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. The synthesis of substituted polycyclic aromatic compounds has attracted considerable attention because of their increasing

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... lications as p-conjugated functional materials, such as organic semiconductors and luminescent materials. 1 Of particular interest is the synthesis of polyarylated aromatic cores owing to their enhanced ability to transport charge and fluorescent properties brought by the aryl groups. The synthetic methodologies for such structures have been developed recently, among which, transition metal-catalyzed ring construction of an aromatic substrate with two alkyne molecules has emerged particularly as an effective tool. 2 However, the di-or mono-functionalized aromatic substrates, such as aryl halide and aryl boronates, were required. Polyarylated heteroaromatic compounds, for instance, indoles, isoquinolines, benzothiazoles and pyridines, could be obtained by catalytic activation of C-H bonds with subsequent C-C bond formation, 3 which is one of most valuable endeavours from atom-and step-economic points of view. 4 Miura et al. has obtained naphthalene derivatives via the dual C-H bond activation of 1-phenylpyrazole catalyzed by a rhodium complex in the presence of excessive Cu(OAc) 2 as the oxidant. 5a However, the requirement of Cu(OAc) 2 as the oxidant, an inert gas atmosphere and ortho-azole as the directing group, which requires several steps for installation and detachment, may limit its structural modification and applications. Thus, cycloaromatization of alkynes with arenes through activation of C-H bonds still remains challenge. 5 Based on the ability of N-acetyl anilines to undergo ortho-metalation, 6 the ease to be de-protected and modified, and stability of Pd(OAc) 2 under an air atmosphere, here we studied the synthesis of 5,6,7,8-tetraaryl-N-acetyl-1-aminonaphthalenes from N-acetyl anilines with two alkyne molecules through dual C-H bond activation catalyzed by Pd(OAc) 2 using a cheap oxidant under mild conditions. The products with fluorescent properties were obtained.