Base-Mediated and Silver-Catalyzed Divergent Synthesis of Hydroxynaphthalenamides and Phosphorylated Dihydronaphthylamides from Enone-Oxazolones

Abstract

An efficient divergent approach to functionalized naphthalene derivatives, the naphthalenamides, via base-mediated and silver-catalyzed cyclization has been developed using enoneoxazolones as the precursors. This protocol utilized base in methanol with heating to construct the corresponding hydroxynaphthalenamides 2 by a C−C bond formation, oxazolone ringopening, and aromatization in good yields. On the other hand, phosphorylated dihydronaphthylamides 3 were generated by using H-phosphonate as the phosphonating reagent in a silver-catalyzed cyclization involving the phospha-1,4-addition/intramolecular ring closure with concomitant C−P/C−C bond formation in good yields.