First Allylpalladium Systems Containing Chiral Imidazolylpyridine Ligands – Structural Studies and Catalytic Behaviour

Abstract

Palladium/chiral imidazolylpyridine systems were tested in allylic alkylation of rac-3-acetoxy-1,3-diphenyl-1-propene (rac-I) and 3-acetoxy-1-phenyl-1-propene (II), paying particular attention to the influence of the amine nitrogen hybridisation on their catalytic behaviour. Allylpalladium complexes 9-11 containing optically pure imidazolines were synthesised and fully characterised both in solution (NMR) and the solid state (single-crystal X-ray diffraction). NMR studies

Dinuclear Allylpalladium Complexes ofC2-Symmetric Pyrazolate-Bridged Bis(oxazoline) Ligands (pyrbox's): Structures, Dynamic Behavior, and Application in Asymmetric Allylic Alkylation

“…Pd−C bond lengths in 4a , c are found as expected for palladium(II) allyl compounds, , and Pd−N bond lengths are common for pyrazolate- and oxazoline-derived ligands. A closer inspection of atom distances reveals that all Pd−N bond lengths are found in a rather narrow range (2.133(7)−2.098(9) Å), as are the Pd−CH 2 bonds (2.142(8)−2.098(9) Å).…”

Design of Cationic Mixed Phosphine/N-Heterocyclic Carbene Palladium(II) π-Allyl Complexes as Monoligated Phosphine Pd(0) Precatalysts: Synthesis, Structural Studies, Catalysis, and Reactivity

“…Palladium(II) π-allyl complexes have attracted considerable attention over the years, − mainly due to their reactivity toward nucleophiles, which makes those complexes excellent catalysts for the so-called Tsuji−Trost allylic alkylation. − Transition metal allyl complexes can exist in two coordination modes, η 1 (anionic, 2 e donor ligand) and η 3 (mixed, 4 e ligand). An interesting feature of Pd-allyl complexes is their tendency to undergo η 3 −η 1 −η 3 rearrangements (Scheme ):…”