177663-75-1Relevant academic research and scientific papers
Reactivity of diphenylphosphino enolato ligands in ruthenium(II) complexes and related processes involving easy cleavage of a phosphorus-carbon bond in functionalized phosphine ligands
Crochet, Pascale,Demerseman, Bernard,Rocaboy, Christian,Schleyer, Dana
, p. 3048 - 3061 (2008/10/08)
The migration of a phenyl group from phosphorus to the coordinated ruthenium center in complexes (η6-arene)[η2-Ph 2PC(R)=C(R′)O]RuCl, 2 [arene = 1,3,5-Me3C6H3 or C6Me6; R = H or Me; R′ = But], occurs in methanol at reflux. The reaction is favored by the addition of KOAc and affords selectively the stable phosphinito enolato derivatives (η6-arene)[η2-Ph-(MeO)PC(R)=C(R′)O]RuPh. In contrast, the reaction of complexes 2 with methanol and K2CO3 preserves the functional ligand and affords selectively the hydride derivatives (η6-arene)[η2-Ph 2PC(R)=C(R′)O]RuH. The cleavage of the ruthenium-chlorine bond in complexes 2 is also the preliminary step involved in the coupling process of functional phosphino enolato ligands with 1-alkynes HC=CR″. The reaction results in the formation of complexes {(η6-arene)Ru[η3-CH=C(R″)C(R)(PPh 2)C(R′)=O]}(PF6) [R = H or Me, R′ = But or Ph, R″ = H, Me, Ph, p-MeC6H4, or SiMe3], the isomerization of which into complexes {(η6-arene)Ru-[η3-CH(PPh 2)C(R″)=C(R)C(R′)=O]}(PF6), [R′ = But, R″ = H, Me, Ph, or p-MeC6H4] occurs only when R = H. The isomerization consists of an intramolecular [1,3]-migration of a phosphorus-carbon bond and is catalyzed by the fluoride anion. When R″ = H, a subsequent cleavage of the ruthenium-carbon bond foreshadows the formation of (η6-C6Me6)[η1-Ph 2-PCH2CH=CHC(=O)But]RuCl2, 11. Thus, starting from the precursor (η6-C6Me6)[η1-Ph 2-PCH2C(=O)But]RuCl2, the process achieves formally an insertion of ethyne into the starting functionalized phosphorus-carbon bond. The scarcely isolable complexes {(η6-arene)Ru-[η3-C(=CH2)C(R)(PPh 2)C(R′)=O]Ru}(PF6) [R = H or Me, R′ = But or Ph] reveal an easy cleavage of the functionalized phosphorus-carbon bond. This cleavage is the preliminary step involved in the formation of metallafuran complexes {(η6-arene)(Ph2PX)Ru[η2-C(CH 3)=CRC(R′)=O]}(PF6) [X = Cl or F, R = H or Me, R′ = But or Ph], which implies also the capture of a halide anion by phosphorus in a transient intermediate.
