Organic Transformations with h2-Arene Complexes of Rhenium

在有机化学和大分子化学项目的支持下，弗吉尼亚大学化学系的W.Dean Harman教授正在研究使用Re的ETA-2芳烃配合物进行有机转化。通过将芳烃或多芳烃通过二氢配位选择性和可逆地结合到过渡金属上，它们对亲电性的反应性得到了增强。活性中间体(例如，芳基和烯丙基阳离子)是稳定的，有利于多环结构的组装。此外，金属配位还指导各种化学转化的立体化学，并保护配位以进行额外的转化。虽然芳烃的二次配位以前仅限于五胺基铯(II)配合物，但Harman教授正在开发一类新的基于Re(I)的脱芳构剂。芳香化合物(如苯、甲苯)是最容易获得的化合物类别之一，可用于精制成更复杂的分子结构。然而，它们的独特性质对可供其阐述的化学反应施加了一些限制。弗吉尼亚大学化学系的W.Dean Harman教授在有机和高分子化学项目的支持下，正在开发独特的金属试剂，使芳香化合物的反应性发生戏剧性的变化。通过他的研究，正在开发新的方法，使这些容易获得的起始材料可以方便地和选择性地转化为本身具有潜在意义的化合物，或者作为合成药物和其他精细化工产品的中间体。

With the support of the Organic and Macromolecular Chemistry Program, Professor W. Dean Harman, of the Department of Chemistry at the University of Virginia, is studying organic transformations using eta-2 arene complexes of rhenium. Through the selective and reversible binding of arenes or polyaromatic hydrocarbons through dihapto coordination to a transition metal, their reactivity toward electrophiles is enhanced. Reactive intermediates (e.g., arenium and allyl cations) are stabilized, facilitating the assembly of polycyclic structures. In addition, metal coordination directs the stereochemistry of various chemical transformations and protects the coordination site for additional transformations. While dihapto coordination of arenes has previously been limited to pentaammineosmium(II) complexes, Professor Harman is developing a new class of rhenium(I)-based dearomatization agents.Aromatic compounds (e.g., benzene, toluene) represent one of the most readily available classes of compounds for elaboration into more complex molecular structures. However, their unique properties place some limitations on the chemical reactions available for their elaboration. Professor W. Dean Harman, of the Department of Chemistry at the University of Virginia, with the support of the Organic and Macromolecular Chemistry Program, is developing unique metal-based reagents which allow for the dramatic alteration of the reactivity of aromatic compounds. Through his studies, new methods are being developed allowing the facile and selective conversion of these readily available starting materials to compounds of potential significance in their own right or as intermediates in the synthesis of pharmaceuticals and other fine chemical products.