New P,N ligands with chiral nitrogen center: applications in homogeneous catalysis

Saluzzo, Christine; Breuzard, Jérémy A.J; Pellet‐Rostaing, Stéphane; Vallet, Martial; Guyader, Frédéric Le; Lemaire, Marc

doi:10.1016/s0022-328x(01)01148-2

Cited by 41 publications

(21 citation statements)

References 45 publications

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“…1 H NMR spectroscopy shows both complexes to be paramagnetic, which indicates a tetrahedral arrangment around the nickel atom. Evans' NMR-based method [39] was used for measuring the magnetic susceptibility of compounds 9 and 10, and it was found that both compounds have an S = 2 ground state, in agreement with the presence of tetrahedral complexes with a 3d 8 -electron configuration. The magnetic moments were determined to be μ eff = 3.0 μ B for compound 9 and μ eff = 2.8 μ B for compound 10. www.zaac.wiley-vch.de 695…”

Section: Scheme 5 Syntheses Of Palladium(ii) Complexes [(Dmiqci)pdclmentioning

confidence: 94%

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Quinine‐Derived Imidazolidin‐2‐imine Ligands: Synthesis, Coordination Chemistry, and Application in Catalytic Transfer Hydrogenation

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Hrib

Randoll

et al. 2010

Zeitschrift anorg allge chemie

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Section: Scheme 5 Syntheses Of Palladium(ii) Complexes [(Dmiqci)pdclmentioning

confidence: 94%

“…These 1,2-diamines were previously used as ligands in iridium-and ruthenium-catalyzed asymmetric transfer hydrogenation of ketones [6,7]. Other P,N- [8] and O,N-ligands [9] based on the quincorine and quin- coridine framework and their coordination chemistry and applications in homogeneous catalysis have been described. Scheme 1.…”

Section: Introductionmentioning

confidence: 99%

Quinine‐Derived Imidazolidin‐2‐imine Ligands: Synthesis, Coordination Chemistry, and Application in Catalytic Transfer Hydrogenation

Filimon

Hrib

Randoll

et al. 2010

Zeitschrift anorg allge chemie

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“…A hemilabile behavior for related chiral P,N ligands could explain the low enantioselectivities observed in asymmetric Rh-catalyzed hydroformylation. [22,23] On the other hand, an optically pure Ru II β-amino-phosphane complex led to higher ee for the asymmetric reduction of ketones, whereas a related Ru-γ-amino-phosphane complex led to the same product in racemic form. [6] We now wish to provide new information on the effect of a dangling vs. a coordinated nitrogen function of chiral P,N ligands in rhodium hydroformylation catalysis, thus helping to clarify a few previously obscure points.…”

Section: Introductionmentioning

confidence: 99%

Amino‐phosphanes in Rh^I‐Catalyzed Hydroformylation: Hemilabile Behavior of P,N Ligands under High CO Pressure and Catalytic Properties

et al. 2005

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The catalytic properties of rhodium complexes containing the α‐, β‐, or γ‐amino‐phosphane ligands Ph2PCH2NEt2 (α‐P,N‐1), Ph2PCH(Ar)NHPh [α‐P,N‐2; Ar = η6(o‐C6H4Cl)Cr(CO)3], Ph2PCH2NPh2 (α‐P,N‐3), Ph2PCH2CH(Ph)NHPh (β‐P,N), Ph2PCH2(o‐C6H4–NMe2) (γ‐P,N‐1), Ph2PCH(o‐C6H4–CH2NHPh) (γ‐P,N‐2), and the α,β‐diamino‐phosphane ligand Et2NCH2P(Ph)CH2CH(Ph)NHPh (α,β‐N,P,N), in styrene hydroformylation have been examined. The results show that the activity increases when the number of backbone carbon atoms linking P and N decreases from 3 to 1. IR and 31P HPNMR studies in solution show that all P,N ligands adopt exclusively a κ1‐P coordination mode in rhodium chloride carbonyl complexes under high CO pressure. In the solid state a κ1‐P‐α‐amino‐phosphane coordination has been ascertained by X‐ray methods in trans‐[RhCl(CO)(γ‐P,N‐1)2]. In contrast, an equilibrium between the κ2‐P,N and κ1‐P‐coordination modes has been observed as a function of the CO pressure for the complex containing the β‐P,N ligand. The basicity of the dangling amino group also plays an important role on the catalytic activity and a mechanism involving the nitrogen function in the catalytic cycle is proposed.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)

