Recent advances and perspectives in the manganese-catalysed epoxidation reactions

Mesoporous silica has been functionalized with 3‐aminopropyl triethoxy silane (3‐APTES), followed by Schiff‐base condensation with 2‐hydroxy‐1‐naphthaldehyde. Incorporation of copper and nickel by covalent grafting onto the Schiff‐base loaded materials gives two heterogenized catalysts namely, Cu–Cat and Ni‐Cat, respectively. The materials have been characterized by PXRD analyses, nitrogen sorption studies, TEM, TGA, FT‐IR, UV‐visible and solid state MAS‐NMR spectroscopy. The metal‐contents in the samples are estimated using ICP‐AES studies. Cu–Cat and Ni‐Cat have been used as active catalyst in the oxidation of various olefins e. g. styrene, α‐methyl styrene, cyclohexene, trans stilbene and cyclooctene in the presence of tert‐butyl hydroperoxide as the oxidant in acetonitrile under mild conditions. Different products have been analyzed by gas chromatography and gas chromatography‐mass spectrometry. The results show high conversion of the substrates, moderate to good product selectivity and high TOFs of the reactions. The catalysts are recycled without deteriorating their activities and heterogeneous nature.

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“…Mo, Ru,, Pd, Fe, Mn, Cu, Ni, etc . incorporated materials have been used as catalysts in C−H activation of alkenes.…”

Section: Introductionmentioning

confidence: 94%

Cu- and Ni-Grafted Functionalized Mesoporous Silica as Active Catalyst for Olefin Oxidation

et al. 2017

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“…In 1990, a pivotal discovery was illustrated by the groups of Jacobsen [72] and Katsuki [73], who independently reported the asymmetric epoxidation of a variety of unfunctionalized alkenes with optically pure Mn(III)/salen complexes using readily available PhIO, bleach, H 2 O 2 , oxone as the terminal oxidants, providing good levels of enantioselectivity [74]. Soon after their discovery, enantioselective epoxidations catalyzed by Jacobsen-Katsuki complexes were employed as key steps in the synthesis of biologically active products, such as anti-HIV compound indinavir (crixivan ® ) [75], and Iks-channel blockers (Scheme 37) [76].…”

Section: Asymmetric Metal-catalyzed Epoxidations As Key Stepsmentioning

confidence: 99%

Applications of Chiral Three-membered Rings for Total Synthesis: A Review

Dalpozzo¹,

Lattanzi

Pellissier

2017

COC

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This review updates recent applications of asymmetric aziridination, azirination, thiirination, epoxidation, and cyclopropanation in the total synthesis of biologically active compounds, including natural products, using chiral substrates or chiral catalysts, covering the literature since 2000. The interest towards these synthetic methodologies of chiral three-membered rings has increased in the last decade, dictated either by the biological activities that display many naturally occurring products bearing a three-membered unit or by the ring strain of three-membered rings making them useful precursors of many more complex interesting molecules. Classic as well as modern protocols in asymmetric aziridinations, azirinations, epoxidations, thiirinations, and cyclopropanations have been widely applied as key steps of a number of syntheses of important products. Although the use of chiral substrates and auxiliaries is still highly employed particularly in asymmetric aziridination and cyclopropanation, the development of enantioselective catalytic methodologies has witnessed exponential growth during the last decade. The present review is subdivided into three parts, dealing successively with the use of chiral nitrogen-containing three-membered rings, chiral epoxides and thiiranes, and chiral cyclopropanes in total synthesis.

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“…168 Mn-and Fecatalyzed asymmetric epoxidations are similar in terms of the ligands employed, the substrate scope, and the reaction mechanism. The use of hydrogen peroxide as oxidant in Mn-catalyzed epoxidation was reviewed recently by Krishnan et al 169 Being similar to iron, the manganese-porphyrin complexes were found to be able to catalyze the asymmetric epoxidation of unfunctionalized olefins with aqueous hydrogen peroxide as oxidant but the substrate scope was relatively narrow and the level of the asymmetric induction was only moderate. 170 In 2011, Bryliakov et al discovered that a Mn complex with a tetradentate aminopyridine ligand featuring a cyclohexanediamine scaffold was an efficient catalyst for the enantioselective epoxidation of olefins using aqueous hydrogen peroxide as the terminal oxidant and a large excess amount of acetic acid as additive, although the products were obtained in lower enantioselectivities.…”

Section: Epoxidationmentioning

confidence: 99%

Synthetic utility of metal catalyzed hydrogen peroxide oxidation of C-H, C-C and C=C bonds in alkanes, arenes and alkenes: Recent advances

Wójtowicz‐Młochowska¹

2016

Arkivoc

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This review presents the current state of the art of homogenic and heterogenic oxygen transfer processes using hydrogen peroxide as oxygen source and compounds and complexes of tranisition metals, Fe, V, Cu, Mn, Rh, Mo, Ti, W, Pd, Os, Zr, Cr, Nb, Co, as the catalysts. Based on the reactions of C-H, C-C and C=C bonds in alkanes, arenes and alkenes various mechanisms of the oxygen-transfer processes are discussed and new methodologies for synthesis of alcohols, phenols, aldehydes, ketones, epoxides and carboxylic acids are indicated.

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Recent advances and perspectives in the manganese-catalysed epoxidation reactions

Cited by 58 publications

References 134 publications

Cu- and Ni-Grafted Functionalized Mesoporous Silica as Active Catalyst for Olefin Oxidation

Cu- and Ni-Grafted Functionalized Mesoporous Silica as Active Catalyst for Olefin Oxidation

Applications of Chiral Three-membered Rings for Total Synthesis: A Review

Synthetic utility of metal catalyzed hydrogen peroxide oxidation of C-H, C-C and C=C bonds in alkanes, arenes and alkenes: Recent advances

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