Synthesis of meso‐CF3‐Substituted BODIPY Compounds with Redshifted Absorption

The one‐pot synthesis of meso‐CF3‐substituted boron–dipyrromethene (BODIPY) compounds is achieved for the first time through the condensation of pyrroles with CF3COOH in the presence of PhSiCl3. The PhSiCl3 plays a vital role, as it provides the source of Cl– ions for the generation of acyl chloride. X‐ray crystallographic analysis revealed that the core skeleton of meso‐CF3‐BODIPY becomes nonplanar and twisted owing to the introduction of the –CF3 group. The introduction of the –CF3 group to the BODIPY core results in a remarkable bathochromic shift of the absorption to the near‐infrared (NIR) region. A meso‐CF3‐BODIPY with dimethylamino groups is a turn‐on fluorescent probe for pH, and the singlet‐oxygen generation of dibromo‐substituted meso‐CF3‐BODIPY is more effective (ca. 2.4‐fold rate enhancement) than that of the parent meso‐CF3‐BODIPY.