Xavier Morise

Cyclopropanation and Diels–Alder reactions catalyzed by the first heterobimetallic complexes with bridging phosphinooxazoline ligands

The bimetallic complex trans-[(OC)3Fe(μ-LP,N)2Cu]BF4 (2), which contains two bridging phosphinooxazoline ligands, is the first metal–metal bonded six-membered ring system with P,N donors and its crystal structure shows a unique bimetallic cradle conformation. This complex is an efficient catalyst for the cyclopropanation of styrene by ethyl diazoacetate and for the Diels–Alder reaction between cyclopentadiene and methacrolein, these reactions being catalyzed for the first time by heterometallic complexes.

Comparison in halide binding ability between the unsaturated clusters [Pd3(μ-dppm)3(CO)]2+ and [PdPtCo(μ-dppm)2(CO)3(CNtBu)]+ (dppm = Ph2PCH2PPh2)

The trinuclear clusters [Pd3(μ-dppm)3(CO)]2+ and [PtPdCo(μ-dppm)2(CO)3(CNtBu)]+ exhibit a large and a small cavity, respectively, formed by the phenyl rings of the bridging diphosphine ligands. Their binding constants (K11) with halide ions (X−) were obtained by UV-Vis spectroscopy. The binding ability varies as I− > Br− > Cl−, and [Pd3(μ-dppm)3(CO)]2+ ⪢> [ptPdCo(μ-dppm)2-(CO)3(CNtBu)]+. The MO diagram for the related cluster [Pd2Co(μ-dppm)2(CO)4]+ has been addressed theoretically in order to predict the nature of the lowest energy electronic bands. For this class of compounds, the lowest energy bands are assigned to charge transfers from the Co center to the Pd2 centers.

Monocyclopentadienyl complexes of niobium, tantalum and tungsten containing heterodifunctional P,O ligandsDedicated to Prof. P. Royo on the occasion of his 65th birthday, with our warmest congratulations.

The reactions of P,O type ligands with the half-sandwich complexes [(η-C5R5)MCl4] (R5 = H5, Me5, iPrH4; M = Nb, Ta, W) have been investigated. Monodentate P-adducts were obtained with the β-amidophosphine Ph2PCH2C(O)NPh2, whereas in the case of the keto ligand Ph2PCH2C(O)Ph a spontaneous HCl elimination occurred to give direct access to the corresponding phosphinoenolate complexes. The crystal structures of [(η-C5H5)NbCl3{PPh2CHC(O)Ph}], [(η-C5H5)TaCl3{PPh2CHC(O)Ph}] and [(η-C5Me5)TaCl3{PPh2CHC(O)Ph}] have been determined. Interestingly, the acetamido derived phosphine Ph2PNHC(O)Me afforded O-adducts, which is an unusual bonding mode for a P,O ligand.

Phosphinooxazolines as assembling ligands in heterometallic complexes

It is shown that phosphinooxazolines such as (2-oxazoline-2-ylmethyl)diphenylphosphine 1 can be used as P,N assembling ligands for the synthesis of heterometallic complexes. These were obtained in a stepwise manner from the iron carbonyl complexes containing one, [Fe(CO)4(PCH2-oxazoline-P)] 2, or two, trans-[Fe(CO)3(PCH2-oxazoline-P)2] 6, P-bound phosphinooxazoline ligands. These metalloligands were then reacted with metal complexes. With 2, complete ligand transfer from Fe to the second metal (Pd) was sometimes observed. The metal–metal bonded complex [(OC)4Fe(μ-PCH2-oxazoline-P,N)PdCl2] 3 was of limited stability, whereas the trinuclear complex trans-[{(OC)4Fe(μ-PCH2-oxazoline-P,N)}2CoCl2] 4, in which 2 functions as a N-donor metalloligand toward the tetrahedral Co(II) centre, was stable and could be fully characterised by X-ray diffraction. This complex catalyses the oligomerization of ethylene to give linear α-olefins in the range C4–C26, with a maximum of the Schulz-Flory distribution around C6. The complex [{(OC)4Fe(μ-PCH2-oxazoline-P,N)}2HgI2] 5 was also prepared from 6. With the metalloligand 6, the Fe→Pd and Fe→Co metal–metal bonded compounds trans-[(OC)3Fe(μ-PCH2-oxazoline-P,N)2Pd(NCMe)](BF4)28 and trans-[(OC)3Fe(μ-PCH2-oxazoline-P,N)2CoCl2] 9 were obtained.

