Access to Polycyclic Indol(en)ines via Base‐Catalyzed Intramolecular Dearomatizing 3‐Alkenylation of Alkynyl Indoles. Issue 8 (25th June 2021)

• Record Type: Journal Article
• Authors: Lu, Lin; Zheng, Zuoliang; Yang, Yongjie; Liu, Bo; Yin, Biaolin
• Is Part Of: Chinese journal of chemistry. Volume 39:Issue 8(2021)
• Page Start: 2207
• Page End: 2212
• Publication Date: 2021-06-25
• Subjects: Dearomatization -- Domino reaction -- Alkynyl indole -- Synthetic method -- Cyclization; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/cjoc.202100164
• Languages: English
• ISSNs: 1001-604X

Abstract

Main observation and conclusion: Polycyclic indolines and indolenines were synthesized via base‐catalyzed intramolecular dearomatizing 3‐alkenylation reactions of alkynyl indoles 1 at room temperature. The base enhanced the nucleophilicity of the carbon at the 3‐position of the indole moiety, facilitating an exclusive 5‐ exo ‐dig cyclization reaction with the alkyne to form spiroindolenines 2. The imine functionality of 2 could undergo in situ nucleophilic addition to form spiroindolines 3 when R was a carbamoyl group or reduction to form spiroindolines 4 when R was H. Abstract : Polycyclic indolines and indolenines were synthesized via base‐catalyzed intramolecular dearomatizing 3‐alkenylation reactions of alkynyl indoles at room temperature.