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.