Carbonyl clusters with a capping methylidyne phosphonate ligand crystal structure of [CO3(CO)9{η1-μ3-[CP(O) (OEt)2]}]

The bridging methylidyne clusters [Co 3 (CO) 9 { η 1 - μ 3 -[CP(O)(OR) 2 ])] 1 (R = Et) and 3 (R = SiMe 3 ) with α -phosphoryl substituents have been synthesized by reaction of Cl 3 C-P(O)(OR) 2 with Co 2 (CO) 8 , followed by protonation. Cluster 3 was also obtained by the reaction of 1 with Me 3 SiBr. The structure of 1 has been determined by X-ray crystallography. The donor properties of the P=O function toward Lewis acids such as [Cp 2 MCl] + (M = Ti, Zr) were used to assemble early—late metal systems.

New palladium complexes with phosphino- and phosphinitopyridine ligands.

Three new palladium complexes containing a difunctional P,N-chelate, namely tris(chloro{[1-methyl-1-(6-methyl-2-pyridyl)ethoxy]diphenylphospine-kappa(2)N,P}methylpalladium(II)chloroform solvate, 3[Pd(CH(3))Cl(C(21)H(22)NOP)].CHCl(3), (III), dichloro[2-(2,6-dimethylphenyl)-6-(diphenylphosphinomethyl)pyridine-kappa(2)N,P]palladium(II), [PdCl(2)(C(26)H(24)NP)], (IV), and chloro[2-(2,6-dimethylphenyl)-6-(diphenylphosphinomethyl)pyridine-kappa(2)N,P]methylpalladium(II), [Pd(CH(3))Cl(C(26)H(24)NP)], (V), are reported. Geometric data and the conformations of the ligands around the metal centers, as well as slight distortions of the Pd coordination environments from idealized square-planar geometry, are discussed and compared with the situations in related compounds. Non-conventional hydrogen-bond interactions (C-H...Cl) have been found in all three complexes. Compound (III) is the first six-membered chloro-methyl-phosphinite P,N-type Pd(II) complex to be structurally characterized.

η-Cyclopentadienyltungsten compounds with vinyl- and allyl-phosphine ligands

The properties as ligands of the primary phosphines PH2(CHCH2)1 and PH2(CH2CHCH2)2 have been studied. The new compounds [W(η-C5R5)Cl4(PH2R′)](R5= H4Pri, R′= CHCH27 or CH2CHCH28; R5= Me4Et, R′= CHCH29 or CH2CHCH210), [W2(η-C5H4Pri)2X4(µ-H)(µ-PHR)](X = Cl, R = CHCH212 or CH2CHCH213; X = Br, R = CHCH215), [W2(η-C5Me5)2Cl4(µ-H)(µ-PHC2H3)]17 and [W2(η-C5Me5)2Cl2(µ-Cl)(µ-PHC2H3)]18 have been prepared. The crystal structures of compounds 10 and 17 have been determined.

Synthesis and crystal structure of [PdMe{PPh2NHC(O)Me}{O=C(NH2)Me}][BF4], a palladium complex containing the acetamide ligand

Abstract The synthesis of a square planar cationic Pd(II) complex containing the acetamide ligand is described. The complex has been characterised by X-ray diffraction, leading to one of the rare examples of a crystal structure showing an acetamide molecule coordinated to a metal centre and, to the best of our knowledge, the first one with palladium. This complex may be relevant to catalytic reactions, such as the palladium-catalysed amidocarbonylation, in which transient species with O-coordinated acetamide can be formed.

Reductive carbonylations reactions of primary phosphine mono-η-cyclopentadienyltungsten (V) compounds☆

Abstract The new tungsten (IV) compounds [W(η-C5H4iPr)(Cl3(P)(CO)] (where P = H2PC3H5, H2PC3H5, H2PC2H3 or PMe3) have been prepared from the corresponding tungsten (V)_compounds [W((η-C5H4iPr)Cl4(P)] by treatment with [Fe2(CO)9] The crystal structures have been determined for the W(IV) compounds with P = H2PC2H5 and PMe3. a a

Metal assisted deprotonation of a β-phosphonato-phosphine ligand. X-ray structure of Pd(II) complexes with new P,O donor ligands

Abstract The new diethyl-{(diphenylphosphino)phenyl}methylphosphonate ligand, rac-Ph2PCH(Ph)P(O)(OEt)2 1, has been prepared and coordinated to a Pd(II) metal centre to form P,O chelates involving P(III) and P(V) centres, as established by X-ray diffraction of cis-[Pd{Ph2PCH(Ph)P(O)(OEt)2-κ2-P,O }2](BF4)2 2. Deprotonation of P-bound 1 led to the first anionic β-phosphonato-phosphine P,O chelate, which was characterised by X-ray diffraction in complex [(dmba)Pd{Ph2PC(Ph)PO(OEt)2-κ2-P,O }] 4. To cite this article: X. Morise et al., C.R. Chimie 6 (2003) 000–000.