Lewis acid assisted decomplexation of F-BODIPYs to dipyrrins

Abstract

A simple synthetic route was developed for the decomplexation of F-BODIPYs (fluorine-substituted boron–dipyrromethenes) to afford dipyrrins in high yields. This was achieved by treating the F-BODIPYs with different Lewis acids such as ZrCl4, TiCl4, AlCl3, Sc(OTf)3 or SnCl4 in CH3CN/CH3OH under refluxing conditions. This synthetic strategy was efficient for different types of F-BODIPYs such as meso-aryl-substituted BODIPYs, 3-pyrrolyl BODIPYs, functionalized 3-pyrrolyl BODIPYs, π-extended pyrrolyl BODIPYs, sterically crowded BODIPYs and the BF2 complex of 25-oxasmaragdyrin