Intramolecular addition reactions during heteroatom directed photoarylation

The intramolecular addition reactions of phototransient species generated upon heteroatom directed photoarylation were investigated. Novel temperature effects were observed for both the photocyclization and intramolecular addition reactions. Moreover, the addition products observed differ considerably from the (3 + 2) cycloadducts which were obtained upon intermolecular addition to the phototransient species.