Photochemically catalyzed ring opening of oxiranecarbonitriles and [3+2] cycloaddition with olefins: synthesis of polysubstituted tetrahydrofurans

Photoinduced electron transfer catalyzed ring opening of aryl-substituted oxiranecarbonitriles via Cβ–O bond cleavage was achieved using 2,4,6-triphenylpyrylium tetrafluoroborate (TPT) as a sensitizer and subsequent [3+2] cycloaddition reaction with electron-rich olefins afforded polysubstituted tetrahydrofurans in good to moderate yields.