New (η<sup>3</sup>-Allyl)palladium Complexes with Pyridylpyrazole Ligands: Synthesis, Characterization, and Study of the Influence of N1 Substituents on the Apparent Allyl Rotation
作者:Vanessa Montoya、Josefina Pons、Jordi García-Antón、Xavier Solans、Mercè Font-Bardía、Josep Ros
DOI:10.1021/om070093u
日期:2007.6.1
The allylpalladium [Pd(eta(3)-C3H5)(L)](BF4) (L = L-1 (1), L-2 (2), L-3 (3), L-4 (4)) complexes with pyridylpyrazole ligands 2-(5-phenyl-1H-pyrazol-3-yl)pyridine (L-1), 2-(1-ethyl-5-phenyl-1H-pyrazol-3-yl)pyridine (L-2), 2-(1-octyl-5-phenyl)-1H-pyrazol-3-yl)pyridine (L-3), and 2-(5-phenyl-3-(pyridin-2-yl)pyrazol-1-yl)ethanol (L-4) were synthesized from the appropriate pyridylpyrazole ligand and [Pd(eta(3)-C3H5)Cl](2) in the presence of AgBF4. The cationic complex 1 was converted into the neutral complex 5 under basic conditions. These complexes were characterized, and the crystal and molecular structure of [Pd(eta(3)-C3H5)(L-2)](BF4) (2) was resolved by X-ray diffraction. Also, we have studied the apparent allyl rotation, observed as H-syn-H-syn and H-anti-H-anti interconversions. The influences of the solvent, the traces of water, and the N1 substituent have also been studied.