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Deep eutectic solvents (DESs) hold the potential to serve as a sustainable and environmentally friendly substitute for supercritical fluids, ionic liquids, and organic solvents. Moreover, DESs have been demonstrated to assist in stabilizing the structure of enzyme. The enzymatic synthesis of epoxy vegetable oil in a DES‐system was developed in this study, and the influence of DESs viscosity on the epoxidation system was investigated for the first time. The results demonstrated that the epoxy value reached 8.97, and the double bond conversion rate was 82.48%. The viscosity of the reaction system decreased from 209.32 to 91.35 (mPa·s). The application of DES in epoxidation was confirmed through structural characterization, indicating that eutectic solvents could serve as substitutes for toxic and volatile organic solvents in synthesizing high‐epoxide vegetable oils using an enzymatic method, thus facilitating the production of environmentally friendly plasticizers.

This review concentrates on success stories from the synthesis of approved medicines and drug candidates using epoxide chemistry in the development of robust and efficient syntheses at large scale. The focus is on those parts of each synthesis related to the substrate-controlled/diastereoselective and catalytic asymmetric synthesis of epoxide intermediates and their subsequent ring-opening reactions with various nucleophiles. These are described in the form of case studies of high profile pharmaceuticals spanning a diverse range of indications and molecular scaffolds such as heterocycles, terpenes, steroids, peptidomimetics, alkaloids and main stream small molecules. Representative examples include, but are not limited to the antihypertensive diltiazem, the antidepressant reboxetine, the HIV protease inhibitors atazanavir and indinavir, efinaconazole and related triazole antifungals, tasimelteon for sleep disorders, the anticancer agent carfilzomib, the anticoagulant rivaroxaban the antibiotic linezolid and the antiviral oseltamivir. Emphasis is given on aspects of catalytic asymmetric epoxidation employing metals with chiral ligands particularly with the Sharpless and Jacobsen–Katsuki methods as well as organocatalysts such as the chiral ketones of Shi and Yang, Pages’s chiral iminium salts and typical chiral phase transfer agents.

Titanosilicate-supported Au-cluster catalysts can be used to selectively synthesize propylene oxide from propylene using O 2 and H 2 . However, the details of the catalytic reaction mechanism have not yet been elucidated. Thus, the reaction mechanism was investigated using density functional theory calculations. The calculation results revealed that active Ti-OOH forms on the surface Ti site, which is active as an oxidant and acts as an anchorage site for Au nanoclusters. The rate-determining step of propylene oxide synthesis on Au/titanosilicate is O insertion into propylene, with an activation energy of 1.37 eV. The propylene involved in this reaction is activated by adsorption on Au nanoclusters. Moreover, it was also found that the formation of Ti-OOH on Au/titanosilicate requires an activation energy of 0.48 eV, while it is barrierless on Au/anatase-TiO 2 . However, the decomposition energy of Ti-OOH on Au/titanosilicate is −0.16 eV, which is smaller than that on Au/anatase-TiO 2 (−1.12 eV). The results indicate that Ti-OOH decomposes more readily on Au/titanosilicate than on Au/anatase-TiO 2 but is easily regenerated because the reaction energy is significantly smaller than that on Au/anatase-TiO 2 . Therefore, these calculations are qualitatively in good agreement with the experimental results for Au/titanosilicate, which exhibited high catalytic activity at high temperatures. Graphical Abstract

Hierarchical Ce-containing TS-1 catalysts were successfully prepared by combining the skeleton metal doping and alkali treatment strategies. The amount of metal doping and alkali solution concentration were adjusted to optimize the ratio of samples. The modified samples were characterized by using various techniques such as XRD, SEM, TEM, and XPS, which revealed that the modified samples contained 2–4 nm mesopores with a grain size of about 150 nm. The positive relationship between the amount of Ce doped and the cell parameters confirms the successful doping of Ce into the TS-1 zeolite skeleton. Furthermore, the modified molecular sieves showed weaker acidity and stronger hydrophobicity. Then, the experiments to evaluate the epoxidation reaction of hierarchical TS-1 molecular sieve containing Ce on long-chain olefins (n-pentene, n-hexene) as well as cyclic olefins (cyclopentene, cyclohexene) were investigated using H2O2 as the oxidant. The modified samples exhibited higher conversion of large olefins and selectivity of epoxides compared with untreated TS-1. Therefore, the accessibility of the active center after the complex modification and the synergistic catalytic effect of the metal Ti with Ce can be verified. On this basis, the catalyst was tested in batch operation for five cycles to investigate the reusability performance, and the results showed a slight decrease in yield. After roasting at 550 °C, the initial catalytic activity of the previous cycle was fully recovered. This study provides an inexpensive catalyst for the epoxidation of long-chain olefins, laying the foundation for its commercial application.Preparation method and epoxidation reaction route of hierarchieal cerium containing TS-1 catalyst.

