FormylBODIPYs: Privileged Building Blocks for Multicomponent Reactions. The Case of the Passerini Reaction

Abstract

Eleven formyl-containing BODIPY dyes were prepared by means of either the Liebeskind-Srogl cross-coupling reaction or the Vilsmeier reaction. These dyes were used as components in the Passerini reaction to give highly substituted BODIPY dyes. A joined spectroscopic and theoretical characterization of the synthesized compounds was conducted to unravel the impact of the structural rigidity/flexibility on the photophysical signatures. These dyes were tested as fluorescent trackers for phagocytosis. Additionally, they proved to be useful to stain different blood cells with an intense and stable signal at a very low exposure time.

Ready Access to Molecular Rotors Based on Boron Dipyrromethene Dyes-Coumarin Dyads Featuring Broadband Absorption

“…Such sudden enhancement of the non-radiative rate constants was attributed at first sight to the deactivation channels afforded by the free rotation of the 8-coumarin fragment directly linked to the BODIPY. Indeed, low fluorescence efficiencies have been reported for BODIPYs bearing unconstrained aryls at the said key meso position [37][38][39], as supported by the theoretically conducted potential energy curves, which highlight the key role on the photophysics of the conformational freedom around the linkage bond between the BODIPY and the 8-aryls [40][41][42][43].…”

Modern Synthetic Avenues for the Preparation of Functional Fluorophores

“…Subsequent biological analysis identified PhagoGreen as a pH‐sensitive fluorophore for imaging phagocytic macrophages in vivo (Figure 2 H). An extension of this approach has been reported by Peña‐Cabrera and co‐workers with the derivatization of aldehyde‐functionalized BODIPYs in a Passerini MCR 14. With regard to the chromophore approach, Riva, Müller, and co‐workers recently described an Ugi MCR in which the initial adducts were converted into furo[2,3‐ c ]isoquinolines in a palladium‐catalyzed insertion/alkynylation/cycloisomerization cascade 15.…”

Moderne Strategien zur Synthese funktioneller Fluorophore

“…Bei einer nachfolgenden biologischen Analyse konnte PhagoGreen als pH‐empfindlicher Fluorophor zur In‐vivo‐Darstellung von phagozytischen Makrophagen identifiziert werden (Abbildung H). Eine Erweiterung dieses Ansatzes war die Derivatisierung von Aldehyd‐funktionalisierten BODIPYs mithilfe einer Passerini‐MCR durch Peña‐Cabrera und Mitarbeiter . Bezüglich der Chromophormethode beschrieben Riva, Müller et al.…”