The development of mild and efficient processes for the selective oxygenation of organic compounds by molecular oxygen (O2 ) is key for the synthesis of oxygenates. This paper discloses an atom-efficient synthesis protocol for the photo-oxygenation of 9,10-dihydroanthracene (DHA) by O2 to anthraquinone (AQ), which could achieve quantitative AQ yield (100 %) without any extra catalysts or additives under ambient temperature and pressure. A yield of 86.4 % AQ was obtained even in an air atmosphere. Furthermore, this protocol showed good compatibility for the photo-oxidation of several other compounds with similar structures to DHA. From a series of control experiments, free-radical quenching, and electron paramagnetic resonance spin-trapping results, the photo-oxygenation of DHA was probably initiated by its photoexcited state DHA*, and the latter could activate O2 to a superoxide anion radical (O2 .- ) through the transfer of its electron. Subsequently, this photo-oxidation was gradually dominated by the oxygenated product AQ as an active photocatalyst obtained from the oxidation of DHA by O2 .- , and was accelerated with the rapid accumulation of AQ. The present photo-oxidation protocol is a good example of selective oxygenation based on the photoexcited substrate self-activated O2 , which complies well with green chemistry ideals.

中文翻译：

---

在温和条件下，可见光触发O2将9,10-二氢蒽氧化为蒽醌。

发展温和而有效的通过分子氧（O2）选择性氧化有机化合物的方法是合成含氧化合物的关键。本文公开了一种原子有效的合成方案，用于将O2将9,10-二氢蒽（DHA）光氧化为蒽醌（AQ），在环境温度下无需任何额外的催化剂或添加剂即可实现定量AQ收率（100％）和压力。即使在空气气氛下，也可得到86.4％AQ的产率。此外，该协议显示出与具有DHA类似结构的其他几种化合物的光氧化的良好兼容性。通过一系列的控制实验，自由基猝灭和电子顺磁共振自旋俘获结果，DHA的光氧化可能是由其DHA *的光激发态引起的，后者可以通过其电子的转移将O2活化为超氧阴离子自由基（O2 .-）。随后，这种光氧化逐渐被含氧产物AQ作为活性光催化剂，该活性产物是由O 2--氧化DHA获得的活性光催化剂，并随着AQ的快速积累而加速。当前的光氧化方案是基于光激发的底物自活化O2的选择性氧化的一个很好的例子，它很好地符合绿色化学理想。