Polystyrene-supported dicyclohexylphenylphosphine adducts of amine- and phosphite-based palladacycles in the Suzuki coupling of aryl chlorides

Abstract

The polystyrene-immobilised palladacyclic complexes [Pd(TFA)(κ²-N,C-C₆H₄CH₂NMe₂){P(C₆H₄-4-PS)Cy₂}] and [PdCl(κ²-P,C-{P(OC₆H₂-2,4-^tBu₂)(OC₆H₃-2,4-^tBu₂)₂}{P(C₆H₄-4-PS)Cy₂}] (PS = polystyrene) and the homogeneous analogues [Pd(TFA)(κ²-N,C-C₆H₄CH₂NMe₂)(PPhCy₂)] and PdCl(κ²-P,C-{P(OC₆H₂-2,4-^tBu₂)(OC₆H₃-2,4-^tBu₂)₂}(PPhCy₂)] were synthesised and characterised. The X-ray structure of one of the homogeneous analogues, [Pd(TFA)(κ²-N,C-C₆H₄CH₂NMe₂)(PPhCy₂)] was determined. All the complexes have been tested and show good activity in the Suzuki coupling of aryl chloride substrates. While the polystyrene-immobilised complexes are not recyclable, they are easily extracted and show low levels of palladium leaching.