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With the increasing demand for eco-friendly epoxides derived from vegetable oils, recent efforts have focused on developing methods for the epoxidation of sunflower oil. Sunflower oil, in particular, has emerged as a promising candidate for epoxidation due to its high content of unsaturated fatty acids, which provide abundant double bonds suitable for epoxide formation. In this study, epoxidized sunflower oil was produced using in situ formed peracid with a hybrid oxygen carrier combining formic acid and acetic acid. The optimal epoxidation reaction parameters were determined as follows: (1) a reaction temperature of 75 °C, (2) a catalyst loading of 0.9 g of hybrid oxygen carrier, (3) a stirring speed of 450 rpm, and (4) a hydrogen peroxide to sunflower oil molar ratio of 1.5. This research contributes to transforming sunflower oil into a value-added product, thereby reducing reliance on petroleum-based resources. [ABSTRACT FROM AUTHOR]

Recently, the trend of using renewable sources has great attention in the production of polyol chemicals via the epoxidation method. Palm-based polyols produced from the epoxidation and hydroxylation methods usually have low hydroxyl values (below 200 mg KOH/g). This study aimed to synthesize the hydroxylase polyols with a higher hydroxyl value from the renewable source palm oil. The epoxidized palm oleic acid was synthesized using the in situ performic acid, which is obtained from the reaction of formic acid and hydrogen peroxide. The Taguchi method was executed to optimize the epoxidation process for the maximum production of epoxidized oleic acid. Then, optimized epoxidized palm oleic acid was hydroxylated to produce polyols. In addition, the effect of process parameters on the polyol yields was also studied. At the optimum process parameters, the response of relative conversion to oxirane (RCO) with the determination of oxirane oxygen content (OOC) was found at the maximum value of 82%. According to the results, the maximum hydroxyl value produced was 339 mg KOH/g. A kinetic study revealed that the oxirane cleavage by methanol is a second-order reaction whereas the formation of epoxidized palm oleic acid is a first-order reaction. [ABSTRACT FROM AUTHOR]

• Epoxidation of compound A with m-CPBA produces P1 and P2 epoxides, modifying the C9=C10 double bond. • Computational DFT/B3LYP/6-31G(d) studies confirm the reaction's exothermic nature and high stereoselectivity, favoring P1 formation as seen in experiments. • IRC calculations indicate a straightforward, one-step epoxidation mechanism for compound A. • Evaluation of A, P1, and P2 includes molecular docking and dynamics to assess their potential as antidiabetic agents via alpha-amylase and alpha-glucosidase inhibition. Epoxidation of a β-himachalene derivative (A) can be carried out using meta -chloroperoxybenzoic acid (m-CPBA). An oxygen atom is added to the double bond C 9 C 10 , during the process, producing the epoxides P1 and P2. DFT calculations at the B3LYP/6-31G(d) level were used to study, Theoretically, the mechanism and stereoselectivity of the epoxidation reaction of compound A with m-CPBA. The calculation of activation energies associated with both possible reaction pathways, indicated that this epoxidation reaction is exothermic and highly stereoselective, favoring the formation of product P1 which is in agreement with the experimental results. Additionally, the IRC calculation shows that this reaction occurs via a one-step mechanism. The products P1, P2 , and the starting compound A were evaluated for their antidiabetic activity and their potential to inhibit alpha-amylase and alpha-glucosidase through molecular docking, molecular dynamics, and ADMET studies. The evaluation of these three compounds aimed to study the effect of epoxidation and stereoselectivity on their inhibitory activity against the two enzymes. [ABSTRACT FROM AUTHOR]

