Regiodivergent Intermolecular [3+2] Cycloadditions of Vinyl Aziridines and Allenes: Stereospecific Synthesis of Chiral Pyrrolidines

The first rhodium‐catalyzed intermolecular [3+2] cycloaddition reaction of vinyl aziridines and allenes for the synthesis of enantioenriched functionalized pyrrolidines was realized. [3+2] cycloaddition with the proximal C=C bond of N‐allenamides gave 3‐methylene‐pyrrolidines in high regio‐ and diastereoselectivity, whereas, 2‐methylene‐pyrrolidines were obtained as the major products by the cycloadditions of vinyl aziridines with the distal C=C bond of allenes. Use of readily available starting materials, a broad substrate scope, high selectivity, mild reaction conditions, as well as versatile functionalization of the cycloadducts make this approach very practical and attractive. Adding together rapidly: A regiodivergent synthesis of enantioenriched functionalized pyrrolidines, such as 2‐methylene‐ and 3‐methylene‐pyrrolidines, has been developed through a regioselective [3+2] cycloaddition of vinyl aziridines with allenes and N‐alleneamines, respectively. The reaction demonstrates general substrate scope, mild conditions, atom‐economy, and proceeds with complete chirality transfer.