Functionalization of 3,5,8-trichlorinated BODIPY dyes
© 2014 American Chemical Society. Catalytic hydrogenation of dibenzyl 5-dipyrroketone-2,9-dicarboxylates followed by decarboxylative iodination affords a 2,9-diiododipyrroketone which gives a 2,5,9-trichlorodipyrromethene hydrochloride after nucleophilic addition/elimination, with adventitious chloride to replace the two iodide groups. Treatment with BF3·Et2O gives a 3,5,8-trichloro-BODIPY that readily undergoes regioselective Stille coupling at the 8-position, or homo/mixed couplings at the 3,8- or 3,5- and 8-positions. Stepwise and controlled replacement of the 3,5- and 8-chlorine atoms using Stille reagents results in formation of a completely unsymmetrical trisubstituted BODIPY. Several examples of unsymmetrical BODIPYs were synthesized and characterized using this methodology. Structure features of new BODIPYs are discussed within the context of 14 new X-ray structures, and photophysical parameters of all new BODIPY compounds are reported and discussed.
Publication Source (Journal or Book title)
Journal of Organic Chemistry
Wang, H., Fronczek, F., Vicente, M., & Smith, K. (2014). Functionalization of 3,5,8-trichlorinated BODIPY dyes. Journal of Organic Chemistry, 79 (21), 10342-10352. https://doi.org/10.1021/jo501969z