Palladium coordination compounds of σ3λ5-phosphoranes: First examples of phosphonio-methylene(imino)metallophosphorane [(R3P)(Me3Si)C=P(MLn)=NSiMe3] and phosphonio-methylene(oxo)phosphorane [(R3P)(Me3Si)C=P(=O)NSiMe3] ligands

Wayde V. Konze, Victor G. Young, Robert J. Angelici

Research output: Contribution to journalArticlepeer-review

7 Scopus citations

Abstract

The oxidative addition reaction of Pd(PPh3)4 with Cl2C=PN(SiMe3)2 forms the phosphavinyl phosphonium complex Cl(Ph3P)Pd[η2-C(Cl)(PPh3)=PN(SiMe 3)2] (IIIa), which results from PPh3 migration from Pd to carbon in the η1-phosphavinyl intermediate trans-Cl(Ph3P)2Pd-[C(Cl)=PN(SiMe3)2] (IIa). The reaction of Pd(dba)(dppe) with Cl2C=PN(SiMe3)2 forms the η1-phosphavinyl complex cis-Cl(dppe)Pd[C(Cl)=PN(SiMe3)2] (VI), which does not undergo phosphine migration. Compound IIIa undergoes substitution of the chloride ligand by PPh3 or MeCN in the presence of KPF6 to generate [(Ph3P)2Pd(η2-C(Cl)(PPh 3)=PN(SiMe3)2)](PF6) (IV) or [(Ph3P)(MeCN)Pd(η2-C(Cl)(PPh3)=PN(SiMe 3)2)](PF6) (V), respectively; the structure of V was determined by X-ray diffraction studies. The reaction of Pd(PEt3)4 with Cl2C= PN(SiMe3)2 forms the η1-phosphavinyl complex trans-Cl(Et3P)2Pd[C(Cl)=PN(SiMe3)2] (IIb), which does not undergo PEt3 migration. When 2 equiv of Pd(PEt3)4 are reacted with Cl2C= PN(SiMe3)2 the phosphonio-methylene(imino)metallophosphorane complex Pd(PEt3)(Cl)[μ-η12-C(SiMe 3)(PEt3)=P=N(SiMe3)]Pd(PEt3)Cl (VIIa-b) forms as a 1:1 isomeric mixture. Compound VIIa-b reacts with MeI or NaI to generate Pd(PEt3)(I)[μ-η12-C(SiMe 3)(PEt3)= P=N(SiMe3)]Pd(PEt3)I (VIIIa-b) and reacts with traces of water to generate Cl(Et3P)Pd-[η2-C(SiMe3)(PEt 3)=P(=O)NH(SiMe3)] (IX). The structure of VIIIb was partially determined, and the structure of IX was determined by X-ray diffraction studies. Compounds VIIa-b, VIIIa-b, and IX exhibit the first examples of coordinated methylene(imino, oxo)phosphorane ligands.

Original languageEnglish (US)
Pages (from-to)5275-5286
Number of pages12
JournalOrganometallics
Volume17
Issue number24
DOIs
StatePublished - 1998

Fingerprint

Dive into the research topics of 'Palladium coordination compounds of σ<sup>3</sup>λ<sup>5</sup>-phosphoranes: First examples of phosphonio-methylene(imino)metallophosphorane [(R<sub>3</sub>P)(Me<sub>3</sub>Si)C=P(ML<sub>n</sub>)=NSiMe<sub>3</sub>] and phosphonio-methylene(oxo)phosphorane [(R<sub>3</sub>P)(Me<sub>3</sub>Si)C=P(=O)NSiMe<sub>3</sub>] ligands'. Together they form a unique fingerprint.

Cite this