Flexible Synthesis of Fused Benzofuran Derivatives by Rhodium-Catalyzed [2+2+2] Cycloaddition with Phenol-Linked 1,6-Diynes

A flexible and convenient synthesis of fused benzofuran derivatives has been achieved under mild reaction conditions by cationic rhodium(I)/H-8-BINAP complex-catalyzed [2 + 2 + 2] cycloadditions of phenol-linked 1,6-diynes with alkynes and nitriles.