Mapping the reactivity of the quinoline ring-system – Synthesis of the tetracyclic ring-system of isocryptolepine and regioisomers. Issue 21 (24th May 2019)

• Record Type: Journal Article
• Authors: Håheim, Katja S.; Urdal Helgeland, Ida T.; Lindbäck, Emil; Sydnes, Magne O.
• Is Part Of: Tetrahedron. Volume 75:Issue 21(2019)
• Page Start: 2949
• Page End: 2957
• Publication Date: 2019-05-24
• Subjects: Natural product -- Suzuki-Miyaura cross-coupling -- Tandem C-H activation/C-N bond formation; Chemistry, Organic -- Periodicals; 547.005
• DOI: 10.1016/j.tet.2019.04.026
• Languages: English
• ISSNs: 0040-4020

Abstract

Abstract: Bromoquinolines (2-bromoquinoline – 8-bromoquinoline and 5-bromo-3-methoxyquinoline) and 2-aminophenylboronic acid hydrochloride were subjected to Suzuki-Miyaura cross-coupling conditions resulting in formation of the desired biaryl systems in good yields. The resulting biaryls were then subjected to palladium catalyzed CH activation/CN bond formation utilizing PdCl2 (dppf). The reactions revealed large differences in reactivity depending on the attachment point for the 2-aminophenyl group on the quinoline. The variation in the reactivity was rationalized based on the electron distribution around the quinoline ring-system. Graphical abstract: Image 1