8-Alkenylborondipyrromethene dyes. General synthesis, optical properties, and preliminary study of their reactivity

A new series of 8-alkenylBODIPY dyes were prepared via the Liebeskind–Srogl cross-coupling starting from 8-thiomethyl-substituted BODIPY. Ten derivatives were prepared using alkenylboronic acids in good to excellent yields (79–97%), and one additional example was prepared from an alkenylstannane in 74% yield. The products display Michael acceptor-like reactivity. The alkenyl fragment quenches the fluorescence of the BODIPY core, which is turned back on by reducing the double bond.