title: Functionalization of 3,5,8-trichlorinated BODIPY dyes.
abstract: 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.
authors.affiliation: Department of Chemistry, Louisiana State University , Baton Rouge, Louisiana 70803, United States.
authors.forename: Haijun
authors.initials: H
authors.lastname: Wang
authors.forename: Frank R
authors.initials: FR
authors.lastname: Fronczek
authors.forename: M Graça H
authors.initials: MG
authors.lastname: Vicente
authors.forename: Kevin M
authors.initials: KM
authors.lastname: Smith
mesh_terms: D001593:Benzyl Compounds / Q000737:chemistry*; D001896:Boron Compounds / Q000737:chemistry*; D004396:Coloring Agents / Q000737:chemistry*; D018360:Crystallography, X-Ray; D005456:Fluorescent Dyes / Q000737:chemistry*; D006865:Hydrogenation; D008958:Models, Molecular; D015394:Molecular Structure; D011162:Porphobilinogen / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry
chemical_list: C000596036:2,5,9-trichlorodipyrromethene hydrochloride; C095489:4,4-difluoro-4-bora-3a,4a-diaza-s-indacene; D001593:Benzyl Compounds; D001896:Boron Compounds; D004396:Coloring Agents; D005456:Fluorescent Dyes; D011162:Porphobilinogen