Design, Synthesis, Characterization and Evaluation of Near Infrared BODIPY Dyes for Various Applications

4,4-Difluoro-4-bora-3a,4a-diaza-5-indacene (BODIPY) have drawn a large number of research attention, for its numerous useful application in the fields of material and biology. Small modification of this well-known fluophore has been shown to optimize its photophysical and chemical properties. This work mainly focuses on functionalization of BODIPY cores with halogenated atoms, particularly iodine, and their subsequent post-functionalization reactions, mainly cross-coupling reaction and substitutions, for various further applications. Chapter 1 of this dissertation gives a general overview of BODIPYs including their synthetic strategies, post-functionalization, and how BODIPYs are utilized in many biological applications. Chapter 2 mainly focuses on the synthesis and characterization of 3,5-diiodo-BODIPYs’ and 2,3,5,6-tetraiodo-BODIPY’s cross coupling products, together with the best coupling reaction methodology developments. Chapter 3 presents various aromatic substitution reactions of 3,5-diiodo-BODIPYs and 2,3,5,6-tetraiodo-BODIPY. The methods are developed with the best solvents, temperature and equivalents of nucleophiles. Due to the high reactivity of the 3,5-iodines, 123I radio labeling reactions were also attempted to produce 123I exchanged BODIPYs within one hour. Chapter 4 investigates the aromatization reactions on â,â’-bicyclo-BODIPYs, and a full scan of all 3,5-substited groups shows that only electron withdrawing groups are stable during the aromatization reactions. Based on this conclusion, a bis(isothiocyanate)-BODIPY that emits in the near-IR region was prepared and conjugated to an EGFR-L1 peptide. Chapter 5 reports the synthesis of nitrophenyl BODIPYs, and their electrochemical properties were studied, in collaboration with Dr. Karl Kadish group from University of Houston. In the reductive area, reversible peaks are found, which are corresponded to the reductive reactions on the nitrophenyl units