Catalytic Asymmetric [8+2] Cycloaddition: Synthesis of Cycloheptatriene‐Fused Pyrrole Derivatives

Add a ring: A catalytic asymmetric [8+2] cycloaddition reaction of azaheptafulvenes with alkylidene malonates was developed. When employing catalytic amounts of a chiral N,N′-dioxide L–NiII complex, the reaction afforded functionalized cycloheptatriene-fused pyrrole derivatives in excellent yields (up to 99 %), diastereoselectivities (>95:5 d.r.), and enantioselectivities (91–97 % ee) under mild conditions.