Zhang Dawei, Jamieson Kelsey, Guy Laure, Gao Guohua, Dutasta Jean-Pierre, Martinez Alexandre
Shanghai Key Laboratory of Green Chemistry and Chemical Processes , School of Chemistry and Molecular Engineering , East China Normal University , 3663 North Zhongshan Road , Shanghai , 200062 , P. R. China.
Laboratoire de Chimie , École Normale Supérieure de Lyon , CNRS , UCBL , 46 allée d'Italie , F-69364 Lyon , France.
Chem Sci. 2017 Jan 1;8(1):789-794. doi: 10.1039/c6sc03045a. Epub 2016 Sep 5.
Five sets of oxido-vanadium(V) complexes, which include both cages and open structures, were prepared and tested in the catalytic oxidation of sulfides. It was found that the hemicryptophane complexes, which are simultaneously comprised of cyclotriveratrylene (CTV), binaphthol and oxido-vanadium(V) moieties, are the most efficient supramolecular catalysts. The specific shape of the confined hydrophobic space above the metal center leads to a strong improvement in the yield, selectivity and rate of the reaction, compared to the other catalysts investigated herein. A remarkable turnover number (TON) of 10 000 was obtained, which can be attributed to both the high reactivity and stability of the catalyst. Similarly to enzymes, the kinetic analysis shows that the mechanism of oxidation with the supramolecular catalysts obeys the Michaelis-Menten model, in which initial rate saturation occurs upon an increase in substrate concentration. This enzyme-like behavior is also supported by the competitive inhibition and substrate size-selectivity observed, which underline the crucial role played by the cavity.
制备了五组氧化钒（V）配合物，包括笼状和开放结构，并在硫化物的催化氧化中进行了测试。结果发现，半穴状化合物配合物由环三藜芦烃（CTV）、联萘酚和氧化钒（V）部分同时组成，是最有效的超分子催化剂。与本文研究的其他催化剂相比，金属中心上方受限疏水空间的特定形状使反应的产率、选择性和速率得到显著提高。获得了高达10000的显著周转数（TON），这可归因于催化剂的高反应活性和稳定性。与酶类似，动力学分析表明，超分子催化剂的氧化机理符合米氏模型，即底物浓度增加时初始速率会达到饱和。观察到的竞争性抑制和底物尺寸选择性也支持了这种类似酶的行为，这突出了空腔所起的关键作用。
