Intermediates in the Palladium-Catalyzed Reaction of 1,3-Dienes, Part 6 [1]

Abstract

The structure of the (1,3-butadiene)M(R₂PC₂H₄PR₂) compounds (M = Ni, Pd, Pt; R = Prⁱ, Bu′, Cy) in the solid-state have been investigated by ¹³C and ³¹P CP/MAS NMR spectroscopy. The bonding mode adopted by the diene is dependent upon the nature of the metal: the palladium compounds contain an η²-diene molecule, the nickel compound where R is cyclohexyl contains an η⁴-diene molecule whereas the Pr₂ ⁱPC₂H₄PPr₂ ⁱ-stabilized platinum compound con- tains a platinacyclopentene ring. The crystal structures of (η²-1,3-C₄H₆)Pd(Cy₂PC₂H₄PCy₂) and (η⁴-1,3-C₄H₆)Ni(Cy₂PC₂H₄PCy₂) have been confirmed by X-ray diffraction.