219909-46-3Relevant academic research and scientific papers
Formation of palladium- and platinum-substituted fulvenes by activation of a cyclopentadienyl or indenyl ligand
Alías, Francisco M.,Belderraín, Tomás R.,Paneque, Margarita,Poveda, Manuel L.,Carmona, Ernesto,Valerga, Pedro
, p. 5620 - 5629 (1998)
The stepwise, low-temperature reaction of {Pd[CH(SiMe3)2](/≤-Cl)(PMe3)}2 (1) with CNBu-t and NaCp′ (Cp′ = C5H5, C5H4Me) or Lilnd (Ind = C9H7) affords metal-substituted fulvenes of composition Pd[C(NHBu-t)=C(C4H3R)][CH(SiMe3) 2](CNBu-t)(PMe3) (R = H, Me) and Pd[C(NHBu-t)=C(C8H6)][CH(SiMe3) 2](CNBu-t)(PMe3), of which the C5H4Me-derived complex 5a has been characterized by X-ray crystallography. The mononuclear species Pd[CH(SiMe3)2]Cl(CNBu-t)(PMe3) (2) has been isolated as an intermediate of this reaction. An alternative synthesis of the palladabenzofulvene complex 6 involves the reaction of the 16 electron indenyl derivative (η3-Ind)Pd[CH(SiMe3)2](PMe3) (7) with 2 equiv of CNBu-t In this case an η1-ndenyl intermediate of composition (η1-Ind)Pd[CH(SiMe3)2](CNBu-t)(PMe 3) (8) can be observed by low-temperature NMR spectroscopy. The complex Pt[CH(SiMe3)2]Cl(CNBu-t)(PMe3) (12) has been synthesized by the comproportionation reaction of Pt[CH(SiMe3)2]Cl(PMe3)2 (10) and Pt[CH(SiMe3)2]Cl(CNBu-t)2 (11), in the presence of catalytic amounts of CNBu-t. Complex 12 reacts with CNBu-t and NaCp to give first the cationic species {Pt[CH(SiMe3)2](CNBu-t)2(PMe3)}Cl (13) and then a mixture of platinafulvene isomers related to the above-mentioned Pd complexes. The fluxionality of these metallafulvene derivatives and the mechanism of their formation are discussed.
