586344-96-9Relevant academic research and scientific papers
Synthesis of C1-symmetric tripod ligands containing a P,P,N donor set -η2-coordination in d8-metal complexes
Faissner, Ralf,Huttner, Gottfried,Kaifer, Elisabeth,Rutsch, Peter
, p. 1681 - 1693 (2007/10/03)
Tripod ligands RC(CH2X)(CH2Y)(CH2Z) (X, Y, Z = NR2, PR2) are accessible from α,β-unsaturated esters R(=CH2)COOR′. The key steps in this synthetic approach are Michael additions of amines and phosphanes to produce RCH(COOR′)(CH2X) (X = NR2, PR2) (2 and 3), followed by hydroxymethylation with paraformaldehyde to result in RC(COOR′)(CH2OH)(CH2X) (X = NR2) (4). Standard transformations of this C1-symmetric precursor allow for the synthesis of tripod ligands such as PhC(CH2pz)(CH2PPh2)(CH2PMes) (11). Coordination of these ligands with d8-metal ions [nickel(II), palladium(II), rhodium(I)] results in square-planar complexes with the chelate cycles in half-chair, twist-boat or boat conformations, depending on the specific substitution pattern. Coordination through two phosphane donors with the nitrogen donor acting as a dangling arm is generally preferred throughout. Detail preparative procedures and complete characterisation by analytical methods, including X-ray analysis of the coordination compounds, are given. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.
