Synthesis and spectroscopic properties of beta,beta '-dibenzo-3,5,8-triaryl-BODIPYs

A series of beta,beta'-bicyclo-3,5-diaryl-BODIPYs were synthesized from the corresponding beta,beta'-bicyclo-3,5-diiodo-BODIPYs (1a, b) via Pd(0)-mediated Suzuki cross-coupling reactions in 82-92% yields. Subsequent aromatization with DDQ afforded the corresponding beta,beta'-dibenzo-aryl-BODIPYs, which showed red-shifted absorptions and emissions in the near-IR range. The dibenzo-appended BODIPYs showed characteristic H-1-, C-13-, B-11- and F-19-NMR shifts, and nearly planar conformations by X-ray crystallography.