Double click macrocyclization with Sondheimer diyne of aza-dipyrrins for B-Free bioorthogonal imaging

Sequential azide/diyne cycloadditions proved highly effective for the macrocyclization of a bis-azido aza-dipyrrin. Macrocyclic aza-dipyrrin could be produced in 30 min at rt in water with changes in fluorescence intensity and lifetimes measurable upon reaction. Live cell microscopy showed that aza-dipyrrins were suitable for confocal and STED super-resolution imaging and a bioorthogonal response to macrocyclization could be detected in cellular compartments. These results will encourage a broader examination of the sensing and imaging uses of aza-dipyrrins.

Automated summary

Sequential azide/diyne cycloadditions were used for efficient macrocyclization of a bis-azido aza-dipyrrin. Macrocyclic aza-dipyrrin could be obtained in just 30 minutes at room temperature in water, with measurable changes in fluorescence intensity and lifetimes during the reaction. Live cell microscopy demonstrated the suitability of aza-dipyrrins for confocal and STED super-resolution imaging, and a bioorthogonal response to macrocyclization was observed in cellular compartments. These findings will encourage further exploration of the sensing and imaging applications of aza-dipyrrins.