Practical Strategies for Controlling Selectivity in Organic Reactions

描述（由申请人提供）：有一个基本的需求，发展化学转化是高度选择性和原子经济的。在一系列有机转化中，导向基团在控制区域化学和立体化学方面起着关键作用。然而，通常定向基团策略需要在有机底物中引入化学计量量的合成不需要的官能团（如膦）。该项目的长期目标是通过开发能够同时可逆地与金属催化剂和常见有机官能团（如醇、胺和羧酸）结合的配体来解决这一限制。通过使用配体作为支架将催化剂和底物暂时连接在一起，定向基团控制选择性的能力将与催化的实用性相结合。脚手架策略的价值在于，我们可以应用一个综合有用的官能团来结合配体，然后在期望的转化中调整配体的最佳性能。这一概念将应用于一系列底物的区域选择性、非映体选择性和对映选择性氢甲酰化。这一策略的成功应用将大大拓宽氢甲酰化（一种有效和实用的金属催化反应）可获得化合物的范围，并将为生物相关的杂环提供途径。一旦这个概念通过应用于催化氢甲酰化建立起来，我们将把这个想法应用于其他重要的过渡金属催化反应。

DESCRIPTION (provided by applicant): There is a fundamental need to develop chemical transformations that are highly selective and atom-economical. Directing groups have played a pivotal role in controlling regio- and stereochemistry in a range of organic transformations. However, often directing-group strategies require the introduction of stoichiometric quantities of synthetically undesirable functional groups (such as phosphines) into the organic substrates. The long-term goal of this program is to address this limitation by developing ligands that have the ability to simultaneously and reversibly bind to a metal catalyst and common organic functional groups (such as alcohols, amines, and carboxylic acids). By using a ligand as a scaffold to temporarily join the catalyst and substrate together, the power of directing groups to control selectivity will be coupled to the practicality of catalysis. The value of the scaffolding strategy is that we can apply a synthetically useful functional group to bind to the ligand, and then tailor the ligand for optimal performance in the desired transformation. This concept will be applied towards the regio-, diastereo-, and enantioselective hydroformylation of a range of substrates. Successful application of this strategy will significantly broaden the scope of compounds accessible from hydroformylation, an efficient and practical metal-catalyzed reaction, and will provide access to biologically relevant heterocycles. Once this concept is established through application to catalytic hydroformylation, we will apply this idea to other significant transition metal- catalyzed reactions. PUBLIC HEALTH RELEVANCE: In 2002, single enantiomer pharmaceuticals made up 40% of worldwide drug sales. Over the last twenty years the number of enantiopure drugs approved worldwide has steadily increased, while the percentage of achiral drugs decreased from 43 to 34% of all approved drugs. These trends have created a need for methods that efficiently and selectively make single stereoisomer products. The proposed studies directly address this need by developing a new strategy for controlling stereoselectivity in organic transformations.