[Display omitted] • A breakthrough in the continuous epoxidation of vegetable oils. • The concept is based on two packed column reactors. • No added catalyst needed. • High epoxide selectivities achieved. • Safe operation conditions. Epoxidized Vegetable Oils (EVOs) are an important class of chemical compounds obtained from biomass and used as intermediates to produce several bio-products and chemicals, such as hydroxy-alkoxy compounds, diols, amines, and carbonates. Epoxides originating from vegetable oils and their derivatives, namely fatty acids or alkyl esters, are still produced by semibatch technology which suffers from severe mass transfer limitations and long reaction times, thus impairing the final product selectivity and restraining the overall productivity. In this work, two continuous reactor technologies to produce epoxides from vegetable oils were developed and compared. The first configuration, consisting of only one jacketed tubular reactor operated in co-current up-flow mode, showed a good performance at T = 318 K achieving a double bond conversion exceeding 95 % and an epoxide selectivity higher than 90 %. The second technology, where two jacketed tubular reactors connected in series were operated in up-flow mode, gave comparable conversions and selectivity to the previous one, but under somewhat milder conditions, at T = 294 K and 298 K for the first and second reactor, respectively, and in the absence of any added acid catalyst. Following this latter concept, additional experiments were performed in the presence of different vegetable oils as starting materials to confirm the performance with more common feedstocks. Both configurations showed results that clearly exceed the performance of the current semibatch process. [ABSTRACT FROM AUTHOR]

[Display omitted] • We developed a biocatalytic system for directly epoxidation of limonene to limonene dioxide. • A relatively high yield of 93 % for limonene dioxide achieved. • Cell wall and membrane lipases in Rhizopus oryzae drive slow percid production. • Optimal conditions include a high H 2 O 2 concentration and trisodium citrate addition. Limonene dioxide (LDO) is essential for manufacturing bio-based polycarbonate and non-isocyanate polyurethanes. Herein, we report a strategy for the chemoenzymatic epoxidation of (R)-(+)-limonene to LDO with high selectivity using Rhizopus oryzae whole cells. The presence of sufficient excess acid in the system is essential, in addition to overcoming the hydrolysis of the intermediate product, 1,2-limonene oxide, to accomplish the double epoxidation of limonene. When using a high concentration of H 2 O 2 and trisodium citrate, the conditions were effectively established, even when Novozym 435 was substituted, which had previously been reported to be ineffective in achieving high-yield double epoxidation of limonene. The transfer of H 2 O 2 and peracids between the cell and solvent slowed production. The total amount of peracids generated remained constant, but their concentrations remained moderate, favoring the double epoxidation of limonene. An LDO yield of 93 % and no intermediate product, limonene oxide, were obtained under optimized conditions within 20 h. [ABSTRACT FROM AUTHOR]

Solvent-free synthesis method in zeolite preparation can largely decrease the generation of wastewater and improve the zeolite yield by simply grinding and hydrothermal treatment for the solid raw materials, and accordingly is considered as one of the most promisingly green and sustainable synthesis strategy for the metal-doped zeolite materials. However, there are scarcely any reports on the solvent-free synthesis and catalytic application of tungsten-doped zeolite materials. In this work, tungsten-doped MFI zeolites were prepared with solvent-free synthesis method and used as heterogeneous catalyst for cyclohexene epoxidation reaction. The synthesized tungsten-doped MFI zeolites displayed a monoclinic (P21/n) space group attributed to the successful incorporation of tungsten atom into MFI framework and meanwhile possessed an enormous number of irregular mesopores ranging from 2 nm to 50 nm. The influence of TPAOH addition amount on the mesopore structure and properties of tungsten-doped MFI zeolite was further investigated. In addition, the crystallization process of tungsten-doped MFI zeolite sample was tracked and analyzed with SEM, XRD and BET characterizations, and accordingly possible formation process for hierarchical zeolite was proposed. Furthermore, the prepared hierarchical tungsten-doped MFI zeolite displayed eminent cyclohexene epoxidation performance and re-usability for more than five times. This work provides some guidance for the solvent-free synthesis of metallosilicate zeolites, decreasing the generation of wastewater and improving the zeolite yield. Rapid growth of WS 50-0.20-24h crystal particles synthesized with solvent-free method is mainly concentrated in the first 2 h of crystallization. [Display omitted] • Hierarchical tungsten-doped MFI zeolite was synthesized with solvent-free method. • Tungsten-doped MFI zeolite revealed a monoclinic (P21/n) space group. • Tungsten-doped MFI zeolite displayed eminent catalytic activity and re-usability. [ABSTRACT FROM AUTHOR]