Controllable Tandem [3+2] Cyclization of Aromatic Aldehydes with Maleimides: Rhodium(III)-Catalyzed Divergent Synthesis of Indane-Fused Pyrrolidine-2,5-dione.

Controllable rhodium(III)-catalyzed tandem [3+2] cyclization of aromatic aldehydes with maleimides is developed for the divergent synthesis of stereoselective indane-fused pyrrolidine-2,5-dione. Switchable access to different products could be achieved by employing different additives and varying the reaction time. This atom-economic transformation proceeds efficiently via the C-H bond activation directed by weakly coordinating aldehydes and is characterized by exclusive stereoselectivity, air atmosphere, and being free of nitrogen-based transient directing groups.