Functionalization of BODIPY with enamines and amines through one-step reactions with ethylamines

Direct functionalization of meso-C6F5 BODIPY with various enamines and amines at the pyrrolic α-position has been achieved by reacting the BODIPY with ethylamines in acetonitrile using BPO (benzoyl peroxide) as an additive under aerobic atmosphere at room temperature. The reaction modes of the products can be effectively modulated by the substituents on the ethylamines, affording three different types of products with enamine and amine moieties regioselectively attached at the pyrrolic α position and the para-position of the meso-C6F5 group. The spectroscopic properties are effectively modulated by the ICT effect from the electron-donating enamino or amino groups to the electron-withdrawing BODIPY core and the pentafluorophenyl moiety, with the absorption and emission maxima varying in the ranges of 497–602 and 535–650 nm, respectively. These results compose an efficient method for synthesizing enamine and amine functionalized BODIPYs. A novel one-step approach using ethylamines for synthesizing enamine and amine functionalized BODIPYs with tunable absorption has been developed. [Display omitted] •A novel approach for synthesizing enamine functionalized BODIPYs.•Various reaction modes revealed by the crystal structures.•Tunable absorption modulated by the substituents on the ethylamines.