Cu(II)-Catalyzed 6π-Photocyclization of Non-6π Substrates.

This research successfully achieved a Cu(II)-catalyzed 6π-photocyclization of non-6π substrates. The photoenolization converts ortho-alkylphenyl alkynl ketones into a triene-type intermediate which undergoes the subsequent 6π-photocyclization to give naphthol as the final product. Cu(II) catalyst facilitates both photoenolization and 6π-photocyclization. This research highlighted the tandem reaction strategy and the importance of metal catalysis in photochemistry.