Zhao Liang, associate professor of Tsinghua University, reveals the key intermediates in the copper / oxygen catalytic system

Recently, Zhao Liang, associate professor of Chemistry Department of Tsinghua University, revealed the structure of key intermediate in Cu / O 2 catalytic system The research results were published in nature communications (DOI: 10.1038 / s41467-019-12889-w) under the title of "a merged coper (I / II) cluster isolated from Glaser coupling" Copper has rich redox properties, and its common oxidation states include Cu 0, Cu I, Cu II and Cu III Therefore, copper is not only common in the catalytic centers of many metalloenzymes, but also plays an important role in the catalysis of organic reactions In particular, the Cu / O 2-based catalytic system can not only activate small molecules in the multi copper oxidase (MCOs) and methane monooxygenase (pMMO), but also be widely used in many organic reactions as a green catalytic system with oxygen as oxidant However, previous mechanism studies mainly focused on the structure and reaction properties of copper-o active center (Cu-O species) and organic copper compounds (organocopper) However, as an important intermediate in the reaction process, copper-o-organic ternary complex is rarely separated Zhao Liang, Department of chemistry, Tsinghua University, has been committed to the combination of supramolecular chemistry and organometallic chemistry research methods to study the synthesis and reaction properties of organometallic clusters and polymetallic organic compounds In the previous research work, the research group has realized the controllable synthesis of a variety of organic metal clusters and carried out the research on their reaction activity It has found a new mode of action such as special bonding form and super conjugated aromaticity in the presence of multi metals The relevant research results have been published in several well-known academic journals Recently, the research group has successfully separated copper oxygen organic ternary complex intermediate (1) and more common binuclear Cu-O compound (2) in the same Glaser coupling reaction system by using macrocyclic template oriented strategy and macrocyclic ligands of different sizes The results show that although compounds 1 and 2 have similar coordination environment, they show different oxidation ability and reaction activity Compound 1 with copper oxygen organic ternary system has strong oxidation ability, and can react with a variety of organic compounds by single electron transfer (set) or hydrogen atom transfer (HAT) Compound 2 shows weak oxidation ability, so it has no hat activity This study revealed that the highly active cu-o-o-organic ternary complex formed in situ in the Cu / O 2 catalytic system is likely to be a real catalytic reaction intermediate, and its reaction activity is quite different from that of cu-o-species and organic copper compounds, which provides a new idea for the follow-up study of other Cu / O 2 organic catalytic systems and the reaction mechanism of copper-containing metalloenzymes The corresponding author of this paper is Zhao Liang, associate professor, and the first author is Zhang Siqi, Ph.D student, Department of chemistry, Tsinghua University The research was supported by Zhang Mingtian, associate professor of Chemistry Department of Tsinghua University, Xiao Hai, Jiang Shangda, Peking University, sun HaoLing, Beijing Normal University, and Tao Lizhi, Ph.D., University of California, Davis The research was supported by NSFC.