Synthesis of the first imidazolyl-triphosphines containing a Triphos unit

Andrieu, Jacques; Azouri, Michèle

doi:10.1016/j.ica.2006.07.056

Cited by 19 publications

(19 citation statements)

References 24 publications

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“…[10] Thus, after addition of 3d to an equimolar amount of Ni(CO) 4 in a toluene/CH 2 Cl 2 solution, the related n CO (A 1 ) stretching wave number was observed at 2087 cm À1 in the infrared spectrum. This higher value categorizes 3d as being much less electron-donating than the common aryl tertiary phosphines [n CO (A 1 ) = 2069 cm À1 with PPh 3 ] and more precisely in the range of the tris-halogenophosphines, or of the weaker electron-donating phosphites like PA C H T U N G T R E N N U N G (OPh) 3 (2085 cm…”

Section: Resultsmentioning

confidence: 93%

“…The electron donor properties of the phosphorus atom of a tertiary phosphine are easily evaluated by infrared measurement of the A 1 symmetric stretching frequency detected in the corresponding nickel carbonyl complex prepared in situ by phosphine substitution of a CO group in [Ni(CO) 4 ]. Although less toxic compounds than Ni(CO) 4 (prepared in situ from [NiA C H T U N G T R E N N U N G (COD) 2 ]) are now more commonly used (such as [Rh(CO) 2 Cl] 2 ), we opted to prepare the nickel carbonyl adduct in order to compare easily the parameters of the new imidazolium-2-phosphane complexes directly with the large database tabulated by Tolman [12] and with our other nickel tricarbonyl phosphenium complexes [Ni(CO) 3 …”

Section: Resultsmentioning

confidence: 99%

“…Although less toxic compounds than Ni(CO) 4 (prepared in situ from [NiA C H T U N G T R E N N U N G (COD) 2 ]) are now more commonly used (such as [Rh(CO) 2 Cl] 2 ), we opted to prepare the nickel carbonyl adduct in order to compare easily the parameters of the new imidazolium-2-phosphane complexes directly with the large database tabulated by Tolman [12] and with our other nickel tricarbonyl phosphenium complexes [Ni(CO) 3 …”

Section: Resultsmentioning

confidence: 99%

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Donor‐Stabilized Phosphenium Adducts as New Efficient and Immobilizing Ligands in Palladium‐Catalyzed Alkynylation and Platinum‐Catalyzed Hydrogenation in Ionic Liquids

et al. 2009

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Abstract:The straightforward synthesis of a new donor-stabilized phosphenium ligand 3d by addition of bromodifurylphosphine to 1,3-dimethylimidazolium-2-carboxylate 1 is described. The obtained ligand exhibits a very strong p-acceptor character, comparable to that of triphenyl phosphite [PA C H T U N G T R E N N U N G (OPh) 3 ] or of tris-halogenophosphines, with a n CO (A 1 ) at 2087 cm À1for its nickel tricarbonyl complex. This ligand, as well as the related 3a which was obtained from chloroA C H T U N G T R E N N U N G diphenylphosphine, were tested in palladiumcatalyzed aryl alkynylation and in the platinum-catalyzed selective hydrogenation of chloronitrobenzenes, both in an ionic liquid phase. In C À C bond cross-coupling we observed that the increase of the p-acceptor character in ligand 3d, due to the introduction of an additional electron-withdrawing group, provides a very efficient catalyst in the alkynylation reaction of aryl bromides with phenylacetylene, including the deactivated 4-bromoanisole or the sterically hindered 2-bromonaphthalene. The catalytic activity decreases with recycling due to the sensitiveness of ligands to protonation in the ionic phase.Conversely, a multiple recycling of the metal/ligand system in non-acidic media was achieved from platinum-catalyzed hydrogenation of m-chloronitrobenzene. The catalytic results obtained by employing the complex of platiA C H T U N G T R E N N U N G num(II) chloride with 3a [transPtCl 2 (3a) 2 ] in comparison with the non-ionic related trans-tris(triphenylphosphine)platinum dichloride [trans-PtCl 2 A C H T U N G T R E N N U N G (PPh 3 ) 2 ] complex clearly indicate that the simultaneous existence of a strong p-acceptor character and a positive charge within the ligand 3a significantly increases the life-time of the platinum catalyst. The selectivity of the reaction is also improved by decreasing the undesirable formation of dehalogenation products. This cationic platinum complex trans-PtCl 2 (3a) 2 is the first example of a highly selective catalyst for hydrogenation of chloronitroarenes immobilized in an ionic liquid phase. The system was recycled six times without noticeable metal leaching in the organic phase, and no loss of activity.

