Evaluation of Novel Fluorescence Probes for Conjugation Purposes Using the Traceless Staudinger Ligation

A robust and versatile method for the synthesis of various azide, alkyne and phosphane functionalized coumarin derivatives from the corresponding 7-amino and 7-hydroxy analogs for an application in bioorthogonal conjugation and labeling reactions like the Staudinger Ligation or the Huisgen-Click reaction is presented. Further, the convenient preparation of modified coumarins was performed and subsequent regio–/chemoselective labeling reactions delivered the desired biologically active derivatives in high yields. These new compounds may thus constitute attractive scaffolds for designing novel fluorescence building blocks for various challenging biolabeling applications.