5 BODIPY Dyes and Their Analogues
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Fig. 5.10 Representative synthetic method for synthesis of asymmetric BODIPY dyes. Substituents
on the pyrrole rings have been omitted for clarity
5.2.3.3 Functionalization of BODIPY Core
Selective functionalization of the BODIPY chromophore is possible through the
introduction of various substituents at desired positions by regioselective postsynthetic functionalization (Boens et al. 2015; Lakshmi et al. 2016; Bodio and Goze
2019; Clarke and Hall 2019) (Fig. 5.11).
Functionalization of meso-position
Introduction of substituents at the meso-position of BODIPY dyes can be achieved
by Pd-catalyzed cross-coupling (Suzuki (Leen et al. 2012), Stille (Leen et al. 2012),
Sonogashira (Leen et al. 2012), and Negishi coupling (Palao et al. 2016)) of mesohalogenated BODIPY dyes (Fig. 5.12). The Liebeskind-Srögl (Peña-Cabrera et al.
2007) cross-coupling of meso-methylthio substituted BODIPY dyes is also useful to
introduce substituents at the meso-position; the reaction characteristically proceeds
under neutral conditions. Additionally, nucleophilic aromatic substitution (S N Ar) of
meso-chlorinated BODIPY dyes achieves the introduction of N, O, and S atoms (Leen
Fig. 5.11 Regioselective post-synthetic functionalization of BODIPY dyes