Visible-Light-Induced Di-π-Methane Rearrangement of Dibenzobarrelene Derivatives

Abstract

It is demonstrated that the di-π-methane (DPM) rearrangement of carbonyl-substituted dibenzobarrelene (9,10-dihydro-9,10-ethenoanthracene) derivatives is induced by visible-light-induced triplet photosensitization with Ir(ppy)3, Ir(dFppy)3 or 1-butyl-7,8-dimethoxy-3-methylalloxazine as catalysts, whereas derivatives that lack carbonyl substituents are photoinert under these conditions. Notably, the products are formed almost quantitatively.