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

• Published in: Angewandte Chemie International Edition Vol. 55; no. 36; pp. 10844 - 10848
• Main Authors: Lin, Tao-Yan, Zhu, Chao-Ze, Zhang, Peichao, Wang, Yidong, Wu, Hai-Hong, Feng, Jian-Jun, Zhang, Junliang
• Format: Journal Article
• Language: English
• Published: WEINHEIM Blackwell Publishing Ltd 26.08.2016; Wiley; Wiley Subscription Services, Inc
• Edition: International ed. in English
• Subjects: allenes; Catalysis; Chemical synthesis; Chemistry; Chemistry, Multidisciplinary; chirality; Cycloaddition; heterocycles; Methylene; Physical Sciences; Rhodium; Science & Technology; Selectivity; ASYMMETRIC-SYNTHESIS; ACID; chirality; RING EXPANSIONS; INTRAMOLECULAR HYDROAMINATION; DIVERGENT SYNTHESIS; DIAZO-COMPOUNDS; ALLENAMIDES; REARRANGEMENT; allenes; cycloaddition; heterocycles; ISOCYANATES; rhodium
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.201605530

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.