Clickable azide-functionalized bromoarylaldehydes - synthesis and photophysical characterization

Dominik Göbel; Marius Friedrich; Enno Lork; Boris J Nachtsheim

doi:10.3762/bjoc.16.139

Clickable azide-functionalized bromoarylaldehydes - synthesis and photophysical characterization

Beilstein J Org Chem. 2020 Jul 14:16:1683-1692. doi: 10.3762/bjoc.16.139. eCollection 2020.

Authors

Dominik Göbel¹, Marius Friedrich^{1

2}, Enno Lork³, Boris J Nachtsheim¹

Affiliations

¹ Institute for Organic and Analytical Chemistry, University of Bremen, Leobener Straße 7, 28359 Bremen, Germany.
² Department of Organic Chemistry, Technical University Kaiserslautern, Erwin-Schrödinger-Straße Geb.54, 67663 Kaiserslautern, Germany.
³ Institute for Inorganic and Crystallographic Chemistry, University of Bremen, Leobener Straße NW2, 28359 Bremen, Germany.

Abstract

Herein, we present a facile synthesis of three azide-functionalized fluorophores and their covalent attachment as triazoles in Huisgen-type cycloadditions with model alkynes. Besides two ortho- and para-bromo-substituted benzaldehydes, the azide functionalization of a fluorene-based structure will be presented. The copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) of the so-synthesized azide-functionalized bromocarbaldehydes with terminal alkynes, exhibiting different degrees of steric demand, was performed in high efficiency. Finally, we investigated the photophysical properties of the azide-functionalized arenes and their covalently linked triazole derivatives to gain deeper insight towards the effect of these covalent linkers on the emission behavior.

Keywords: bromoarylaldehydes; click-chemistry; fluorenes; fluorescence; phosphorescence.