K 2 S 2 O 8 ‐induced Dearomative Spirocyclization of Biaryl Ynones with Diselenides toward Selenated Spiro[5.5]trienones

A metal‐free radical spirocyclization of biaryl ynones with diselenides is developed, providing selenated spiro[5.5]trienones in moderate to good yields. This protocol features broad substrate scope, good functional group tolerance and free of an inert atmosphere. Furthermore, the replacement of diselenides with ditellurides is also applicable for this reaction to construct the corresponding tellurium‐substituted spiro[5.5]trienones.