactions. Solution studies alone are difficult, however, to relate to behavior at enzymatic sites. Solid state studies will allow a better understanding of relevant intermediates. Specific systems to be studied in regard to their potential bioalkylating ability will be aromatic hydrocarbons known for their carcinogenic activity. Study of derived arenium ion intermediates and related cations (dications) will be carried out under stable ion conditions. Further studies will center on rearrangement-cyclization reactions of biologically significant terpenes and on the interconversion of steroids under stable ion conditions. Studies will also be carried out on acylation, formylation and carboxylation systems emphasizing investigation of such fundamental ions as the formyl and isoformyl cations, carbonic acid, its remarkably stable protonated form and their reactions.

继续研究的主要目的是扩展我们的基本知识 碳碳，这是最重要的反应性有机物之一 中级和研究代表性的体外环化， 烷基化和生物学意义的重排反应 这些离子起着重要作用。 基于硼Tris-的新高效的非氧化超酸系统 将开发三叶酸盐及其共轭酸，以改善研究 稳定的碳化。 初步结果表明这些结果的可行性 与先前使用的系统相比，系统和显着优势。 研究 碳水化合物将扩展到包括笼烃在内的新系统。 适用于碳酸化中间体研究的方法 将包括NMR研究，包括13C-13C NMR自旋耦合常数， 固态交叉极化魔法角13C NMR研究（建立 离子的NMR参数在固态中，并将其与 同一离子的解决方案数据）。 X射线结构的确定 分离的结晶碳酸盐盐及其X射线电子 光谱学（ESCA）研究也将进行。 提议 在相同的离子上可以进行详细的结构研究 中间在溶液和固态中均以中间形式。 如碳芯 关键中间均以各种烷基化，环化， 重新排列，他们的知识对于更好地理解 这些反应可以用作酶促反应的模型。 但是，仅解决解决方案研究就很难与行为有关 酶位地点。 固态研究将使人们更好地理解 相关中间体。 有关其潜在的生物烷基的特定系统 能力将是芳族烃以其致癌而闻名 活动。 研究衍生的芳香离子中间体和相关阳离子的研究 （DICATIONS）将在稳定的离子条件下进行。 更远 研究将集中于生物学上的重排环化反应 明显的萜烯和稳定下类固醇的相互转换 离子条件。 研究还将在酰化，甲基化上进行 和羧化系统强调对这种基本的调查 离子为甲基和同胞阳离子，碳酸，其明显 稳定的质子化形式及其反应。