南开大学朱守非团队报道了铁催化炔烃硅氢化反应中的自旋效应对氧化还原加速和区域选择性的影响。相关论文发表在2023年12月20日出版的《国家科学评论》。

铁催化剂是理想的过渡金属催化剂，因为铁盐具有丰富的地球资源、廉价的生物相容性。铁催化剂通常具有独特的开壳结构，在化学转化中容易发生自旋交叉，这在贵金属催化剂中是罕见的。不幸的是，目前对开壳结构和自旋交叉如何影响铁催化剂的反应性和选择性知之甚少，这使得铁催化剂的开发成为一个低效的试错程序。

该文通过实验和理论计算相结合，揭示了铁催化炔烃硅氢化反应是典型的自旋交叉催化。深入了解一组定义明确的开壳活性形式Fe（0）催化剂的电子结构表明，铁中心和1，10-  邻二氮杂菲配体之间的自旋离域有效地调节了铁中心的自旋和氧化态，分别满足氧化加成和还原消除的相反静电要求，并且自旋交叉对于该电子转移过程是必不可少的。三重态过渡态对于通过调节非键相互作用来实现高区域选择性是至关重要的。

这些发现为理解催化剂自旋状态对反应的影响提供了重要参考。这对铁催化剂和其他地球丰富金属催化剂的发展，特别是从配体发展的角度来看，具有启发性。

附：英文原文

Title: Spin effect on redox acceleration and regioselectivity in Fe-catalyzed alkyne hydrosilylation

Author: He, Peng, Hu, Meng-Yang, Li, Jin-Hong, Qiao, Tian-Zhang, Lu, Yi-Lin, Zhu, Shou-Fei

Issue&Volume: 2023-12-20

Abstract: Iron catalysts are ideal transition metal catalysts because of the Earth abundant, cheap, biocompatible features of the iron salts. Iron catalysts often have unique open-shell structures that easily undergo spin crossover in chemical transformations, a feature rarely found in noble metal catalysts. Unfortunately, little is known currently about how the open-shell structure and spin crossover affect the reactivity and selectivity of iron catalysts, which makes the development of iron catalysts a low efficient trial-and-error program. In this paper, a combination of experiments and theoretical calculations revealed that the iron-catalyzed hydrosilylation of alkynes is typical spin-crossover catalysis. Deep insight into the electronic structures of a set of well-defined open-shell active formal Fe(0) catalysts revealed that the spin-delocalization between the iron center and the 1,10-phenanthroline ligand effectively regulates the iron center's spin and oxidation state to meet the opposite electrostatic requirements of oxidative addition and reductive elimination, respectively, and the spin crossover is essential for this electron transfer process. The triplet transition state was essential for achieving high regioselectivity through tuning the nonbonding interactions. These findings provide an important reference for understanding the effect of catalyst spin state on reaction. It is inspiring for the development of iron catalysts and other Earth-abundant metal catalysts, especially from the point of view of ligand development.

DOI: 10.1093/nsr/nwad324

Source: https://dx.doi.org/10.1093/nsr/nwad324