Palladium catalyzed synthesis of highly substituted naphthalenes via direct ring construction from amides with alkynes

The direct ring construction of amides with alkynes catalyzed by palladium acetate with cheap oxidant under an air atmosphere has been realized. A variety of novel highly substituted naphthalenes 3a-3l have been prepared chemo- and regioselectively in 55-97% yields under mild conditions. Product 3j emits intense blue luminescence peaked at 435 nm with a good blue purity.