Organocatalysed Asymmetric Oxidation Reactions

Buckley, Benjamin R.; Neary, Stephen P.

doi:10.1007/978-90-481-3865-4_1

Cited by 3 publications

(2 citation statements)

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“…Due to the applications in intermediates and precursors for the synthesis of perfumes, drugs, and epoxy paints, epoxides are known as a kind of valuable building block in organic synthesis . Therefore, the catalytic epoxidation of olefins to epoxides constitutes a promising research area .…”

Section: Introductionmentioning

confidence: 99%

Kinetic Studies and Reaction Network in the Epoxidation of Styrene Catalyzed by the Temperature-Controlled Phase-Transfer Catalyst [(C₁₈H₃₇)₂(CH₃)₂N]₇[PW₁₁O₃₉]

Chen

Wang

et al. 2022

Ind. Eng. Chem. Res.

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The olefin epoxidation reaction is of great interest in recent years since epoxide is considered an important intermediate for a wide application range. H2O2-based catalytic epoxidation possesses the advantages of being cheap, green, and safe, which are quite advantageous in chemical technology. A phase-transfer catalyst, especially the phosphotungstate catalyst, has been applied in the epoxidation reaction with a high reaction rate and moderate reaction conditions. In this work, a phase-transfer catalyst, [(C18H37)2(CH3)2N]7[PW11O39], has been synthesized, and it showed high catalytic efficiency in styrene epoxidation. The influence of reaction time, temperature, oxidant concentration and amount, catalyst amount, and substrate concentration on the reaction performance was studied. A styrene conversion of 90.1% and selectivity of 90.6% could be achieved at 85 °C for 1 h with 3 equiv of H2O2 and 1.5 mol % catalyst. More importantly, kinetic models for the reaction network have been studied to optimize the reaction conditions and limit the side reactions.

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Section: Introductionmentioning

confidence: 99%

Kinetic Studies and Reaction Network in the Epoxidation of Styrene Catalyzed by the Temperature-Controlled Phase-Transfer Catalyst [(C₁₈H₃₇)₂(CH₃)₂N]₇[PW₁₁O₃₉]

Chen

Wang

et al. 2022

Ind. Eng. Chem. Res.

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“…The synthesis and use of enantiopure sulfoxides is a topic of extraordinary interest in asymmetric synthesis, asymmetric catalysis and in the pharmaceutical industry [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 ]. The enantioselective sulfoxidation of prochiral sulfides is one of the most challenging approaches to chiral sulfoxides, and catalyzed processes based on metal complexes [ 3 , 4 , 10 , 11 , 12 , 13 , 14 , 15 , 16 ] and metal-free systems [ 17 ] have been described in the literature. Molybdenum-catalyzed enantioselective sulfoxidations have been investigated [ 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 ] and, in general, the Mo catalysts provided results that are somewhat lower than those of other metals, as for example titanium [ 26 , 27 , 28 , 29 , 30 , 31 , 32 ] or vanadium [ 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 ] complexes.…”

Section: Introductionmentioning

confidence: 99%

Molybdenum-Catalyzed Enantioselective Sulfoxidation Controlled by a Nonclassical Hydrogen Bond between Coordinated Chiral Imidazolium-Based Dicarboxylate and Peroxido Ligands

2018

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Chiral alkyl aryl sulfoxides were obtained by molybdenum-catalyzed oxidation of alkyl aryl sulfides with hydrogen peroxide as oxidant in mild conditions with high yields and moderate enantioselectivities. The asymmetry is generated by the use of imidazolium-based dicarboxylic compounds, HLR. The in-situ-generated catalyst, a mixture of aqueous [Mo(O)(O2)2(H2O)n] with HLR as chirality inductors, in the presence of [PPh4]Br, was identified as the anionic binuclear complex [PPh4]{[Mo(O)(O2)2(H2O)]2(μ-LR)}, according to spectroscopic data and Density Functional Theory (DFT) calculations. A nonclassical hydrogen bond between one C–H bond of the alkyl R group of coordinated (LR)− and one oxygen atom of the peroxido ligand was identified as the interaction responsible for the asymmetry in the process. Additionally, the step that governs the enantioselectivity was theoretically analyzed by locating the transition states of the oxido-transfer to PhMeS of model complexes [Mo(O)(O2)2(H2O)(κ1-O-LR)]− (R = H, iPr). The ∆∆G≠ is ca. 0 kcal∙mol−1 for R = H, racemic sulfoxide, meanwhile for chiral species the ∆∆G≠ of ca. 2 kcal∙mol−1 favors the formation of (R)-sulfoxide.

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Efficient organocatalytic synthesis of styrene oxide from styrene and its kinetic study in a continuous-flow microreaction system

Chen

Wang

et al. 2022

Chemical Engineering Science

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Organocatalysed Asymmetric Oxidation Reactions

Cited by 3 publications

References 143 publications

Kinetic Studies and Reaction Network in the Epoxidation of Styrene Catalyzed by the Temperature-Controlled Phase-Transfer Catalyst [(C₁₈H₃₇)₂(CH₃)₂N]₇[PW₁₁O₃₉]

Kinetic Studies and Reaction Network in the Epoxidation of Styrene Catalyzed by the Temperature-Controlled Phase-Transfer Catalyst [(C₁₈H₃₇)₂(CH₃)₂N]₇[PW₁₁O₃₉]

Molybdenum-Catalyzed Enantioselective Sulfoxidation Controlled by a Nonclassical Hydrogen Bond between Coordinated Chiral Imidazolium-Based Dicarboxylate and Peroxido Ligands

Efficient organocatalytic synthesis of styrene oxide from styrene and its kinetic study in a continuous-flow microreaction system

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Organocatalysed Asymmetric Oxidation Reactions

Cited by 3 publications

References 143 publications

Kinetic Studies and Reaction Network in the Epoxidation of Styrene Catalyzed by the Temperature-Controlled Phase-Transfer Catalyst [(C18H37)2(CH3)2N]7[PW11O39]

Kinetic Studies and Reaction Network in the Epoxidation of Styrene Catalyzed by the Temperature-Controlled Phase-Transfer Catalyst [(C18H37)2(CH3)2N]7[PW11O39]

Molybdenum-Catalyzed Enantioselective Sulfoxidation Controlled by a Nonclassical Hydrogen Bond between Coordinated Chiral Imidazolium-Based Dicarboxylate and Peroxido Ligands

Efficient organocatalytic synthesis of styrene oxide from styrene and its kinetic study in a continuous-flow microreaction system

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Kinetic Studies and Reaction Network in the Epoxidation of Styrene Catalyzed by the Temperature-Controlled Phase-Transfer Catalyst [(C₁₈H₃₇)₂(CH₃)₂N]₇[PW₁₁O₃₉]

Kinetic Studies and Reaction Network in the Epoxidation of Styrene Catalyzed by the Temperature-Controlled Phase-Transfer Catalyst [(C₁₈H₃₇)₂(CH₃)₂N]₇[PW₁₁O₃₉]