Highly Regio‐, Diastereo‐, and Enantioselective [2+2+2] Cycloaddition of 1,6‐Enynes with Electron‐Deficient Ketones Catalyzed by a Cationic RhI/H8‐binap Complex

Two quaternary carbon centers are created in the title reaction to form fused dihydropyrans (see scheme). The same catalyst promotes the ortho functionalization of aryl ketones with 1,6-enynes with excellent regio- and enantioselectivity. Z=amide, C(CO2Me)2, O; E=CO2Et, Ac; R1=Me, aryl, CO2Me; R2=Me; R3=Me, CO2Et.