B III -Subporphyrins Bearing Distorted Metal-Coordinating Straps: Cu II -Assisted meso -Fabrications.

B III -subporphyrins 4 , 5 , and 6 possessing metal-coordinating carbaporphyrin-like pockets were synthesized by Suzuki-Miyaura coupling reactions. Compounds 4 and 5 gave Pd II complexes 4-Pd and 5-Pd upon metalation with Pd(OAc) 2 but did not give either their Ni II or Cu II complexes. Conversely, 6 was expected to induce distorted square planar coordination because of its 2,5-di(pyrid-2-yl)pyrrole strap. Indeed reaction of 6 with Cu(OAc) 2 did not give its Cu II complex but produced meso -alkoxy and meso -phenoxy products in the presence of alcohols and phenol, possibly via Cu II -mediated C-H bond functionalization, which was further extended to meso -C-C bond-forming fabrications by using organoboronic acids. These Cu II -mediated C-H bond meso -fabrications are the first example for porphyrinoid substrates.