RIKEN Center for Sustainable Resource Science, Wako, Saitama, 351-0198, Japan.
Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, 464-8601, Japan.
Sci Rep. 2021 Oct 21;11(1):20505. doi: 10.1038/s41598-021-99322-9.
We demonstrated microwave-assisted photooxidation of sulfoxides to the corresponding sulfones using ethynylbenzene as a photosensitizer. Efficiency of the photooxidation was higher under microwave irradiation than under conventional thermal heating conditions. Under the conditions, ethynylbenzene promoted the oxidation more efficiently than conventional photosensitizers benzophenone, anthracene, and rose bengal. Ethynylbenzene, whose T state is extremely resistant to intersystem crossing to the ground state, was suitable to this reaction because spectroscopic and related reported studies suggested that this non-thermal effect was caused by elongating lifetime of the T state by microwave. This is the first study in which ethynylbenzene is used as a photosensitizer in a microwave-assisted photoreaction.
我们使用苯乙炔作为光敏剂，展示了微波辅助亚砜的光氧化反应生成相应的砜。与传统的热加热条件相比，微波照射下的光氧化效率更高。在这些条件下，苯乙炔比传统的光敏剂二苯甲酮、蒽和玫瑰红孟加拉更有效地促进了氧化反应。苯乙炔的 T 态极不易发生系间窜跃到基态，因此适合这种反应，因为光谱和相关报道的研究表明，这种非热效应是由微波延长 T 态的寿命引起的。这是首次将苯乙炔用作微波辅助光反应中的光敏剂的研究。
