Dissimilar-at-boron N-BODIPYs: From light-harvesting multichromophoric arrays to CPL-bright chiral-at-boron BODIPYs

We report a workable and easy approach for the direct post-multifunctionalization of common BODIPYs (F-BODIPYs) with minimal interference to the starting photophysical behavior. It entails the easy transformation of an F-BODIPY into the corresponding N-BODIPY by using a dissimilarly-N,N′-disubstituted bis(sulfonamide), which is easily obtained from ethane-1,2-diamine. This approach is exemplified by the rapid synthesis of a selected battery of unprecedented dissimilar-at-boron N-BODIPYs, which are rationally designed to act as efficient multichromophoric arrays for light harvesting by excitation energy transfer, as specific bioprobes for fluorescent imaging, or as efficient chiroptical dyes exhibiting visible circular dichroism and circularly polarized luminescence. Noticeably, this approach has led to the synthesis of the first CPL-bright chiral-at-boron BODIPYs, a significant novelty in BODIPY chemistry and CPL emitters.