Fundamental Reactions of Coordinated Ligands

配位配体的基本反应

• 批准号: 9727500
• 负责人: Joseph Templeton
• 金额: $ 38万
• 依托单位: University of North Carolina at Chapel Hill
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-02-15 至 2002-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9727500&HistoricalAwards=false
• 关键词: Fundamental; Reactions; Coordinated; Ligands

This award in the Inorganic, Bioinorganic, and Organometallic Chemistry program provides continued support for studies of fundamental reactions of coordinated ligands by Dr. Joseph L. Templeton, Department of Chemistry, University of North Carolina at Chapel Hill. Research will be carried out in three areas all involving the synthesis of organometallic complexes utilizing the tridentate hydridotris(3,5-dimethylpyrazolyl)borate ligand, Tp'. The strategy for each area is to explore fundamental reactivity patterns of coordinated substrate ligands. The first area extends the chemistry of chiral d4 complexes of tungsten previously shown to successfully control stereochemistry at ligand beta-sites. A cationic methylene carbene complex will be used for stoichiometric and catalytic reaction studies of substrate ligands. For example, catalytic aziridine formation occurs by reaction of ethyl diazoacetate with imine adducts. Single enantiomer studies will be pursued. The second and main area of the project involves the use of a new high oxidation state d2 tungsten oxo system which simultaneously accommodates both pi-acid and pi-base ligands. New d2 tungsten complexes should yield chiral organometallic derivatives that contain sigma or pi bound organic ligands. Preliminary results show interesting and different reactivities such as ligand coupling reactions (C-C bond formation) and proton addition at the oxo group converting W=O to W-OH, a rare example of an organometallic terminal hydroxo ligand. These reactions will be extended to seek catalytic transfer of nitrene and carbene ligands and to generate chiral d2 complexes suitable for promoting Lewis acid assisted organic transformations. The third area involves the preparation of chiral Tp' derivatives of Pt(IV) from known hydrido complexes in order to generate vacant sites for electrophilic activation of organic substrates. This work has potential for great impact because it may give insight into how C-H bond activation reactions work in electrophilic, late transition metal complexes. This project will increase our fundamental knowledge of transition metal mediated reactions of organic substrates. In addition, these and related compounds may have applications in promoting or catalyzing important organic transformations, including ones of interest to the chemical and pharmaceutical industries.

该奖项在无机，生物无机和有机化学 该计划为基本反应的研究提供了持续的支持 约瑟夫·L.坦普尔顿 化学，北卡罗来纳州查佩尔山大学。 研究将 在三个领域进行，都涉及有机金属的合成 三齿配合物 三（3，5-二甲基吡唑基）硼酸盐配体，Tp '。 战略 每个区域都将探索协调的基本反应模式， 底物配体 第一个领域扩展了手性d4 钨的络合物先前显示出成功地控制 在配体β-位点的立体化学。 一种阳离子亚甲基卡宾 络合物将用于化学计量和催化反应的研究， 底物配体 例如，催化氮丙啶形成通过以下发生： 重氮乙酸乙酯与亚胺加合物的反应。单一对映异构体 将继续进行研究。 该项目的第二个也是主要领域 涉及使用新的高氧化态D2钨氧代体系 其同时容纳π-酸和π-碱配体。 新 D2钨络合物应该产生手性有机金属衍生物， 含有σ或π键合的有机配体。 初步结果显示 有趣的和不同的反应性，如配体偶联反应 (C-C键形成）和在氧代基团处的质子加成，转化W=O 到W-OH，有机金属末端羟基配体的罕见实例。 这些反应将扩展到寻求氮烯的催化转移 和碳烯配体，并产生适合于 促进刘易斯酸辅助的有机转化。 第三区域 涉及由已知的Pt（IV）的手性Tp'衍生物的制备， 为了产生亲电空位， 有机基质的活化。 这项工作有很大的潜力 影响，因为它可以深入了解C-H键活化反应 在亲电的后过渡金属络合物中工作。 这个项目将增加我们对过渡金属的基础知识 有机底物的介导反应。 此外，这些与 化合物可用于促进或催化重要的 有机转化，包括化学和生物化学领域感兴趣的转化， 制药行业。