Highly Enantioselective Synthesis of Fused Tri‐ and Tetrasubstituted Aziridines: aza‐Darzens Reaction of Cyclic Imines with α‐Halogenated Ketones Catalyzed by Bifunctional Phosphonium Salt. Issue 22 (29th April 2019)

• Record Type: Journal Article
• Authors: Pan, Jianke; Wu, Jia‐Hong; Zhang, Hongkui; Ren, Xiaoyu; Tan, Jian‐Ping; Zhu, Lixiang; Zhang, Hong‐Su; Jiang, Chunhui; Wang, Tianli
• Is Part Of: Angewandte Chemie international edition. Volume 58:Issue 22(2019)
• Page Start: 7425
• Page End: 7430
• Publication Date: 2019-04-29
• Subjects: aziridines -- chirality -- organocatalysis -- imines -- reaction mechanisms; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201900613
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: The first enantioselective aza‐Darzens reaction of cyclic imines with α‐halogenated ketones was realized under mild reaction conditions by using amino‐acid‐derived bifunctional phosphonium salts as phase‐transfer promoters. A variety of structurally dense tri‐ and tetrasubstituted aziridine derivatives, containing benzofused heterocycles as well as spiro‐structures, were readily synthesized in high yields with excellent diastereo‐ and enantioselectivities (up to >20:1 d.r. and >99.9 % ee ). The highly functionalized aziridine products could be easily transformed into different classes of biologically active compounds. Abstract : Pinch of salt : A highly enantioselective aza‐Darzens cyclization between cyclic imines and α‐halogenated ketones catalyzed by amino‐acid‐derived bifunctional phosphonium salts has been developed. A wide range of enantioenriched fused tri‐ and tetrasubstituted aziridines were synthesized with high yields and excellent diastereo‐ and enantioselectivities. Scale‐up synthesis and valuable transformations are also demonstrated.