Practical Synthesis of α‐Trifluoromethylated Pyridines Based on Regioselective Cobalt‐Catalyzed [2+2+2] Cycloaddition using Trifluoromethylated Diynes with Nitriles

Abstract Regioselective cobalt‐catalyzed [2+2+2] cycloaddition using fluorine‐containing diynes with nitriles was described. Cycloaddition of fluorinated diynes with nitriles under the influence of CoCl 2 (phen), zinc bromide, and zinc dust in dichloroethane at 80 °C for 3 h took place smoothly, exclusively affording the corresponding α ‐fluoroalkylated pyridines in excellent yields. In addition, dinitriles as substrate were also found to be suitable for this reaction, giving the corresponding fluoroalkylated bipyridine derivatives in excellent yields. magnified image