Nakayama Kaii, Maeta Naoya, Horiguchi Genki, Kamiya Hidehiro, Okada Yohei
Department of Chemical Engineering , Tokyo University of Agriculture and Technology , 2-24-16 Naka-cho , Koganei, Tokyo 184-8588 , Japan.
Org Lett. 2019 Apr 5;21(7):2246-2250. doi: 10.1021/acs.orglett.9b00526. Epub 2019 Mar 27.
Radical cation Diels-Alder reactions by titanium dioxide (TiO) photocatalysis in lithium perchlorate/nitromethane solution are described. TiO photocatalysis promotes reactions between electron-rich dienes and dienophiles, which would otherwise be difficult to accomplish due to electronic mismatching. The reactions are triggered by hole oxidation of the dienophile and are completed by the excited electron reduction of the radical cation intermediate at the dispersed surface in the absence of any sacrificial substrate.
描述了在高氯酸锂/硝基甲烷溶液中通过二氧化钛（TiO₂）光催化进行的自由基阳离子狄尔斯-阿尔德反应。TiO₂光催化促进富电子二烯和亲双烯体之间的反应，否则由于电子不匹配这些反应很难完成。这些反应由亲双烯体的空穴氧化引发，并在没有任何牺牲底物的情况下，通过分散表面上自由基阳离子中间体的激发电子还原而完成。
