Asymmetric Catalysis in Main Group Chemistry

主族化学中的不对称催化

基本信息

批准号：
9208778
负责人：
Scott Eric Denmark
金额：
$ 28.89万
依托单位：
UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN
依托单位国家：
美国
项目类别：
财政年份：
2010
资助国家：
美国
起止时间：
2010-03-22 至 2018-01-31
项目状态：
已结题

项目摘要

DESCRIPTION (provided by applicant): The carbon-carbon double bond is arguably the most important functional group in all of organic chemistry. Aside from its central position in defining structure, the ability to create two vicinal stereogenic carbon atoms by the introduction of two new bonds at the termini of a double bond has elevated it to this rarefied status. Countless reactions have been introduced to effect regio, diastereo and enantioselective functionalization of double bonds with good generality. However, only recently have organic chemists turned their attention to the enantiocontrolled introduction of elements in the main group such as sulfur, chlorine, bromine and iodine, in combination with the much more common elements carbon, nitrogen and oxygen. Although intriguing, these recent reports constitute an ad hoc application of known catalysts and concepts to the solution of creating new, catalytic enantioselective transformations. Our long-term goal is to construct the mechanistic/physical organic foundation for the development of generally applicable and highly selective alkene functionalization reactions. The primary objectives of this proposal are to: (1) apply the concept of Lewis base activation of Lewis acids developed in these laboratories, activate electrophilic species in Groups 16 and 17 in the Main Group, (2) learn the structure/reactivity correlations and the rules for achieving high catalytic activity (turnover frequencies and turnover numbers) for the target reactions, (3) design chiral Lewis bases that will impart high stereoselectivity and high chemical conversion for the introduction of new carbon and heteroatom substituted stereocenters, and (4) carry out detailed mechanistic (kinetic, spectroscopic, crystallographic, computational) investigations of the newly invented catalytic reactions described below. The first major effort will be the expansion of catalytic, enantioselective sulfenofunctionalization reactions to many substrate classes. Direct functionalization and cyclofunctionalization of alkenes bearing a tethered nucleophile (oxygen, nitrogen, carbon) is a powerful method for creating stereodefined chains, heterocycles, and carbocycles. Lewis basic catalysts of novel topology that can effect the stereoselective sulfenofunctionalization of E- and Z-alkenes will be designed and evaluated in many of these transformations. The second major effort, divided into two sub goals, is the development of catalytic, enantioselective halofunctionalization reactions. The development of catalysts for these extremely important transformations is guided by our demonstration that chloriranium ions are configurationally stable whereas bromiranium and iodiranium ions are not. Thus, the design criteria for these transformations diverge into two sub goals: (1) the design of catalysts that provide enantiotopic face differentiation for the delivery of a chlorenium ion, and (2) the design of catalysts that provide enantiotopic face differentiation for the delivery of a bromenium (iodenium) ion and stabilize the intermediate against racemization prior to capture.

描述（由申请人提供）：碳碳双键可以说是所有有机化学中最重要的功能群。除了定义的中心位置结构，通过在双键的末端引入两个新键来创建两个阴道立体源性碳原子的能力将其提升到了这种稀有状态。已经引入了无数的反应，以实现具有良好通用性的双键的区域，映射和对映选择性功能化。然而，直到最近才有有机化学家将注意力转移到主要群体中元素元素（例如硫，氯，溴和碘）中的引入，以及更常见的元素碳，氮和氧气。尽管很有趣，但这些最近的报告构成了已知的催化剂和概念的临时应用，用于创建新的催化对映选择性转换。我们的长期目标是为开发通常适用且高度选择性的烯烃功能化反应构建机械/物理有机基础。该提案的主要目的是：（1）应用这些实验室中开发的刘易斯酸的基础激活的概念，在主要组中激活第16和17组的亲电种物种，（2）结构/反应性相关性以及实现高催化活性的较高的反应率（3）设计（3）设计的规则（3）的规则（3）的规则（3）是chir chirist of strent of strent the te the（3）设计。以及用于引入新碳和杂原子取代的立体中心的高化学转化率，（4）对下面描述的新发明的催化反应进行了详细的机械（动力学，光谱，晶体学，晶体学，计算）研究。第一个重大努力是扩展对许多底物类别的催化，对映选择性磺化反应。载有链纤维蛋白（氧气，氮，碳）的烷烃的直接功能化和循环功能是一种强大的方法，可用于产生定型链，杂环和碳动物。在许多这些转换中，将设计和评估刘易斯的新拓扑基本催化剂，这些拓扑的基本催化剂可以影响E-和Z-Alkenes的立体选择性磺化功能。第二个主要的努力分为两个子目标，是催化，对映选择性呼吸功能反应的发展。这些极为重要的转化的催化剂的发展是由我们的证明指导的，即叶绿素离子在构型上是稳定的，而溴吡反型和碘丙烷离子却不是。因此，这些转换的设计标准分为两个子目标：（1）为映射的催化剂的设计，可以使氯离子的交付面对较差，以及（2）催化剂的设计，这些催化剂的设计为映射提供了对溴化（iodenium）离子（iodenium）离子和稳定性互动的催化剂的面部差异化，以相反的速度互动。