Enantioselective annulation of enals with 2-naphthols by triazolium salts derived from l-phenylalanine

Abstract

A series of chiral triazolium salts have been synthesized from methyl L-phenylalaninate hydrochloride. The NHCs derived from this class of novel triazolium salts were found to be highly efficient catalysts in the annulation reaction of enals and 2-naphthols. These reactions proceeded with high chemoselectivity and wide substrate scope affording enantioenriched β-arylsplitomicins in good yields with up to 96% ee.