Metalloradical Catalysis for Selective Radical Reactions

通过这一奖项，美国国家科学基金会化学部的化学催化计划支持波士顿学院的彼得·张教授的研究。张教授正在开发新的金属络合物作为合成有机化合物的催化剂。大多数金属催化的过程依赖于化学家所说的“极性反应”，即反应涉及到一次两个电子的转移或共享。张教授发展了“金属催化”，即反应一次只涉及一个电子的转移或共享。张教授的新催化系统利用了这种自由基反应的独特特征。与通常需要稀有和昂贵的金属离子来催化双电子极性反应相比，单电子冶金反应是使用基于地球上丰富而廉价的过渡金属(如钴)的催化剂来进行的。因此，这项研究正在解决精细化工制造中的可持续性以及在生物、医学和材料方面的应用等重要问题。张教授还通过为K-12教师提供教育资源，激发K-12学生的科学兴趣，在普通大众中推广科学。除了对研究生和博士后研究人员进行科学培训外，张教授的实验室还为高中生和教师以及本科生提供第一手研究经验。张教授的研究重点是建立金属催化作为控制自由基反应的反应性和立体选择性的根本新方法。基于手性卟啉钴(II)络合物的金属配位体系正在开发中，以充分利用均裂自由基化学的潜力。这些新的催化自由基过程，既具有独特的机械特性，又具有操作吸引力，是构建有机化合物的宝贵合成工具，包括具有生物重要性的天然产物和具有药学意义的小分子。金属催化概念的提出，对有机合成产生了深远的影响，促进了以自由基化学为基础的新合成方法的发展。钴基金属催化剂的成功展示正促使人们发现基于开壳金属离子和手性配体的不同组合的新型金属催化剂体系，它们可以催化广泛的立体选择性自由基反应。虽然这项研究的重点是一般性的合成方法，但应用于合成靶点，包括第三类代谢性谷氨酸受体激动剂的靶点，可能会对大脑的正常神经功能产生影响。此外，张教授正在制作题为《生命的色彩》的公共教育材料，向当地K-12学校的学生展示。这些教育材料将通过网络以PowerPoint格式向公众提供。该奖项反映了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。

With this award, the Chemical Catalysis Program of the NSF Division of Chemistry is supporting the research of Professor Peter Zhang of Boston College. Professor Zhang is developing new metal complexes as catalysts for the synthesis of organic compounds. Most metal-catalyzed processes rely on what chemists call "polar reactivity" where reactions involve transfers or sharing of two electrons at a time. Professor Zhang develops "metalloradical catalysis" where reactions involve the transfer or sharing of only one electron at a time. Professor Zhang's new catalytic systems take advantage of the unique features of such radical reactions. In comparison with the typical need for rare and expensive metal ions for catalyzing two-electron polar reactions, the one-electron metalloradical reactions are carried out with catalysts based on earth-abundant and inexpensive transition metals such as cobalt. As such, this research is addressing important issues of sustainability in fine chemical manufacturing, and applications to biology, medicine, and materials. Professor Zhang is also promoting science among the general public by providing educational resources for K-12 teachers and stimulating scientific interests of K-12 students. In addition to scientific training for graduate students and postdoctoral researchers, Professor Zhang's laboratory provides first-hand research experiences to high school students and teachers as well as undergraduate students.Professor Zhang's research centers on establishing metalloradical catalysis as a fundamentally new approach for controlling reactivity and stereoselectivity of radical reactions. Metalloradical systems based on cobalt(II) complexes of chiral porphyrins are being developed to harness the full potential of homolytic radical chemistry. These new catalytic radical processes, which are both mechanistically distinctive and operationally attractive, are serving as valuable synthetic tools for the construction of organic compounds including biologically-important natural products and pharmaceutically-interesting small molecules. The concept of metalloradical catalysis, which aims at the full exploration of homolysis as a fundamental way for bond breaking and making, is having far-reaching impact on organic synthesis and is stimulating the development of new synthetic methods based on radical chemistry. The successful demonstration of cobalt-based metalloradical catalysis is prompting the identification of new metalloradical catalyst systems based on different combinations of open-shell metal ions and chiral ligands that can catalyze a broad range of stereoselective radical reactions. While this research focuses on generalizable synthetic methods, applications to synthetic targets, including targets that are group III metabotropic glutamate receptor agonists may have implications in the proper neuronal function of the brain. In addition, Professor Zhang is creating public educational materials entitled "The Colors of Life" presented to students in local K-12 schools. These educational materials are being made available for public access in PowerPoint format via the web.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.