Catalytic reductive ring opening of epoxides enabled by zirconocene and photoredox catalysis
Kazuhiro Aida, Marina Hirao, Aiko Funabashi, Natsuhiko Sugimura, Eisuke Ota, Junichiro Yamaguchi
Abstract
The reductive ring opening of epoxides is a powerful transformation to convert readily accessible epoxides into a diverse array of valuable alcohols, including pharmaceuticals, agrochemicals, and functional polymers. Although significant progress has been made, the established methods were limited to titanocene-catalyzed reactions. Herein, we report an unprecedented zirconocene-catalyzed ring opening of epoxide enabled by photoredox catalysis. Compared with the conventional ring-opening methods, the present protocol exhibited reverse regioselectivity to afford more substituted alcohols via putative less-stable radicals. This reaction is remarkably mild and smoothly cleaves C–O bonds in molecules with a variety of functional groups, including natural products. We believe that the finding that changing the metal center in metallocene influences the energy profile of ring opening is a significant advance and provides a new perspective in radical chemistry with group IV metals.