Wanna Wondemagegn H, Janmanchi Damodar, Thiyagarajan Natarajan, Ramu Ravirala, Tsai Yi-Fang, Yu Steve S F
Institute of Chemistry, Academia Sinica, Taipei, Taiwan.
Sree Dattha Institute of Engineering and Science, Hyderabad, India.
Front Chem. 2020 Oct 26;8:589178. doi: 10.3389/fchem.2020.589178. eCollection 2020.
The process of selective oxy-functionalization of hydrocarbons using peroxide, O, HO, O, and transition metals can be carried out by the reactive oxygen species such as hydroxyl/hydroperoxyl radical and/or metal oxygenated species generated in the catalytic reaction. Thus, a variety of mechanisms have been proposed for the selective catalytic oxidation of various hydrocarbons including light alkanes, olefins, and simple aromatics by the biological metalloproteins and their biomimetics either in their homogeneous or heterogeneous platforms. Most studies involving these metalloproteins are Fe or Cu monooxygenases. The pathways carried out by these metalloenzymes in the oxidation of C-H bonds invoke either radical reaction mechanisms including Fenton's chemistry and hydrogen atom transfer followed by radical rebound reaction mechanism or electrophilic oxygenation/O-atom transfer by metal-oxygen species. In this review, we discuss the metal oxide nano-catalysts obtained from metal salts/molecular precursors (M = Cu, Fe, and V) that can easily form through the oxidation of substrates using HO in CHCN, and be facilely separated from the reaction mixtures as well as recycled for several times with comparable catalytic efficiency for the highly selective conversion from hydrocarbons including aromatics to oxygenates. The mechanistic insights revealed from the oxy-functionalization of simple aromatics mediated by the novel biomimetic metal oxide materials can pave the way toward developing facile, cost-effective, and highly efficient nano-catalysts for the selective partial oxidation of simple aromatics.
使用过氧化物、O、HO、O和过渡金属对碳氢化合物进行选择性氧官能化的过程可以通过催化反应中产生的活性氧物种（如羟基/氢过氧自由基和/或金属氧化物种）来实现。因此，人们提出了多种机制，用于生物金属蛋白及其仿生材料在均相或非均相平台上对包括轻质烷烃、烯烃和简单芳烃在内的各种碳氢化合物进行选择性催化氧化。涉及这些金属蛋白的大多数研究是铁或铜单加氧酶。这些金属酶在C-H键氧化过程中所采用的途径涉及自由基反应机制，包括芬顿化学和氢原子转移，随后是自由基反弹反应机制，或者是金属氧化物种的亲电氧合/O原子转移。在这篇综述中，我们讨论了从金属盐/分子前体（M = Cu、Fe和V）获得的金属氧化物纳米催化剂，这些催化剂可以通过在CHCN中使用HO氧化底物轻松形成，并且可以很容易地从反应混合物中分离出来，并以相当的催化效率循环使用几次，用于将包括芳烃在内的碳氢化合物高度选择性地转化为含氧化合物。由新型仿生金属氧化物材料介导的简单芳烃氧官能化所揭示的机理见解，可为开发用于简单芳烃选择性部分氧化的简便、经济高效且高效的纳米催化剂铺平道路。