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Section: Resultsmentioning

confidence: 93%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Donor‐Stabilized Phosphenium Adducts as New Efficient and Immobilizing Ligands in Palladium‐Catalyzed Alkynylation and Platinum‐Catalyzed Hydrogenation in Ionic Liquids

et al. 2009

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“…However, when the conditions described for the preparation of Triphosline [23] were applied to this vinyl difurylphosphine 1 in the presence of phenylphosphine and AIBN, several signals were observed in the corresponding spectrum (Fig 1). The signals which appeared as a doublet and a triplet at -59 and at -17 ppm with a typical [22,23] 3 J PP coupling constant of 32 Hz were assigned to the expected 2 ] 2b and b', with an expected 2b: 2b' ratio equal to one, see Fig. (1).…”

Section: A Synthesis Of Triphosfurane Ligandmentioning

confidence: 98%

“…They are also susceptible to functionalization by a dangling imidazolium (or imidazolidinium) ionic fragment to enhance their anchoring capacity into highly polar media. [22,23] In several cases, the replacement of triphenylphosphine ligands by trifurylphosphine has led to enhanced activity in metal catalysis. For instance, better performances were found in palladium-catalysed aryl alkynylation, in platinumcatalysed hydrogenation of chloronitrobenzene, [19] for Negishi cross-coupling, [24] and for rhodium catalyzed reactions.…”

Section: Introductionmentioning

confidence: 99%

Linear Triphosphines as Ligands for Metal Complexes Immobilization in Ionic Liquids: Palladium-Catalyzed Methoxylation of Alkynes

Harmand¹,

Saleh²,

Andrieu

et al. 2012

TOOCJ

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4 ] mixture. We discovered that the addition of an ionic liquid to methanol allowed not only to increase the activity of the palladium catalyst but also to provide a recyclable catalyst which can be reused several times with a weaker drop of activity. To complete these catalytic studies, we describe the synthesis of the first poor -electron-donating/strong -electron-acceptor linear Triphosphine which, after palladium coordination, led to a better selectivity compared to its Triphos analogue. The performances of recovered ionic liquid reaction mixtures show for the first time that P-tridentate ligands efficiently immobilize palladium catalysts and lead to selective catalytic systems benign for environment.

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The Design of Ligand Systems for Immobilisation in Novel Reaction Media

Webb

Hamilton

2012

Phosphorus(III) Ligands in Homogeneous Catalysis: Design and Synthesis

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Synthesis of the first imidazolyl-triphosphines containing a Triphos unit

Cited by 19 publications

References 24 publications

Donor‐Stabilized Phosphenium Adducts as New Efficient and Immobilizing Ligands in Palladium‐Catalyzed Alkynylation and Platinum‐Catalyzed Hydrogenation in Ionic Liquids

Donor‐Stabilized Phosphenium Adducts as New Efficient and Immobilizing Ligands in Palladium‐Catalyzed Alkynylation and Platinum‐Catalyzed Hydrogenation in Ionic Liquids

Linear Triphosphines as Ligands for Metal Complexes Immobilization in Ionic Liquids: Palladium-Catalyzed Methoxylation of Alkynes

The Design of Ligand Systems for Immobilisation in Novel Reaction Media

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