Low Oxidation State Complexes of Early Transition Metals with Aromatic Ligands

该奖项由无机，生物无机和有机化学 化学计划提供了一个项目的持续支持， 有机金属化学，其重点是活化 芳香烃的过渡金属铬。的 烃的活化在本发明中是非常重要的 化学和制药工业，因为碳氢化合物是 是合成大多数 有机化合物 研究的总体目标是探索和发展 早期高度还原的络合物的化学 具有芳族配体的过渡金属，特别是它们的 作为新序列中的中间体的潜力， 温和条件下的亲电芳烃取代反应。这些 实验建立在最近的观察基础上， 例如苄基氯或氢离子容易地加入到 苯三羰基铬的η-4-络合物，得到 环己二烯基络合物类似于通过以下制备的那些： 亲核加成到该铬化合物中。具体 该项目的目标包括：1）建立 苄基氧化加成的机理细节 氯化物与η-4-苯铬三羰基二价阴离子，2） 探索亲电官能团的范围， 会加入到活性芳烃中， η-4-芳烃铬三羰基二阴离子络合物，和3） 确定还原剂的反应范围和区域选择性 活化/亲电加成方法， 各种取代的三羰基铬络合物 芳烃。还原活化序列的可能性 与其它金属/配体模板配位的芳烃也将 审查，将还原活化的可行性， 配体。将使用萘酞减少 也可以作为制备早期的取代羰基金属化物的途径， 过渡金属杂环 配体。

This award from the Inorganic, Bioinorganic and Organometallic Chemistry Program provides continued support for a project in organometallic chemistry, the focus of which is the activation of aromatic hydrocarbons by the transition metal chromium. The activation of hydrocarbons is of great importance in the chemical and pharmaceutical industries, since hydrocarbons are the ultimate starting materials for the synthesis of most organic compounds. The overall objective of the research is to explore and develop the chemistry of highly reduced complexes of the early transition metals with aromatic ligands, particularly their potential as intermediates in a novel sequence for electrophilic arene substitution under mild conditions. These experiments build on the recent observation that electrophiles such as benzyl chloride or the hydrogen ion add readily to the eta-4-complex of benzenechromiumtricarbonyl, giving cyclohexadienyl complexes analogous to those prepared by nucleophilic addition to this chromium compound. Specific objectives of the project include 1) establishing the mechanistic details of the oxidative addition of benzyl chloride to the eta-4-benzenechromiumtricarbonyl dianion, 2) exploring the range of electrophilic functional groups which will add to the activated arenes in eta-4-arenechromiumtricarbonyl dianion complexes, and 3) determining the range and regioselectivity of reductive activation/electrophilic addition procedures with chromiumtricarbonyl complexes of a variety of substituted arenes. The possibility of reductive activation sequences with arenes coordinated to other metal/ligand templates will also be examined, as will the feasibliity of reductive activation of cyclopentadienyl ligands. Napthalenide reduction will be used also as a route to substituted carbonylmetalates of early transition metals with cyclopentadienyl and pi-heterocycle ligands.