Construction of Cationic Azahelicenes: Regioselective Three‐Component Annulation Using In Situ Activation Strategy. Issue 52 (26th October 2020)

• Record Type: Journal Article
• Authors: Wang, Zhishuo; Jiang, Linfeng; Ji, Jinwen; Zhou, Fulin; Lan, Jingbo; You, Jingsong
• Is Part Of: Angewandte Chemie international edition. Volume 59:Issue 52(2020)
• Page Start: 23532
• Page End: 23536
• Publication Date: 2020-10-26
• Subjects: annulations -- C−H activation -- fluorescence -- helicenes -- multicomponent reaction; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.202010051
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: Described herein is a strategy to construct cationic azahelicenes through the three‐component annulation reaction of isoquinoline, indole, and 1, 2‐dichloroethane (DCE), in which DCE serves as an in situ activating agent for C1−H activation of isoquinoline, a vinyl equivalent, and a solvent. This in situ activation annulation reaction features a facile one‐step synthesis and complete regioselectivity. The complete regioselectivity of C1 over C3 for the isoquinoline ring paves a path to the helical structure in a highly ordered sequence. One of the synthesized ionic [5]azahelicenium fluorophores exhibits the potential to serve as a mitochondria‐targeted biomarker with good photostability and low cytotoxicity. Abstract : A three‐component annulation reaction of (iso)quinoline, indole, and 1, 2‐dichloroethane in one step affords a family of cationic azahelicenes. This in situ activation protocol features a facile one‐step synthesis and complete regioselectivity.