Synthesis of a Toolbox of Clickable Rhodamine B Derivatives

An efficient method for the large-scale preparation of rhodamine B clickable derivatives has been developed. Starting from inexpensive rhodamine B as the starting material it was possible to functionalize the carboxylic functionality of rhodamine B with an azide, a strained-alkyne, a substituted triphenylphosphine, a thiol, and a maleimide. Through the synthetic strategy it was possible to obtain stable and pure clickable rhodamine compounds that can be readily used not only for chemoselectively probing biomolecules, but also for materials science.