Photocatalytic oxygenation of olefins with oxygen: Isolation of 1,2-dioxetane and the photocatalytic O–O bond cleavage

Abstract

Formation of 1,2-dioxetane of tetraphenylethylene (TPE) occurs via formation of the electron transfer state of 9-mesityl-10-methylacridinium ion (Acr +-Mes) under visible light irradiation, followed by electron transfer from TPE to the Mes + moiety together with electron transfer from the Acr moiety to O 2, and the subsequent radical coupling between TPE + and O 2 − to yield the corresponding 1,2-dioxetane. The dioxetane thus formed was isolated using column chromatography. Photooxygenation of stilbene derivatives is also efficiently catalyzed by Acr +-Mes, accompanied by efficient cis– trans isomerization, to afford the corresponding benzaldehydes via electron transfer from Acr -Mes + to stilbene derivatives and oxygen.