title: Suzuki-Miyaura cross-coupling reaction on copper-trans-A(2)B corroles with excellent functional group tolerance.
abstract: The palladium-catalyzed Suzuki-Miyaura cross-coupling reaction has been investigated on meso-substituted trans-A(2)B-corrole using tailored Pd-catalyst systems.We present the first examples of Suzuki-Miyaura cross-coupling reactions on meso-substituted trans-A(2)B-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 Suzuki-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-A(2)B-corrole can hence be regarded as highly versatile platform towards more sophisticated corrole systems.X-ray structure analysis of a functionalized meso-substituted trans-A(2)B copper corrole exhibited the typical features of such a Cu-complex: short N-Cu distances and a saddled corrole configuration.Moreover, we observed a sensitivity of the formal oxidation state of the coordinated copper ions towards Suzuki-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.
authors.affiliation: Institute of Inorganic Chemistry, Johannes Kepler University Linz (JKU), Altenberger Straβe 69, A-4040 Linz, Austria.
authors.forename: Michael
authors.initials: M
authors.lastname: König
authors.forename: Lorenz Michael
authors.initials: LM
authors.lastname: Reith
authors.forename: Uwe
authors.initials: U
authors.lastname: Monkowius
authors.forename: Günther
authors.initials: G
authors.lastname: Knör
authors.forename: Klaus
authors.initials: K
authors.lastname: Bretterbauer
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Schoefberger