荒川, 幸弘 Tokushima University 徳島大学 教育研究者総覧 KAKEN研究者をさがす
Mihara, Tomohiro Tokushima University
Fujii, Hiroki Tokushima University
南川, 慶二 Tokushima University 徳島大学 教育研究者総覧 KAKEN研究者をさがす
今田, 泰嗣 Tokushima University 徳島大学 教育研究者総覧 KAKEN研究者をさがす
We present that thioacetalization of aldehydes can be induced by blue light irradiation in the presence of a catalytic amount of riboflavin tetraacetate (RFTA) under aerobic conditions. Several control experiments have suggested that the reaction is more likely to be catalyzed by acidic species generated in situ during the light irradiation. We have proposed that single electron transfer from a thiol (RSH) to the excited state of RFTA can take place to give a one-electron oxidized thiol (RSH+•) and the one-electron reduced RFTA (RFTA–•), which can be trapped by molecular oxygen to be stabilized as Brønsted acids including the protonated RFTA–• (RFTAH•). Finally, we have demonstrated that such acidic species can be prepared in advance as a solution and used as Brønsted acid catalysts for not only the thioacetalization but also Mannich-type reactions.
The Royal Society of Chemistry
chemcom_56_42_5661.pdf 537 KB