TY  - JOUR
A1  - Schmidt, Bernd
A1  - Geissler, Diana
T1  - Ru- and Pd-Catalysed Synthesis of 2-Arylfurans by One-Flask Heck Arylation/Oxidation
JF  - European journal of organic chemistry
N2  - 2,5-Disubstituted furans were synthesized by one-flask Heck arylation/oxidation sequences. The starting materials are 2-substituted 2,3-dihydrofurans, conveniently available by RCM/isomerization sequences, and arenediazonium salts. These react in ligand-free Heck reactions to afford 2,5-disub-stituted 2,5-dihydrofurans, which are oxidized to the corresponding furans without isolation or intermediate workup. The oxidation is conveniently achieved with chloranil or DDQ, depending on the substrate.
KW  - Diazonium salts
KW  - Palladium
KW  - C-C coupling
KW  - Heck coupling
KW  - Furans
KW  - Oxidation
KW  - Oxygen heterocycles
Y1  - 2011
U6  - https://doi.org/10.1002/ejoc.201100549
SN  - 1434-193X
IS  - 25
SP  - 4814
EP  - 4822
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  - Baier, Heiko
A1  - Kelling, Alexandra
A1  - Schilde, Uwe
A1  - Holdt, Hans-Jürgen
T1  - Investigation of the Catalytic Activity of a 2-Phenylidenepyridine Palladium(II) Complex Bearing 4,5-Dicyano-1,3-bis(mesityl)imidazol-2-ylidene in the Mizoroki-Heck Reaction
JF  - Zeitschrift für anorganische und allgemeine Chemie
N2  - The phenylidenepyridine (ppy) palladacycles [PdCl(ppy)(IMes)] (4) [IMes = 1,3-bis(mesityl) imidazol-2-ylidene] and [PdCl(ppy){(CN)(2)IMes}] (6) [(CN)(2)IMes = 4,5-dicyano-1,3-bis(mesityl) imidazol-2-ylidene] were prepared by facile two step syntheses, starting with the reaction of palladium(II) chloride with 2-phenylpyridine followed by subsequent addition of the NHC ligand to the precatalyst precursor [PdCl(ppy)](2). Suitable crystals for the X-ray analysis of the complexes 4 and 6 were obtained. It was shown that 6 has a shorter NHC-palladium bond than the IMes complex 4. The difference of the palladium carbene bond lengths based on the higher pi-acceptor strength of (CN)(2)IMes in comparison to IMes. Thus, (CN)(2)IMes should stabilize the catalytically active central palladium atom better than IMes. As a measure for the pi-acceptor strength of (CN)(2)IMes compared to IMes, the selone (CN)(2)IMes center dot Se (7) was prepared and characterized by Se-77-NMR spectroscopy. The pi-acceptor strength of 7 was illuminated by the shift of its Se-77-NMR signal. The Se-77-NMR signal of 7 was shifted to much higher frequencies than the Se-77-NMR signal of IMes center dot Se. Catalytic experiments using the Mizoroki-Heck reaction of aryl chlorides with n-butyl acrylate showed that 6 is the superior performer in comparison to 4. Using complex 6, an extensive substrate screening of 26 different aryl bromides with n-butyl acrylate was performed. Complex 6 is a suitable precatalyst for para-substituted aryl bromides. The catalytically active species was identified by mercury poisoning experiments to be palladium nanoparticles.
KW  - Carbene ligands
KW  - Heck reaction
KW  - Palladium
KW  - Selenium
KW  - C-C coupling
Y1  - 2016
U6  - https://doi.org/10.1002/zaac.201500625
SN  - 0044-2313
SN  - 1521-3749
VL  - 642
SP  - 140
EP  - 147
PB  - Wiley-VCH
CY  - Weinheim
ER  -