TY - JOUR
T1 - Active anionic zero-valent palladium catalysts
T2 - Characterization by density functional calculations
AU - Kozuch, Sebastian
AU - Shaik, Sason
AU - Jutand, Anny
AU - Amatore, Christian
PY - 2004/6/21
Y1 - 2004/6/21
N2 - This works uses DFT (B3LYP/LACVP*+//B3LYP/LACVP* level) to ascertain the existence of the tricoordinate, anionic zero-valent palladium complexes that were postulated as the active species in the catalytic cycles of Pd-catalyzed Heck and cross-coupling reactions. The variety of complexes studied (1 and 2), include [Pd(PR3)2X] - species, in which R=H, Me, vinyl, and phenyl, and X=Cl, Br, I, AcO, and TFA, as well as bidentate complexes, [Pd{Ph2P(CH 2)nPh2P}X]-, in which X = Cl, AcO and n = 3-6. The study shows that these complexes exist as distinct minima in the gas phase as well as in THF. In addition, it provides geometric features and Pd-X- dissociation energies for all these complexes as well as some NMR and IR data, which show a clear distinction in these features between the tri- and dicoordinate Pd0 species. An orbital interaction model and perturbation theory arguments account for the bonding mechanism and rationalize all the trends in the stability of the Pd-X bond. These trends include the effects of variation of X, R, and the length of the linker in the bidentate ligands.
AB - This works uses DFT (B3LYP/LACVP*+//B3LYP/LACVP* level) to ascertain the existence of the tricoordinate, anionic zero-valent palladium complexes that were postulated as the active species in the catalytic cycles of Pd-catalyzed Heck and cross-coupling reactions. The variety of complexes studied (1 and 2), include [Pd(PR3)2X] - species, in which R=H, Me, vinyl, and phenyl, and X=Cl, Br, I, AcO, and TFA, as well as bidentate complexes, [Pd{Ph2P(CH 2)nPh2P}X]-, in which X = Cl, AcO and n = 3-6. The study shows that these complexes exist as distinct minima in the gas phase as well as in THF. In addition, it provides geometric features and Pd-X- dissociation energies for all these complexes as well as some NMR and IR data, which show a clear distinction in these features between the tri- and dicoordinate Pd0 species. An orbital interaction model and perturbation theory arguments account for the bonding mechanism and rationalize all the trends in the stability of the Pd-X bond. These trends include the effects of variation of X, R, and the length of the linker in the bidentate ligands.
KW - Cross-coupling
KW - Density functional calculations
KW - Heck reaction
KW - Ligand effects
KW - Palladium
UR - http://www.scopus.com/inward/record.url?scp=3042825014&partnerID=8YFLogxK
U2 - 10.1002/chem.200306056
DO - 10.1002/chem.200306056
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AN - SCOPUS:3042825014
SN - 0947-6539
VL - 10
SP - 3072
EP - 3080
JO - Chemistry - A European Journal
JF - Chemistry - A European Journal
IS - 12
ER -