Formation of a new benzotriquinane skeleton via intramolecular photocycloaddition reactions of a phenylethynes moiety to a 1-cyanonaphthalene ring system

摘要

Photoirradiation of l-cyano-2-(2,2-dicyano-5-phenylpentyn-4-yl)-naphthalene and its analogues promotes sequential intramolecular 2π + 2π photocycloaddition and cyclobutene ring opening to form benzocyclooctatetraenes, which are then transformed to benzotriquinanes in good yields via a photochemical transannular cyctization process.