catalyzed reaction of aryl halides with sodium t-butoxide effectively to give aryl t-butylethers. The high catalytic activity realized the formation of aryl t-butylethers from not only electron-deficient aryl halides but also electron-rich aryl halides. Moreover, the first synthesis of 4-chlorobenzofuran was attained utilizing the selective mono-t-butoxylation of aryl dihalide.