Oxidation of a Monomethylpalladium(II) Complex with O<sub>2</sub> in Water: Tuning Reaction Selectivity to Form Ethane, Methanol, or Methylhydroperoxide
作者:Anna V. Sberegaeva、Peter Y. Zavalij、Andrei N. Vedernikov
DOI:10.1021/jacs.5b12832
日期:2016.2.3
of ethane was found to be an unstable dimethyl Pd(IV) complex (dpms)Pd(IV)Me2(OH) (7), which could be generated from 5 and MeI. For shedding light on the role of MeOOH in the aerobic reaction, oxidation of 5 and 8 with a range of hydroperoxo compounds, including MeOOH, t-BuOOH, and H2O2, was carried out. The proposed mechanism of aerobic oxidation of 5 or 8 involves predominant direct reaction of excited
n-Pr4N[(dpms)Pd(II)Me(OH)] (5) 和 (dpms)Pd(II)Me(OH2) (8) (dpms = di(2-pyridyl)methanesulfonate) 的光化学有氧氧化研究了在 21°C 下 pH 值范围为 6-14 的水,发现以高产率的组合产生 MeOH、C2H6 和 MeOOH 的混合物以及水溶性 n-Pr4N[(dpms)Pd(II) (OH)2] (9). 通过改变反应的 pH 值和底物浓度,氧化反应可以导向选择性生产乙烷(高达 94% 的选择性)或甲醇(高达 54% 的选择性);MeOOH 的产率可以在 0-40% 的范围内变化。发现乙烷的来源是不稳定的二甲基 Pd(IV) 络合物 (dpms)Pd(IV)Me2(OH) (7),它可以由 5 和 MeI 生成。为了阐明 MeOOH 在有氧反应中的作用,5 和 8 被一系列氢过氧化物化合物(包括