Synthesis of 2-Alkylideneisochromans by Cyclocarbonylative Sonogashira Reactions

In this study we used a tandem carbonylative Sonogashira reaction/cyclisation process to construct alkylidene-functionalized isochromans in high yields with complete stereoselectivity (only Z isomers were formed). The reaction was per-formed in the absence of a CuI co-catalyst with a small amount of PdCl2(PPh3)2 (0.2–0.5 mol-%), and aryl iodides bearing both electron-donating and electron-withdrawing substituents were successfully employed