Polymer-supported carbene complexes of palladium: well-defined, air-stable, recyclable catalysts for the Heck reaction
N-Heterocyclic dicarbene chelate complexes of formula [cis-CH2N(H)C=C(H)N(R)C2PdX2] (X = Br, I; R = (CH2)nOH; n = 2, 3) have been prepared and structurally characterized (for X= I, n = 2). The complexes were immobilized on a functionalized polystyrene support (Wang resin) through one of the oxygen centres. The complexes efficiently catalyze the Heck reaction of activated and non-activated arylbromides, are recyclable under aerobic conditions and exhibit hardly any leaching, which is in line with our theoretical investigations on ligand dissociation energies related to Pd0 and PdII centres.
Schwarz
J
Anorganisch-Chemisches Institut, Technische Universitat Munchen, Garching, Germany. lit@arthur.anorg.chemie.tu-muenchen.de
Bohm
VP
Gardiner
MG
Grosche
M
Herrmann
WA
Hieringer
W
Raudaschl-Sieber
G