We present the first examples of Suzukix2013;Miyaura cross-coupling reactions on meso-substituted trans-A2B-corrole derivatives with neutral, sterically hindered, inactivated and heteroaromatic boronic acids and esters, alkenylboronic acids, as well as quickly deboronating aryl boronic acids and benzo-condensated five membered heterocyclic boronic acids. In addition, we established a high-yield procedure for the Suzukix2013;Miyaura cross-coupling reaction of corroles with neutral boronic acids.
Due to the lability of the free-base corrole macrocycles, functionalization of the corrole periphery was performed with the corresponding Cu-metallated species. meso-Substituted trans-A2B-corrole can hence be regarded as highly versatile platform towards more sophisticated corrole systems.
X-ray structure analysis of a functionalized meso-substituted trans-A2B copper corrole exhibited the typical features of such a Cu-complex: short Nx2013;Cu distances and a saddled corrole configuration.
Moreover, we observed a sensitivity of the formal oxidation state of the coordinated copper ions towards Suzukix2013;Miyaura cross-coupling reaction conditions, where the central copper(III) ion approaches the characteristic features of a copper(II) species. This redox behaviour was examined by UV/vis absorption spectra, nuclear magnetic resonance (NMR) experiments and time-dependent density functional theoretical calculations.