Towards Absolute Asymmetric Synthesis

美国国家科学基金会化学部的化学合成项目通过该奖项支持威斯康星大学麦迪逊分校化学系的Tehshik Yoon教授的研究。尹教授对控制分子的形状很感兴趣。许多重要的有机分子，包括药物分子和基本生物分子，如氨基酸和糖，可以以左手或右手形式存在。这两种镜像形式以非常不同的方式与生物系统相互作用，因此在有机分子合成中控制手性至关重要。尹教授带领着一个由本科生和研究生组成的团队，研究光是否可以用来控制有机分子的手性。为了做到这一点，他们创造了一系列催化剂，这些催化剂可以吸收光，然后诱导分子转化，并对产物的形状有很好的控制。这项工作采用跨学科的方法，结合了化学科学的多个领域。此外，尹教授实验室的学生们正在制作新的播客，向初学自然科学的学生传播科学研究成果。这个播客的第一季已经通过各种免费播客平台被下载了2500多次。本项目的手性光催化剂为八面体铱配合物，其配体围绕金属排列，具有明确的螺旋手性。这类化合物构成了这些研究的一个有吸引力的起点：它们具有强大的和充分研究的光化学；对于一系列有机转化，它们是相当有效的光敏剂；它们很容易以立体化学纯形式合成。这些新设计的手性光敏剂是非常有效的不对称催化剂，多学科方法研究它们的反应揭示了丰富多样的机制。这些研究为不同群体的本科生和研究生提供了一个培训机会，这些学生对化学工业的科学领域有重要的当代兴趣。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

With this award, the Chemical Synthesis Program of the NSF Division of Chemistry is supporting research by Professor Tehshik Yoon of the University of Wisconsin–Madison’s Chemistry Department. Professor Yoon is interested in controlling the shape of molecules. Many important organic molecules, including drug molecules and elementary biomolecules such as amino acids and sugars can exist in either left- or right-handed forms. These two mirror-image forms interact with biological systems in very different ways, so it is critically important to control the handedness in the synthesis of organic molecules. Professor Yoon leads a team of undergraduate and graduate students to investigate if light can be used to control the handedness of organic molecules. To do so, they have created a family of catalysts that absorb light and then induce molecular transformations with excellent control over the shape of the resulting products. This work takes an interdisciplinary approach combining multiple areas of the chemical sciences. In addition, students in the Yoon laboratory working on this project are helping to disseminate scientific research to novice science students by producing a new podcast. The first season of this podcast has been downloaded over 2500 times through a variety of free podcasting platforms.The chiral photocatalysts in this project are octahedral iridium complexes whose ligands are arranged about the metal with well-defined helical chirality. This class of compounds constitutes an attractive starting point for these studies: they possess a robust and well-studied photochemistry; they are quite effective photosensitizers for a range of organic transformations; and they can easily be synthesized in stereochemically pure form. The newly designed chiral photosensitizers resulting from these studies are remarkably efficient asymmetric catalysts, and a multidisciplinary approach to studying their reactions reveals a rich variety of mechanisms. These studies offer a training opportunity for a diverse group of undergraduate and graduate students in scientific fields of significant contemporary interest to the chemical industries.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.