[5+2] Cycloaddition of 2‐(2‐Aminoethyl)oxiranes with Alkynes via Epoxide Ring‐Opening: A Facile Access to Azepines. Issue 35 (26th July 2016)

• Record Type: Journal Article
• Authors: Hu, Chao; Song, Ren‐Jie; Hu, Ming; Yang, Yuan; Li, Jin‐Heng; Luo, Shenglian
• Is Part Of: Angewandte Chemie international edition. Volume 55:Issue 35(2016)
• Page Start: 10423
• Page End: 10426
• Publication Date: 2016-07-26
• Subjects: azepines -- cycloaddition -- Lewis acids -- oxiranes -- ring opening; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201604679
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: A new FeCl3 and BF3 ⋅OEt2 co‐catalyzed tandem hetero‐[5+2] cycloaddition of 2‐(2‐aminoethyl)oxiranes with a wide range of alkynes, including terminal alkynes and alkyl‐substituted internal alkynes is presented. This is the first example of rapid and facile production of diverse 2, 3‐dihydro‐1 H ‐azepines through a sequence of epoxide ring‐opening, annulation, and dehydroxylation with broad substrate scope and exquisite selectivity control. Abstract : Access all azepines : An FeCl3 and BF3 ⋅OEt2 co‐catalyzed tandem hetero‐[5+2] cycloaddition of 2‐(2‐aminoethyl)oxiranes with alkynes is presented. This method provides a rapid and practical access to 2, 3‐dihydro‐1 H ‐azepines with exquisite chemo‐ and regiocontrol. The reaction is simple and has broad substrate scope and excellent functional‐group tolerance.