Point-to-Axial Chirality Transfer: Enabling Stereochemical Determinations and Enantioselective Reactions

在这项由化学系化学结构、动力学和机制B计划资助的项目中，密歇根州立大学(MSU)化学系的Babak Borhan教授正在开发新的方法来识别有机分子的手性。手性，也被称为惯用手，是分子的一种重要性质。人类的手不是一模一样的，而是彼此的镜像(这两只手不是可以重叠的)。两个物体之间的关系，它们是彼此的镜像，具有手性中心，称为对映体。在生物学和医学中，对映体的例子不胜枚举。例如，在20世纪60年代末和70年代初使用的药物沙利度胺，导致了一些婴儿的胚胎错误发育，是对映体混合物的一个例子。其中一种对映体具有生物活性，可以作为一种抗恶心药物来治疗孕妇的晨吐。另一个对映体是致畸的，它干扰了正确的胚胎发育。这种药物是两种对映体的混合物，造成了悲剧。从这一经历中，科学家们了解到，识别分子手性的能力是至关重要的。Borhan小组正在开发新的方法来快速识别有机分子的手性，以确保沙利度胺等药物的安全性。博尔汉教授在密歇根州立大学组织和领导SEED计划活动。SEED项目是一个为期十周的暑期项目，部分资金来自美国化学协会和密歇根州立大学的各种组织，以支持来自经济困难家庭的高中生的研究。该项目的目标是为手性有机分子的绝对立体化学测定提供简单、快速、高效和明确的程序，其中许多手性有机分子是生物活性化合物或新分离的药理活性代谢物的合成中间体。该项目在很大程度上依赖于圆二色谱(CD)作为观察手性化合物和受体之间主客体相互作用的工具。感兴趣的官能团包括手性环氧化物、膦、膦氧化物、硼烷、烯烃、炔烃和烷基芳烃。此外，通过与结合的不对称客体分子相互作用而产生的超分子络合物的固有螺旋性将用于不对称催化剂。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

In this project, funded by the Chemical Structure, Dynamics, and Mechanisms-B Program of the Chemistry Division, Professor Babak Borhan of the Chemistry Department at Michigan State University (MSU) is developing new methods to identify the chirality of organic molecules. Chirality, also referred to as handedness, is an important property of molecules. Human hands are not identical, but mirror images of each other (the two hands are not superimposable). The relationship between two objects that are mirror images of each other, have a center of chirality, and are referred to as enantiomers. There are numerous examples of enantiomers in biology and medicine. For example, Thalidomide, a drug that was used in the late 1960s and early 1970s, led to the embryonic mis-development of a number of babies is an example of a mixture of enantiomers. One of the enantiomers was biologically active as an anti-nausea agent to treat morning sickness in pregnant women. The other enantiomer was teratogenic, which interfered with the correct embryonic development. The drug was given as a mixture of the two enantiomers, causing tragedy. From this experience, scientists have learned that the ability to identify the chirality of a molecule is of utmost importance. The Borhan group is developing new methods to rapidly identify the chirality of organic molecules to ensure the safety of drugs such as Thalidomide. Professor Borhan organizes and leads Project SEED activities at MSU. Project SEED is a ten-week summer program funded in part through the American Chemical Society and various organizations at MSU, to support the research of high school students from financially-disadvantaged families. The goals of the project are to provide simple, rapid, efficient, and non-ambiguous procedures for the absolute stereochemical determination of chiral organic molecules, many of which are synthetic intermediates of bioactive compounds or newly isolated pharmacologically-active metabolites. The project relies heavily on Circular Dichroism (CD) as the tool for observing the host-guest interactions between the chiral compounds and the receptors. The functionalities of interest include chiral epoxides, phosphines, phosphine oxides, boranes, alkenes, alkynes, and alkyl arenes. In addition, the endowed helicity of the supramolecular complexes, induced through interactions with the bound asymmetric guest molecules, will be used towards asymmetric catalysis.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.