Regioselective Synthesis of 4-Fluoroalkyl Isoquinolines

Significance

The palladium-catalyzed regioselective heteroannulation of fluoroalkynes with various 2-iodobenzylidenamines to produce the corresponding 4-fluoroalkyl isoquinolines in moderate to high yields is reported. The versatility of the reaction is evidenced in the participation of benzylidenamines with both electron-withdrawing and -donating substituents. However, the reaction is significantly slower when alkynes bearing an electron-withdrawing aryl substituent (NO₂) or an aliphatic chain are used.