Highly Regio‐, Diastereo‐, and Enantioselective Assembly of Azepino[2,3‐b]indoles via Palladium‐Catalyzed [4 + 3] Cycloaddition

• Published in: Chinese journal of chemistry Vol. 38; no. 12; pp. 1571 - 1574
• Main Authors: Yang, Wu‐Lin, Huang, Zesheng, Liu, Yang‐Zi, Yu, Xingxin, Deng, Wei‐Ping
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY‐VCH Verlag GmbH & Co. KGaA 01.12.2020; Wiley
• Subjects: [4+3] Cycloaddition; Asymmetric catalysis; Azepino[2,3‐b]indole; Chemistry; Chemistry, Multidisciplinary; Palladium; Physical Sciences; Science & Technology; Synthetic method; Trimethylenemethane; Azepino[2,3-b]indole; AZEPINOINDOLES; ASYMMETRIC-SYNTHESIS; REAGENTS; AZOMETHINE YLIDES; Palladium; AZIRIDINES; Asymmetric catalysis; 3+4 ANNULATION; HETEROCYCLES; Trimethylenemethane; Synthetic method; 3-DIAZOINDOLIN-2-IMINES; ACCESS; [4+3] Cycloaddition
• ISSN: 1001-604X; 1614-7065
• DOI: 10.1002/cjoc.202000264

Summary of main observation and conclusion A palladium‐catalyzed asymmetric [4 + 3] cycloaddition of trimethylenemethanes and indoline‐derived aza‐dienes has been developed. The potential [3 + 2] side pathway was completely suppressed in the process. This protocol provides an efficient access to azepino[2,3‐b]indoles bearing two vicinal stereocenters in generally excellent diastereo‐ and enantioselectivities (up to > 20 : 1 dr, 99% ee). Palladium‐catalyzed asymmetric [4 + 3] cycloaddition of trimethylenemethanes and indoline‐ derived aza‐dienes was established, affording azepino[2,3‐b]indoles in generally excellent diastereo‐ and enantioselectivities (up to > 20 : 1 dr, 99% ee).