Photoinduced Asymmetric Catalysis with Chiral Metal Complexes

本课题组在光诱导不对称催化领域的研究工作中，利用手性金属双环取代铱铑配合物作为光活化的手性刘易斯酸催化剂。在许多情况下，催化剂/底物复合物充当光活性反应中间体。该提案将研究光激发的催化剂/底物复合物的反应性的新模式，并将它们与不对称催化相结合。第一个具体的目标将开发可见光诱导的催化剂和协调基板之间的内球电子转移。这种金属到配体的电荷转移产生还原的底物，其反应性（键形成或断裂化学）将在不对称催化的背景下被利用。第二个具体目标是从光激发的催化剂/底物复合物中发展氢原子转移反应，并将它们与不对称催化联合收割机结合起来。预计这项研究计划将提供新的见解设计策略，利用光激发态的催化剂/底物复合物，并最终导致新的可见光激活的催化不对称转化。

Our group has contributed to the development of photoinduced asymmetric catalysis by using chiral-at-metal bis-cyclometalated iridium and rhodium complexes as lightactivatable chiral Lewis acid catalysts. In many cases, catalyst/substrate complexes served as the photoactive reaction intermediates. This proposal will investigate new modes of reactivity of photoexcited catalyst/substrate complexes and interface them with asymmetric catalysis. The first specific aim will develop visible-light-induced inner-sphere electron transfer between the catalyst and coordinated substrates. This metal-to-ligand-charge-transfer generates reduced substrates whose reactivities (bond formation or fragmentation chemistry) will be exploited in the context of asymmetric catalysis. The second specific aim will develop hydrogen-atom-transfer reactions from photoexcited catalyst/substrate complexes and combine them with asymmetric catalysis. It is expected that this research plan will provide new insights into design strategies to exploit photoexcited states of catalyst/substrate complexes and will ultimately lead to novel visible-light-activated catalytic asymmetric transformations.