Sun Dongru, Chen Xiaolu, Gao Lanping, Zhao Yufen, Wang Yong
School of Material Science and Chemical Engineering, Institute of Drug Discovery Technology, Ningbo University, Ningbo, China.
Front Chem. 2020 Aug 20;8:744. doi: 10.3389/fchem.2020.00744. eCollection 2020.
Metal-iodosylarene complexes have been recently viewed as a second oxidant alongside of the well-known high-valent metal-oxo species. Extensive efforts have been exerted to unveil the structure-function relationship of various metal-iodosylarene complexes. In the present manuscript, density functional theoretical calculations were employed to investigate such relationship of a specific manganese-iodosylbenzene complex [Mn(TBDAP)(PhIO)(OH)] (). Our results fit the experimental observations and revealed new mechanistic findings. acts as a stepwise 1e+1e oxidant in sulfoxidation reactions. Surprisingly, C-H bond activation of 9,10-dihydroanthracene (DHA) by proceeds via a novel ionic hydride transfer/proton transfer (HT/PT) mechanism. As a comparison to , the electrophilicity of an iodosylbenzene monomer PhIO was investigated. PhIO performs concerted 2e-oxidations both in sulfoxidation and C-H activation. Hydroxylation of DHA by PhIO was found to proceed via a novel ionic and concerted proton-transfer/hydroxyl-rebound mechanism involving 2e-oxidation to form a transient carbonium species.
金属-亚碘酰芳烃配合物最近被视为一种仅次于著名的高价金属-氧物种的第二氧化剂。人们已经付出了巨大努力来揭示各种金属-亚碘酰芳烃配合物的结构-功能关系。在本手稿中，采用密度泛函理论计算来研究特定的锰-亚碘酰苯配合物[Mn(TBDAP)(PhIO)(OH)]（）的这种关系。我们的结果与实验观察结果相符，并揭示了新的机理发现。在亚砜氧化反应中作为逐步的1e+1e氧化剂。令人惊讶的是，通过一种新颖的离子氢化物转移/质子转移（HT/PT）机制进行9,10-二氢蒽（DHA）的C-H键活化。作为与的比较，研究了亚碘酰苯单体PhIO的亲电性。PhIO在亚砜氧化和C-H活化中均进行协同的2e-氧化。发现PhIO对DHA的羟基化通过一种新颖的离子且协同的质子转移/羟基回弹机制进行，该机制涉及2e-氧化以形成瞬态碳正离子物种。
