Insertion-coupling-cycloisomerization domino synthesis and cation-induced halochromic fluorescence of 2,4-diarylpyrano[2,3-b]indoles.
2,4-Diarylpyrano[2,3-b]indoles are formed via a Pd-Cu-catalyzed insertion-coupling-cycloisomerization domino reaction in moderate yields. Although the tricyclic systems are nonfluorescent in solution, protonation, quaternation, or complexation with metal ions induces intense green luminescence. Most strikingly, selective halochromic fluorescence of zinc and magnesium over calcium ions classify the title compounds as metal-selective luminescence sensors.
Schönhaber
Jan
J
Institut für Organische Chemie und Makromolekulare Chemie, Heinrich-Heine-Universität Düsseldorf, Universitätsstr. 1, D-40225 Düsseldorf, Germany.
Frank
Walter
W
Müller
Thomas J J
TJ
D002412:Cations / Q000737:chemistry; D018360:Crystallography, X-Ray; D003500:Cyclization; D005456:Fluorescent Dyes / Q000138:chemical synthesis*; D007211:Indoles / Q000737:chemistry*; D007536:Isomerism; D008745:Methylation; D008958:Models, Molecular; D015394:Molecular Structure
D002412:Cations; D005456:Fluorescent Dyes; D007211:Indoles