Gold-catalyzed [5 + 2]-annulations of 1,3-diyn-1-amides with anthranils bearing no C(6)-substituents

This work reports the gold-catalyzed [5 + 2]-annulations of commonly used anthranils with 1,3-diynamides, yielding quiniline oxides as the main products. Previously, these [5 + 2]-annulations were operable only for ynamides and special anthranils bearing C(6)-substituents. The preferable chemoselectivity is attributed to the electron-withdrawing effects of aryltosylamides and alkynes, increasing the electrophilicity of the less hindered α-imino gold carbenes.