Nucleophilic Substitution on (Pentafluorophenyl)dipyrromethane: A New Route to Building Blocks for Functionalized BODIPYs and Tetrapyrroles

The reaction of alcohols with (pentafluorophenyl)dipyrromethane (PFP-DPM) under basic conditions has been studied, giving access to the corresponding alkoxy-substituted DPMs. This method represents the first high-yielding substitution of PFP-DPM carried out with oxygen nucleophiles. Condensation of these prefunctionalized DPMs with aldehydes led to the respective trans-A2B2 porphyrins. This pathway allows a simple synthesis of multifunctionalized tetrapyrroles. Oxidation and boron complexation of these DPMs, on the other hand, led to meso-functionalized difluoroboraindacenes (BODIPYs). In addition, nucleophilic substitution of PFP-BODIPY with sodium azide led to a 4-azidophenyl derivative, thus further enhancing the scope of reactive sites suitable for subsequent transformations.