韩国梨花女子大学的Wonwoo Nam小组取得一项新突破，她们发现亚碘酰芳基-锰(III)卟啉在碳氢活化和氧原子转移反应中具有前所未有的反应活性。 该项研究成果发表在2020年11月13日出版的《美国化学会志》上。

研究小组报道了一种亚碘酰芳基-锰(III)卟啉，即[Mn^III(Porp)(^sArIO)]⁺，可以活化碳氢化合物的碳-氢键，这些碳氢化合物包括未活化的烷烃如环己烷等，且具有超高反应活性，具体表现为较低的动力学同位素效应、接近饱和的反应速率以及卟啉配体的电子效应对反应活性没有影响等特点。在氧原子转移反应（OAT）中，由[Mn^III(Porp)(^sArIO)]⁺催化的对位X取代的硫代苯甲醚的亚砜化反应在Hammett图上表现很反常，其反应速率表现出饱和行为，且卟啉配体的活性没有电子效应。

研究人员还对比了[Mn^III(Porp)(^sArIO)]⁺和Mn^IV(Porp)(O)复合物的反应性和机理。这一研究是第一个报道高活性亚碘酰芳基-锰(III)卟啉在碳氢活化和OAT反应中表现出前所未有的高反应性的案例。

附：英文原文

Title: Unprecedented Reactivities of Highly Reactive Manganese(III)–Iodosylarene Porphyrins in Oxidation Reactions

Author: Lina Zhang, Yong-Min Lee, Mian Guo, Shunichi Fukuzumi, Wonwoo Nam

Issue&Volume: November 13, 2020

Abstract: We report that Mn(III)-iodosylarene porphyrins, [MnIII(Porp)(sArIO)]+, are capable of activating the C–H bonds of hydrocarbons, including unactivated alkanes such as cyclohexane, with unprecedented reactivities, such as a low kinetic isotope effect, a saturation behavior of reaction rates, and no electronic effect of porphyrin ligands on the reactivities of [MnIII(Porp)(sArIO)]+. In oxygen atom transfer (OAT) reactions, the sulfoxidation of para-X-substituted thioanisoles by [MnIII(Porp)(sArIO)]+ affords a very unusual behavior in the Hammett plot with the saturation behavior of reaction rates and no electronic effect of porphyrin ligands on reactivities. The reactivities and mechanisms of [MnIII(Porp)(sArIO)]+ are then compared with those of the corresponding MnIV(Porp)(O) complex. The present study reports the first example of highly reactive Mn(III)–iodosylarene porphyrins with unprecedented reactivities in C–H bond activation and OAT reactions.

DOI: 10.1021/jacs.0c10159

Source: https://pubs.acs.org/doi/10.1021/jacs.0c10159