Synthesis and Chiroptical Properties of a Ring-Fused BODIPY with a Skewed Chiral π Skeleton

A twisted chiral boron-dipyrrin complex (BOD-IPY) was synthesized by oxidative annulation of the biphenyl units at the beta positions. The chiral BODIPY has two asymmetric carbons in the large planar skeleton, which Were generated upon the ring-fused reaction. Its pi-elongated and twisted structure resulted in the Cotton effect in the red region (lambda(max) = 614 nm, Delta epsilon = 60 M-1.cm(-1)) as well as the strong, fluorescence (Phi(F) = 0.73) and circularly polarized luminescence (CPL).