Synthesis and properties of chiral fluorescent helicene-BODIPY conjugates

A series of chiral fluorescent helicene-BODIPY conjugates was prepared by the regioselective formylation of aza[4]helicene precursors and then an efficient one-pot two-step BODIPY synthesis (13 examples, 28-82%). Fused conjugates exhibit absorption and fluorescence properties (phi(F)30-45%) in the red visible domain, and a CPL signature could be measured at 605 nm (g(lum)+/- 5 x 10(-4)). Photophysical and electronic properties were investigated and rationalized through first principles.