Photocycloadditions of benzene derivatives and their systematic application to organic synthesis

Abstract

Photocycloadditions of benzene derivatives with alkenes play an important role as key steps in organic synthesis. Intramolecular reactions have been most frequently studied in this context. Often, meta or [2 + 3] photocycloadditions take place in competition with ortho or [2 + 2] additions. The influence of the substitution pattern and the spin multiplicity of the excited state on the outcome of these reactions is discussed. A topological analysis permitting a systematic application of the [2 + 3] photocycloadditions to the total synthesis of natural products is presented and a selection of corresponding syntheses is discussed. More recently the [2 + 2] photocycloaddition and consecutive rearrangements on organic synthesis have been published. Some approaches in the context of asymmetric synthesis have also been reported.