Recent advances in the synthesis of [a]-benzo-fused BODIPY fluorophores.

This feature article summarizes the different strategies for the synthesis of [a]-benzo-fused BODIPYs that have been reported in the literature until 2018. These π-extended BODIPYs are promising fluorophores for bio-imaging and organic photovoltaic applications due to both their attractive photophysical properties in the near-infrared area and their higher (photo)chemical stability compared to conventional bis-styryl derivatives. The four main strategies described in this review can be used to access either directly the expected [a]-benzo-fused BODIPYs or through the di-/tetra-hydroisoindole.