New, efficient, heterogenized catalysts for asymmetric hydrogenation of dehydroamino acid derivatives

Zsigmond, Ágnes; Balatoni, Istvan; Notheisz, Ferenc; Hegedűs, Csaba; Bakos, József

doi:10.1007/s10562-005-4891-5

Cited by 12 publications

(12 citation statements)

References 13 publications

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“…With the final goal of developing active and enantioselective heterogeneous catalysts, anchored [Rh(NBD) (2S,4S)-BDPP] + PF6 _ and [Rh(NBD)(2S,4S)-3,5-diMe-BD PP] + PF 6 _ catalysts were prepared [68] with the method developed by Augustine and co-workers [20,21,65].…”

Section: Hydrogenation On [Rh(nbd)(2s4s)-bdpp] + Pf 6 _ Complexesmentioning

confidence: 99%

Selective Syntheses on Heterogenized Metal Complexes

Zsigmond

Notheisz

2006

COC

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The preparation and application of heterogenized metal complexes is a relatively new field of research resulting in a new way of catalysis, that we cannot realize either with traditional homogeneous or heterogeneous catalysts. The heterogenized metal complexes can successfully combine the excellent performance (high activity and selectivity) of homogeneous catalysts with the easy separation and recycling of the heterogeneous catalysts. Additionally, in several cases the immobilization of metal complexes leads to enhanced stereo-, chemo-and enantioselectivity, interpreted by a mechanism related to the "confinement concept". This review gives a summary of the different ways of preparation of heterogenized metal complexes on inorganic matrices and shows some applications of such catalysts in synthetic organic chemistry. a) Direct Attachment to the SupportThis can be performed in several different ways: by simple adsorption, ion-pair formation or using an anchoring agent. The easy preparation of these systems is a clear advantage, but their sensitivity to solvent effects is an important drawback.Charges were created on silica via reaction with a silylating agent containing a SO 3 --group. The positively charged Rh(I)-complexes were then ion-exchanged and used in hydrogenations. Leaching could be avoided in toluene and water, but not in methanol [17]. LDHs were used to retain a sulfonated BINAP complex bearing 4 negative charges via

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Section: Hydrogenation On [Rh(nbd)(2s4s)-bdpp] + Pf 6 _ Complexesmentioning

confidence: 99%

Selective Syntheses on Heterogenized Metal Complexes

Zsigmond

Notheisz

2006

COC

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“…The examples about the use of these solids as supports of chiral catalysts are scarce. Pioneering work by Augustine et al [11][12][13] described the immobilization of Rh-diphosphine complexes on different alumina-supported heteropolyanions and their use in hydrogenation reactions, with improved activity and enantioselectivity [14,15], mainly upon recycling. Ru-Binap [16] and Rh-prolinamide [17] complexes were also immobilized by the same procedure.…”

Section: Introductionmentioning

confidence: 99%

Supported heteropolyanions as solid counterions for the electrostatic immobilization of chiral copper complexes

Torviso

Blanco

Cáceres

et al. 2010

Journal of Catalysis

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Supported (PW 12 O 40 3−) is a suitable counterion to immobilize chiral azabis(oxazoline)copper complexes through electrostatic interactions (ion pair formation). Catalytic results are good to excellent in cyclopropanation reactions (up to 97% ee). Partial leaching during recycling when mono-exchanged species are present, favored by strong coordination of by-products, can be minimized by a proper solvent choice and by optimization of the recycling system, allowing the recovery and reuse of the catalyst at least six times without loss of activity and enantioselectivities in the range of 82-96% ee for trans cyclopropanes.

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“…The anchoring of the complex was done in two steps, by a method developed by Augustine et al [13,14,16]. 1.5 g of Al 2 O 3 was suspended in 30 mL of methanol.…”

Section: Catalystsmentioning

confidence: 99%

“…The performance of the immobilized complexes were compared to the performance of the homogeneous analogues and usually the heterogenized complexes had higher activity and selectivity. Further, the easy handling and the recyclability make them favourable as compared to their homogeneous counterpart [15,16].…”

Section: Introductionmentioning

confidence: 99%

Comparative Study of Immobilized Phthalocyanines in Oxidative Degradation

Bata

Demjén

Notheisz

et al. 2012

TOCATJ

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Immobilized iron phthalocyanine catalysts were prepared, via two heterogenization methods: anchoring by Augustine's method and the preparation of a "ship-in-a-bottle" type catalyst by intrazeolite synthesis method. The heterogenized catalysts were applied in the oxidative destruction of 4-chlorophenol, as a common pollutant of waste water. The performance of the two heterogenized and the homogeneous complexes were compared and it was found that the immobilized complexes had about the same activity as the homogeneous analog. Both heterogenized samples could be recycled in three subsequent runs and the "ship-in-a-bottle" type showed stable activity. Meanwhile, the anchored complex lost some activity in every subsequent run. Consequently, the first catalyst was better for practical application.

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New, efficient, heterogenized catalysts for asymmetric hydrogenation of dehydroamino acid derivatives

Cited by 12 publications

References 13 publications

Selective Syntheses on Heterogenized Metal Complexes

Selective Syntheses on Heterogenized Metal Complexes

Supported heteropolyanions as solid counterions for the electrostatic immobilization of chiral copper complexes

Comparative Study of Immobilized Phthalocyanines in Oxidative Degradation

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