In this study, 5,11,17,23-tetra-tert-butyl-25,26,27,28-tetrakis(2-diphenylphosphinoxy-ethoxy) calixarene (5) and 5,11,17,23-tetra-tert-butyl-25,26,27,28-tetrakis(2-diphenylphosphinoethoxy)- calixarene (6), as well as their platinum and palladium complexes (PtCl2)2(5), (PdCl2)2(5) were synthesised and characterised. In addition to these transition metal-containing complexes the catalytic systems formed in situ, from catalytic precursors PtCl2(PhCN)2, [Rh(nbd)Cl]2 and PdCl2(PhCN)2 and the corresponding calixarene ligand, were tested as catalysts in hydroformylation and hydrocarbalkoxylation, respectively. High chemoselectivity was obtained in hydroformylation in the presence of rhodium-containing catalysts both with the above calixarene-based phosphine and phosphinite ligands. The regioselectivity towards branched aldehyde shows a strong temperature dependence in case of phosphinite derivative. Although the platinum-containing systems show much lower catalytic activity, the regioselectivities are undoubtedly higher than those obtained with PtCl2(diphosphine)-SnCl2 systems.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Organic Chemistry
- Inorganic Chemistry
- Materials Chemistry