New Approaches to Develop Recyclable Catalysts for the Synthesis of Chiral Epoxides

Kureshy, Rukhsana I.; Khan, Noor‐ul H.; Abdi, Sayed H. R.; Jasra, Raksh V.

doi:10.1002/chin.200728215

Cited by 1 publication

(2 citation statements)

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“…To solve this problem, heterogeneous catalysts have been developed by anchoring on polymeric supports [9] inorganic solids of various characteristics [10][11][12][13][14][15][16] ionic liquids [17,18] nanoparticles [19] or intercalation in clays [20]. Although in all these methodologies it has been possible to retain the catalyst in the solid matrix, some examples have been found in which this immobilization process results in a significant loss of activity, asymmetric induction capacity and selectivity due to unexpected changes in the stereoelectronic behavior of the catalyst [19].…”

Section: Introductionmentioning

confidence: 99%

“…An alternative strategy to the immobilization and that is inside the methods of heterogeneization, is the precipitation of homogeneous catalysts by manipulating their solubility in the reaction medium [20]. One way to manipulate the solubility is to increase the molecular weight of the catalyst, facilitating product isolation and catalyst recovery, which in turn aids post epoxidation [23].…”

Section: Introductionmentioning

confidence: 99%

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Enantioselective epoxidation of styrene using in-situ generated dimethyldioxirane and dimeric homochiral Mn(III)-Schiff base complex catalyst

Verdugo-Torres

Cubillos-Lobo

Rojas

2018

Rev.Fac.Ing.Univ.Antioquia

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The enantioselective epoxidation of styrene using in-situ generated dimethyldioxirane (DMD) and dimeric homochiral Mn(III)-Schiff base catalyst 1 has been explored. The parameters evaluated were olefin/oxidant molar ration, catalyst loading, reaction temperature and presence of nitrogen coordinating co-catalysts. Conversions of more than 99% and enantiomeric excess 66% were obtained. The selectivity is complete towards styrene oxide using 2 mol% catalyst loading, 1.36 mmol KHSO 5 in 8 ml of water, absence of co-catalyst and 17°C as reaction temperature. Furthermore, the catalyst could be recycled up to three times with slightly decrease of catalytic activity due mainly to the physical loss of the catalyst during the recovery step and at a lesser extent as a consequence of its oxidative degradation. RESUMEN: Se ha explorado la epoxidación enantioselectiva de estireno utilizando dimetildioxirano (DMD) generado in-situ y un complejo de base de Schiff homoquiral dimérico de Mn (III). Los parámetros evaluados fueron la relación molar olefina/oxidante, la cantidad de catalizador, la temperatura de reacción y la presencia de co-catalizadores coordinadores de nitrógeno. Se obtuvieron conversiones por encima de 99% y excesos enantioméricos cercanos al 66%. La reacción fue completamente selectiva hacia el óxido de estireno usando 2% en moles de carga de catalizador, 1.36 mmol de KHSO 5 en 8 ml de agua, ausencia de cocatalizador y 17ºC como temperatura de reacción. Además, el catalizador puede reutilizarse hasta tres veces con una leve disminución de la actividad catalítica debido principalmente, a la pérdida física del catalizador durante la etapa de recuperación del catalizador, y en menor medida a su degradación oxidativa.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Enantioselective epoxidation of styrene using in-situ generated dimethyldioxirane and dimeric homochiral Mn(III)-Schiff base complex catalyst

Verdugo-Torres

Cubillos-Lobo

Rojas

2018

Rev.Fac.Ing.Univ.Antioquia

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New Approaches to Develop Recyclable Catalysts for the Synthesis of Chiral Epoxides

Abstract: ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Cited by 1 publication

References 40 publications

Enantioselective epoxidation of styrene using in-situ generated dimethyldioxirane and dimeric homochiral Mn(III)-Schiff base complex catalyst

Enantioselective epoxidation of styrene using in-situ generated dimethyldioxirane and dimeric homochiral Mn(III)-Schiff base complex catalyst

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