A facile route to polysubstituted naphthalenes and benzofluorenols via scandium triflate- and triflic acid-catalyzed benzannulation of 2-(2-alkynylarylidene)-1,3-dicarbonyl compounds

This paper describes an efficient scandium triflate- and triflic acid-catalyzed benzannulation of 2-(2-alkynylarylidene)-1,3-dicarbonyl compounds to afford polysubstituted naphthalenes and benzo[a]fluorenols. The product selectivity could be tuned by subtle choice of the catalyst. An unprecedented process between alkynes and ketones is also explored.