Heterogeneous asymmetric hydrogenation over chiral molecule-modified metal particles

Zhan, Ensheng; Chen, Chuansheng; Li, Yong; Shen, Wenjie

doi:10.1039/c4cy00900b

Cited by 34 publications

(22 citation statements)

References 108 publications

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“…Their addition in small amounts to the liquid reaction solution can lead to strong stereochemical control in heterogeneous hydrogenations on Pt and Pd catalysts. [11][12][13][14][15][16] Despite the practical simplicity, the enantioselectivity-controlling process at the catalytic solidliquid interface, that is, the influence of the surface coverage and molecular orientation of the chiral modifier on the catalytic performance are still rather poorly understood, which impedes the development of chirally-modified metals for heterogeneous asymmetric catalysis. 3 Quantum chemical calculations have become a powerful tool to investigate and predict the behavior of complex chemical systems, e.g.…”

Section: Introductionmentioning

confidence: 99%

The Critical Role of Tilted Cinchona Surface Species for Enantioselective Hydrogenation

et al. 2017

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On chirally-modified metal catalysts enantioselectivity is controlled by the molecular orientation of adsorbates at the chiral catalytic solid-liquid interface. To gain information on the surface coverage and to assess the enantioselecting ability of chiral modifiers depending on their molecular orientation we employed an operando spectroscopic technique using attenuated total reflection-IR and UV-Vis spectroscopies. Our study reveals that the enantiodifferentiation of the cinchona chiral modifier cinchonine varies significantly depending on its adsorption mode. In contrast to the prevailing mechanistic models, which imply that the most stable surface species is responsible for enantiodifferentiation, our results show that less stable cinchona species with a tilted aromatic ring anchor provide significantly stronger enantioselective control. As a consequence the so-called anchoring moiety of the chiral modifier exceeds the mere function of adsorptive anchoring and its molecular orientation has to be also taken into account in explaining the observed enantioselectivity of chirally-modified metals.

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Section: Introductionmentioning

confidence: 99%

The Critical Role of Tilted Cinchona Surface Species for Enantioselective Hydrogenation

et al. 2017

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“…34 This system, ie, Raney Ni asymmetrized by tartaric acid, and other variants of it, have since been studied extensively specifically by local probe techniques such as scanning tunneling microscopy. [35][36][37][38][39] Many groups across the world have taken on these systems to elucidate the exact mechanisms of what happens at the interface between the chiral modifier and the catalysts' surface, and a relatively large body of literature is available [40][41][42][43][44][45][46][47] for the interested reader.…”

Section: Heterogeneous Asymmet-ric Catalystsmentioning

confidence: 99%

Spectroscopy for model heterogeneous asymmetric catalysis

Kartouzian¹

2019

Chirality

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Heterogeneous catalysis has vastly benefited from investigations performed on model systems under well‐controlled conditions. The application of most of the techniques utilized for such studies is not feasible for asymmetric reactions as enantiomers possess identical physical and chemical properties unless while interacting with polarized light and other chiral entities. A thorough investigation of a heterogeneous asymmetric catalytic process should include probing the catalyst prior to, during, and after the reaction as well as the analysis of reaction products to evaluate the achieved enantiomeric excess. I present recent studies that demonstrate the strength of chiroptical spectroscopic methods to tackle the challenges in investigating model heterogeneous asymmetric catalysis covering all the abovementioned aspects.

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“…First, in 2004, our group developed a catalytic system based on HEA16Cl‐capped Pt(0) nanoparticles, modified by cinchonidine, a well‐known chiral inducer in heterogeneous asymmetric catalysis 92. This catalyst was successfully used in the pure biphasic liquid‐liquid asymmetric hydrogenation of ethylpyruvate over several runs, with a constant e.e .…”

Section: Metal Nps In Aqueous Media: Relevant Tools For Polyphasic Camentioning

confidence: 99%

Odyssey in Polyphasic Catalysis by Metal Nanoparticles

Denicourt‐Nowicki

Roucoux

2016

The Chemical Record

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Nanometer-sized metal particles constitute an unavoidable family of catalysts, combining the advantages of molecular complexes in regards to their catalytic performances and the ones of heterogeneous systems in terms of easy recycling. As part of this research, our group aims at designing well-defined metal nanoparticles based-catalysts, in non-conventional media (ionic liquids or water), for various catalytic applications (hydrogenation, dehalogenation, carbon-carbon coupling, asymmetric catalysis) in mild reaction conditions. In the drive towards a more eco-responsible chemistry, the main focuses rely on the search of highly active and selective nanocatalysts, in association with an efficient recycling mainly under pure biphasic liquid-liquid conditions. In this Personal Account, we proposed our almost fifteen-years odyssey in the world of metal nanoparticles for a sustainable catalysis.

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Heterogeneous asymmetric hydrogenation over chiral molecule-modified metal particles

Cited by 34 publications

References 108 publications

The Critical Role of Tilted Cinchona Surface Species for Enantioselective Hydrogenation

The Critical Role of Tilted Cinchona Surface Species for Enantioselective Hydrogenation

Spectroscopy for model heterogeneous asymmetric catalysis

Odyssey in Polyphasic Catalysis by Metal Nanoparticles

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