Expanding Ligand-Metal Bifunctional Catalysis Scope

描述（由申请人提供）：Shvo催化剂代表一类显示配体-金属双功能催化的络合物，提供独特的反应性多样性。最近的报告提供了详细的机理洞察这些还原的催化循环显示的独特性质的电子耦合的酸性和非质子化氢。目前，具有不饱和底物的配体-金属双功能催化仅限于氢化。该提案概述了用于传递杂原子的类似钌络合物的发展。含有酸性羟基氢的钌结合的正电性杂原子络合物的产生将提供具有前所未有的反应性的钌催化剂。该提案的重点是Shvo催化剂的钌-硼基复合物，预计该复合物将在极性不饱和底物的硼氢化反应中提供相当于硼基阴离子的作用。这种假定的反应性在合成有机化学中有着广泛的应用。本计画的目标是发展硼烷及乙硼烷与不饱和底物的不对称还原偶联反应。最终，该方法将扩展到包括额外的杂原子。结合有机合成中成熟的方法，将Shvo催化剂扩展到包括铼-硼基络合物将可用于制备天然产物和药物靶标。值得注意的是，杂原子取代的硼酸酯已经用于合成几种天然产物。实现硼烷到高级合成中间体（例如复合醛）的不对称还原偶联反应的能力将大大减少给定合成的步骤数。相关性：在过去的几十年里，由于能够将碳-主基键转化为天然产物和药物靶标中常见的官能团，将主基取代基掺入有机底物中受到越来越多的关注。该项目将允许将硼取代基引入复杂的有机分子中，其选择性是目前技术所不可能的。这种方法在合成中有许多应用。

DESCRIPTION (provided by applicant): The Shvo catalyst represents a class of complexes that display ligand-metal bifunctional catalysis, providing a unique reactivity manifold. Recent reports have provided detailed mechanistic insight into the catalytic cycle of these reductions displaying the unique nature of the electronically coupled acidic and hydridic hydrogens. Presently, ligand-metal bifunctional catalysis with unsaturated substrates is limited to hydrogenation. This proposal outlines the development of analogous ruthenium complexes for the delivery of heteroatoms. Generation of ruthenium bound electropositive heteroatom complexes containing the acidic hydroxy hydrogen would provide ruthenium catalysts that have unprecedented reactivity. This proposal focuses on ruthenium-boryl complexes of the Shvo catalyst which are expected to provide the equivalent of a boryl anion in the hydroboration of polar unsaturated substrates. This postulated reactivity would have widespread applications in synthetic organic chemistry. The goal of this project is to develop asymmetric reductive coupling reactions of boranes and diboranes with unsaturated substrates. Ultimately, this methodology would be expanded to include additional heteroatoms. In conjunction with well-established methods in organic synthesis, the expansion of the Shvo catalyst to include ruthenium-boryl complexes would be useful in the preparation of natural products and pharmaceutical targets. Notably, ?-heteroatom-substituted boronate esters have been used in the synthesis of several natural products. The ability to achieve asymmetric reductive coupling reactions of boranes to advanced synthetic intermediates (such as a complex aldehyde) would greatly reduce the number of steps of a given synthesis. Relevance: The incorporation of main group substituents into organic substrates have received increasing attention over the past several decades due to the ability to transform the carbon-main group bond into functional groups that are common in natural products and pharmaceutical targets. This project will allow for the introduction of boron substituents into complex organic molecules with selectivities that are not possible with the current technology. This method could have numerous applications in synthesis.