Boron dipyrromethene derivatives

Zhang X, Xiao Y, Qian X. Highly efficient energy transfer in the light harvesting system composed of three kinds of boron-dipyrromethene derivatives. Org Letters 2008 10 29-32. 

Fluorescence imaging is the most powerful technique currently available for continuous observation of the dynamic intracellular processes of living cells. Fluorescein is widely employed as the core of various fluorescence probes used in imaging important biological effectors. Despite the extensive use of fluorescein derivatives and the importance of the applications, the mechanism that controls the quantum yield of fluorescence has not been fully established. I report herein photoinduced electron transfer (PeT) mechanism that can control the fluorescence quantum yields of fluorescein and boron dipyrromethene (BODIPY) derivatives. 

Mechanisms of the nucleophilic substitution of hydrogen have been reviewed, and there has been a report of the synthesis of nitroaryl derivatives of glycine using the oxidative pathway. An example of the vicarious substitution mechanism is the formation of (13), a 3-styryl-substituted boron dipyrromethene, by reaction of a... 

Let us consider an example. Time-resolved methods allow a detailed description of excited state and of their useful properties, e.g., as sensitizers. A popular class of oxygen sensitizers is that of boron dipyrromethene (9, BODIPY) and their derivatives, e.g., the diiodo derivative 10 in Scheme 6.4, in view of applications such as photodynamic therapy [24]. 

Figure 8 View of a Zn(II)-based MOF that combines a tetracarboxylate-derived porphyrin with a bis-pyridyl substituted BODIPY (difluoro-boron-dipyrromethene) ligand. (Reprinted with permission from Ref 41. Copyright (2011) American Chemical Society.)...

Boron-dipyrromethene (BODIPY) derivatives have attracted attention as fluorescent stable dyes bearing sharp absorption bands with high molar extinction values and emission bands... 

BODIPY has a rigid structure, which can be formed by boron insertion with BF3 OEt2 into a dipyrromethene unit. Generally, the synthesis of BODIPY derivatives starts from the dipyrromethene precursor. It is relatively easy to construct the precursor using the well-known pyrrole condensation reaction. There are two common synthetic strategies, especially for symmetric and unsymmetric BODIPY cores, respeetively. 

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