Phosphine‐Catalyzed Enantioselective [3 + 2] Annulation of Allene‐1,3‐Dicarboxylates with Rhodanine‐Derived Alkenes

Despite notable advances achieved in the classic phosphine catalyzed allene–alkene [3 + 2] annulations, the scope of allenes mainly restrict to allenoates that bearing electron‐donating or neutral γ‐substituents. Reaction profile of electron‐withdrawing group‐substituted allenoates (e.g. allene‐1,3‐dicarboxylates (ADCs)) remained elusive yet in both symmetric and asymmetric patterns. Herein, we present a ( S )‐SITCP‐catalyzed [3 + 2] reaction of ADCs with rhodanine‐derived alkenes, providing efficient access of chiral spiro[rhodanine‐cyclopentene] derivatives in good yields (up to 98%) with excellent enantio‐ (up to 99% ee) and diastereoselectivity (up to > 20:1 dr). Notably, ADCs exhibited unparalleled reactivity and enantioselectivity against their γ ‐electron‐donating or neutral substituted analogs in this reaction.