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Expanding Ligand-Metal Bifunctional Catalysis Scope

扩大配体-金属双功能催化范围

基本信息

批准号：
7274055
负责人：
TIMOTHY Bryan CLARK
金额：
$ 2.24万
依托单位：
UNIVERSITY OF WISCONSIN-MADISON
依托单位国家：
美国
项目类别：
财政年份：
2007
资助国家：
美国
起止时间：
2007-03-01 至 2007-08-31
项目状态：
已结题

项目摘要

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.

描述（由申请人提供）：Shvo 催化剂代表了一类具有配体-金属双功能催化作用的络合物，提供了独特的反应性流形。最近的报告对这些还原的催化循环提供了详细的机制见解，显示了电子耦合的酸性和氢氢的独特性质。目前，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输杂原子的类似钌络合物的开发。含有酸性羟基氢的钌结合正电性杂原子络合物的生成将提供具有前所未有的反应活性的钌催化剂。该提案重点关注 Shvo 催化剂的钌-硼基络合物，预计该络合物可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量。这种假设的反应性将在合成有机化学中具有广泛的应用。该项目的目标是开发硼烷和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其他杂原子。与有机合成中成熟的方法相结合，Shvo 催化剂的扩展包括钌-硼基络合物将有助于天然产物和药物靶标的制备。值得注意的是，β-杂原子取代的硼酸酯已用于合成几种天然产物。实现硼烷与高级合成中间体（例如复杂醛）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，其选择性是现有技术不可能实现的。该方法在合成中有许多应用。