Chemoselective Ru-II-Catalyzed Synthesis of Aryl Thiocyanates and Step-wise Double [2+2+2] Cycloadditions to 2-Aryl Thiopyridines

Ru-II-catalyzed intermolecular double [2+2+2] cycloadditions of 1,6-diynes and alkynylthiocyanates have been developed for the synthesis of 2-aryl thiopyridines. Aryl thiocyanates were isolated chemoselectively as a result of initial intermolecular [2+2+2] cycloaddition product. The method offers operational simplicity and is atom economical in nature.