title: Palladium(ii)-Acetylacetonato Complexes with Mesoionic Carbenes: Synthesis, Structures and Their Application in the Suzuki-Miyaura Cross Coupling Reaction.
abstract: A series of novel palladium(ii) acetylacetonato complexes bearing mesoionic carbenes (MICs) have been synthesized and characterized. The synthesis of the complexes of type (MIC)Pd(acac)I (MIC = 1-mesityl-3-methyl-4-phenyl-1,2,3-triazol-5-ylidene (1), 1,4-(2,4,6-methyl)-phenyl-3-methyl-1,2,3-triazol-5-ylidene (2), 1,4-(2,6-diisopropyl)-phenyl-3-methyl-1,2,3-triazol-5-ylidene (3); acac = acetylacetonato) via direct metalation starting from the corresponding triazolium iodides and palladium(ii) acetylacetonate is described herein. All complexes were characterized by ¹H- and13C-NMR spectroscopy and high resolution mass spectrometry. Additionally, two of the complexes were characterized by single crystal X-ray crystallography confirming a square-planar coordination geometry of the palladium(ii) center. A delocalized bonding situation was observed within the triazolylidene rings as well as for the acac ligand respectively. Complex2was found to be an efficient pre-catalyst for the Suzuki-Miyaura cross coupling reaction between aryl-bromides or -chlorides with phenylboronic acid.
authors.affiliation: Institut für Chemie und Biochemie, Anorganische Chemie, Freie Universität Berlin, Fabeckstraße 34-36, Berlin D-14195, Germany. Lara.Hettmanczyk@fu-berlin.de.
authors.forename: Lara
authors.initials: L
authors.lastname: Hettmanczyk
authors.affiliation: Institut für Chemie und Biochemie, Anorganische Chemie, Freie Universität Berlin, Fabeckstraße 34-36, Berlin D-14195, Germany. bianca.schmid@chem.tu-berlin.de.
authors.forename: Bianca
authors.initials: B
authors.lastname: Schmid
authors.affiliation: Institut für Chemie und Biochemie, Anorganische Chemie, Freie Universität Berlin, Fabeckstraße 34-36, Berlin D-14195, Germany. Stephan.Hohloch@web.de.
authors.forename: Stephan
authors.initials: S
authors.lastname: Hohloch
authors.affiliation: Institut für Chemie und Biochemie, Anorganische Chemie, Freie Universität Berlin, Fabeckstraße 34-36, Berlin D-14195, Germany. biprajit.sarkar@fu-berlin.de.
authors.forename: Biprajit
authors.initials: B
authors.lastname: Sarkar
mesh_terms: D002384:Catalysis; D057930:Click Chemistry; D056831:Coordination Complexes / Q000138:chemical synthesis*; D018360:Crystallography, X-Ray; D006885:Hydroxybutyrates / Q000737:chemistry; D008697:Methane / Q000031:analogs & derivatives / Q000737:chemistry; D008968:Molecular Conformation; D010165:Palladium / Q000737:chemistry; D010422:Pentanones / Q000737:chemistry
chemical_list: D056831:Coordination Complexes; D006885:Hydroxybutyrates; D010422:Pentanones; C049529:acetyl acetonate; C030011:carbene; D010165:Palladium; D008697:Methane
keywords: Suzuki-Miyaura cross coupling; abnormal carbenes; click chemistry; mesoionic carbenes; palladium; triazolylidenes