Installations of Oligopyrrolic Straps Across the <i>Meso</i> ‐ and Axial‐Aryl‐Positions of B ^III Subporphyrin

Installations of oligopyrrin-straps at meso-bromo and B-(3-bromophenyl) B^III subporphyrin were attempted by Pd-catalyzed coupling reactions with α,α'-diborylated oligopyrins. While the reaction with a α,α'-diborylated dipyrrin gave a 2:2 macrocycle, those with α,α'-diborylated tripyrrin and BF₂-complexed tetrapyrrin gave tripyrrin- and BF₂-complexed tetrapyrrin-strapped B^III subporphyrins, respectively, as the first example bearing a strap across the meso- and axial-aryl-positions of B^III subporphyrin. The tripyrrin-strapped subporphyrin was shown to possess a Pd^II coordinating ability.