Ligand-Free Copper-Catalyzed Synthesis of Diaryl Thioethers from Aryl Halides and Thioacetamide - Tao, Chuanzhou; Lv, Aifeng; Zhao, Nan; Yang, Shuai; Liu, Xiaolang; Zhou, Jian; Liu, Weiwei; Zhao, Jing (Synlett, 2011)