TY  - JOUR
A1  - Baier, Heiko
A1  - Kelling, Alexandra
A1  - Holdt, Hans-Jürgen
T1  - PEPPSI-Effect on Suzuki-Miyaura Reactions Using 4,5-Dicyano-1,3-dimesitylimidazol-2-ylidene-Palladium Complexes: A Comparison between trans-Ligands
JF  - European journal of inorganic chemistry : a journal of ChemPubSoc Europe
N2  - The PEPPSI (Pyridine Enhanced Precatalyst Preparation, Stabilization and Initiation) complexes 12-15 with the structure [PdCl2{(CN)(2)IMes}(3-R-py)] (12: R = H; 13: R = Cl; 14: R = Br; 15: R = CN) bearing the maleonitrile-based N-heterocyclic carbene (NHC) (CN)(2)IMes ({(CN)(2)IMes}: 4,5-dicyano-1,3-dimesitylimidazol-2-ylidene) were prepared. Solid state structures of 14 and 15 were obtained. Complexes 14 and 15 adopt a slightly distorted square-planar coordination geometry in the solid state with the substituted pyridine ligand trans to the NHC. Catalytic activities of precatalysts 12-15 were studied and subsequently compared to complexes [PdCl2{(CN)(2)IMes}(PPh3)] (4) and [PdCl(dmba){(CN)(2)IMes}] (5) recently reported by our group in the Suzuki-Miyaura reaction of various aryl halides and phenylboronic acid. Reactions using previously reported [PdCl2(IMes)(py)] (IMes: 1,3-dimesitylimidazol-2-ylidene) (1) were also carried out and their results contrasted to those involving 12-15, 4 and 5. Differences in initiation rates and the catalytically active species related to the seven complexes in regards to the throw away ligand were investigated. Poisoning experiments with mercury show that palladium nanoparticles are responsible for the catalytic activity.
KW  - Carbene ligands
KW  - Palladium
KW  - Cross-coupling
KW  - Arenes
Y1  - 2015
U6  - https://doi.org/10.1002/ejic.201500010
SN  - 1434-1948
SN  - 1099-0682
IS  - 11
SP  - 1950
EP  - 1957
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Schmidt, Bernd
A1  - Elizarov, Nelli
A1  - Riemer, Nastja
A1  - Hölter, Frank
T1  - Acetamidoarenediazonium Salts: Opportunities for Multiple Arene Functionalization
JF  - European journal of organic chemistry
N2  - Unlike their ortho counterparts, meta- and para-acetamidoanilines can be converted into the corresponding acetamidoarenediazonium salts. These offer various opportunities for multiple Pd-catalyzed arene functionalization reactions, such as Matsuda-Heck-, Suzuki-Miyaura- or Fujiwara-Moritani couplings.
KW  - Arenes
KW  - Amides
KW  - C-C coupling
KW  - Cross-coupling
KW  - Palladium
Y1  - 2015
U6  - https://doi.org/10.1002/ejoc.201500795
SN  - 1434-193X
SN  - 1099-0690
IS  - 26
SP  - 5826
EP  - 5841
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Schmidt, Bernd
A1  - Riemer, Martin
T1  - Synthesis of Magnaldehydes B and E and Dictyobiphenyl B by Microwave-Promoted Cross-Coupling of Boronophenols
JF  - European journal of organic chemistry
N2  - Magnaldehydes B and E along with their 4'-methylated derivatives are naturally occurring 2,4'-biphenols that have been isolated from the Magnoliaceae. Herein, these natural products have been synthesized from a common intermediate, which was obtained by a microwave-promoted, hetero-geneously catalyzed, and protecting-group-free Suzuki-Miyaura coupling reaction in an aqueous medium. These reaction conditions were also successfully applied to a one-step synthesis of the slime mold metabolite dictyobiphenyl B.
KW  - Total synthesis
KW  - Natural products
KW  - Cross-coupling
KW  - Palladium
KW  - Biaryls
KW  - Phenols
Y1  - 2015
U6  - https://doi.org/10.1002/ejoc.201500350
SN  - 1434-193X
SN  - 1099-0690
IS  - 17
SP  - 3760
EP  - 3766
PB  - Wiley-VCH
CY  - Weinheim
ER  -