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“…In this interaction, the Rh center acts as a Lewis acid, accepting H -, whereas the nearby amine function acts as a Lewis base, capturing the proton. Nevertheless, even in the presence of chiral α-, [17] β-P,N [12] or other P,N ligands, [19,20] the enantioselectivity of branched aldehydes formed in styrene hydroformylation were very low (Ͻ14 %). We decided to further investigate the mechanistic details of the enantioselective process by additional experiments based on H/D isotopic exchanges using D 2 O as a deuterium source.…”

Section: Introductionmentioning

confidence: 99%

Amino‐phosphanes in Rh^I‐Catalyzed Hydroformylation: New Mechanistic Insights Using D₂O as Deuterium‐Labeling Agent

et al. 2005

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Keywords: Rhodium / Amino-phosphane ligands / H/D isotopic exchange / Hydroformylation catalysis / EnantioselectivityIn previous work, we have demonstrated that the dangling amino group in amino-phosphane ligands increases the rate of Rh-catalyzed styrene hydroformylation as a function of the amino group basicity and of the distance between the P and N functions. We now report additional stereochemical and mechanistic insights resulting from new catalytic experiments performed with Rh-α-P,N catalytic systems in the presence of D 2 O. In addition to the expected D 0 product, the formation of the β-D 1 aldehyde, PhCH(CH 2 D)CHO was observed in all cases by 1 H and 13 C NMR spectroscopy, indicating that H/D exchange occurs for the rhodium-hydride complex. Minor amounts of a β-D 2 product, PhCH(CHD 2 )CHO, were also formed under certain conditions, demonstrating the reversibility of the olefin coordination step. The composition of the aldehyde mixture is slightly affected by the nature of the catalytic precursor or the P,N ligand used. In the specific case of the α-P,N ligand [α-P,N = (S Ar ,S C )-Ph 2 PCH-

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New P,N ligands with chiral nitrogen center: applications in homogeneous catalysis

Cited by 41 publications

References 45 publications

Quinine‐Derived Imidazolidin‐2‐imine Ligands: Synthesis, Coordination Chemistry, and Application in Catalytic Transfer Hydrogenation

Quinine‐Derived Imidazolidin‐2‐imine Ligands: Synthesis, Coordination Chemistry, and Application in Catalytic Transfer Hydrogenation

Amino‐phosphanes in Rh^I‐Catalyzed Hydroformylation: Hemilabile Behavior of P,N Ligands under High CO Pressure and Catalytic Properties

Amino‐phosphanes in Rh^I‐Catalyzed Hydroformylation: New Mechanistic Insights Using D₂O as Deuterium‐Labeling Agent

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New P,N ligands with chiral nitrogen center: applications in homogeneous catalysis

Cited by 41 publications

References 45 publications

Quinine‐Derived Imidazolidin‐2‐imine Ligands: Synthesis, Coordination Chemistry, and Application in Catalytic Transfer Hydrogenation

Quinine‐Derived Imidazolidin‐2‐imine Ligands: Synthesis, Coordination Chemistry, and Application in Catalytic Transfer Hydrogenation

Amino‐phosphanes in RhI‐Catalyzed Hydroformylation: Hemilabile Behavior of P,N Ligands under High CO Pressure and Catalytic Properties

Amino‐phosphanes in RhI‐Catalyzed Hydroformylation: New Mechanistic Insights Using D2O as Deuterium‐Labeling Agent

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Product

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Amino‐phosphanes in Rh^I‐Catalyzed Hydroformylation: Hemilabile Behavior of P,N Ligands under High CO Pressure and Catalytic Properties

Amino‐phosphanes in Rh^I‐Catalyzed Hydroformylation: New Mechanistic Insights Using D₂O as Deuterium‐Labeling Agent