New insoluble surfactant systems as aids in catalysis. A convenient method for nonbonded immobilization of catalytically active transition metal complexes

Flach, H. N.; Grassert, Ingrid; Oehme, G.; Čapka, M.

doi:10.1007/bf00665643

Cited by 29 publications

(15 citation statements)

References 18 publications

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“…[150] Such macromolecular amphiphiles could be used in a membrane reactor. [151] Besides a series of dehydroamino acid derivatives, [152] the asymmetric hydrogenation of dehydrophosphonic acid esters [153] and dehydrophosphinic acid esters [154] could also be performed successfully.…”

Section: Reductionsmentioning

confidence: 99%

Reactions in Micellar Systems

2005

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The notion of "green chemistry" has encouraged even synthetic organic chemists to include water as a solvent. Incredible selectivities and activities can be achieved through the addition of amphiphiles with a defined structure. The morphology of supramolecular assemblies or associates formed by surfactants vary according to the temperature and concentration. As a rule, reactions are typically conducted using simple spherical aggregates, that is, micelles in the nanometer range. The strong polarity gradient present between the hydrophilic surface and the hydrophobic core of the micelle means that both nonpolar and polar reagents can be solubilized. This solubilization results in reactants becoming more concentrated within the micelle than in the surrounding water phase and leads to an acceleration of the reaction and causes selective effects. The kinetic treatment of reactions in micellar systems can be accomplished by considering them as microheterogeneous two-phase systems.

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Section: Reductionsmentioning

confidence: 99%

Reactions in Micellar Systems

2005

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“…Suitable carriers can be sulfonated Jacobsen's Mn-salen complex attached to polystyrene-PEG [40] and V-salen catalyst for cyanohydrin formation bound to silica [42]. Alternatives to the adsorption of the complex via interaction with the metal are the use of an appropriately functionalized (e.g., sulfonated) ligand [45], binding lipophilic ligands to surfaces functionalized (e.g., by surfactants) [46] or to surface-methylated silica [14]. A major advantage of this strategy is the possibility to use the unchanged ligands and complexes optimized for the homogeneous reaction.…”

Section: Heterogenization Via Adsorption and Ion Pair Formationmentioning

confidence: 99%

Enantioselective Reactions on Anchored Chiral Complexes

Blaser¹,

Pugin²

2008

Handbook of Heterogeneous Catalysis

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The sections in this article are Introduction Industrial Requirements Characteristics of the Manufacture of Enantiomerically Pure Products Process Development: Critical Factors for the Application of (Solid) Enantioselective Catalysts Requirements for Practically Useful Immobilized Catalysts A Preparation Methods B Supports C Catalysts D Catalytic Properties and Handling Anchoring Strategies and Support Materials Survey of Anchored Complexes Heterogenization via Covalently Bound Ligands Heterogenization via Adsorption and Ion Pair Formation Heterogenization via Entrapment Assessment and Conclusions

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“…The addition of both monomeric [17][18][19] and polymeric [19][20][21] surfactants significantly enhances the activity and the enantioselectivity. [22] The addition of micelleforming surfactants is necessary for this reaction, because an increase in the solubility of lipophilic substrates in water is required.…”

Section: Hydrogenationmentioning

confidence: 99%

“…The use of polymeric surfactants which form micelle-like structures could solve this problem. Regen [23] and Janout [24] have already utilized amphiphilic polymers in phase-transfer catalysis, and Flach et al [20,21] have synthesized new types of soluble and insoluble polysoaps for the use in asymmetric hydrogenation.…”

Section: Hydrogenationmentioning

confidence: 99%