A hybrid catalyst based on Mo132 as a Keplerate type polyoxometalate and MimAm as an ionic liquid was used as an effective catalyst for selective epoxidation of different alkenes with H 2 O 2 as a green and safe oxidant. The effects of various parameters such as catalyst, oxidant amounts, reaction time, and temperature were also studied in selective epoxidation of cyclooctene. Moreover, under the optimal reaction conditions, the epoxidation of different alkenes was performed with 54–100% yields. Interestingly, this catalyst complies with the benefits of easy preparation, recovery, recycle, high catalytic activity, simplified workup, and flexible composition. Graphical Abstract

Molybdenum coordination compounds, [MoO 2 L 1 (CH 3 OH)] ( 1 ) and [MoO 2 L 2 (CH 3 OH)]0.5(CH 3 OH) ( 2 ), were obtained by the reaction of molybdenum trioxide with ONO-donor ligands [H 2 L 1  = ( E )-4-amino- N' -(5-bromo-2-hydroxybenzylidene)benzohydrazide and H 2 L 2  = ( E )-4-amino- N' -(2-hydroxynaphthalen-1-yl)methylene)benzohydrazide]. The structures of 1 and 2 were determined by single crystal X-ray analysis and they further characterized by elemental analysis (carbon, hydrogen and nitrogen) and spectroscopic methods such as FT-IR, UV–Vis and NMR analyses. According to the structural analyses, a free amine functionality (Ph-NH 2 ) was present in the structure of compounds 1 and 2 . Therefore, compounds 1 and 2 were supported on the surface of functionalized silica gel by amidification reaction. The obtained supported catalysts ( Si-Mo-1 and Si-Mo-2 ) were characterized by XPS, XRD, EDX, DRS, TGA and FT-IR analyses. The obtained supported catalysts ( Si-Mo-1 and Si-Mo-2 ) were tested in the epoxidation of olefins using aqueous TBHP oxidant. Some effective parameters on the selectivity and activity of Si-Mo-1 and Si-Mo-2 like the effect of the concentration of catalyst and oxidant, temperature and solvent were studied. The supported catalysts were easily recovered from the mixture of the reaction by filtration and the recovered catalysts were also characterized by various analyses. The results indicated that the supported catalysts ( Si-Mo-1 and Si-Mo-2 ) are selective and effective catalysts for epoxidation of olefins. Graphical Abstract

The metal-organic frameworks (MOFs) with oxidative and acidic active sites demonstrate promising potential for tandem reactions involving olefin oxidation carboxylation. In this study, M-BTCs were synthesized via a solvothermal method, employing 1,3,5-benzenetricarboxylic acid (H 3 BTC) as a ligand in combination with various metals (Mn, Co, Cu, Ni). The good thermal stability and morphology of M-BTC was verified by various characterization techniques, and its catalytic performance was evaluated for oxidative carboxylation. The catalytic activity of Mn-BTC, with Mn 3+ / Mn 2+ as the primary oxidation site, was found to be superior in both olefin epoxidation and CO 2 cycloaddition. The effects of reaction conditions on both epoxidation of styrene and the cycloaddition reaction were investigated, respectively. Under optimal reaction conditions (epoxidation: 10 wt% Mn-BTC of styrene, 80 ℃ for 12 h; cycloaddition: 100 ℃ for 12 h with a CO 2 flow rate of 15 ml/min and tetrabutylammonium bromide (TBAB) amount of 15 mol%), a 53% yield of styrene carbonate (SC) was obtained in the assisted tandem reactions. Furthermore, cycling experiments as well as XRD and FT-IR spectra of the catalysts after use demonstrated that Mn-BTC maintained its crystal structure and retained a yield of 49% SC after three cycles. Finally, a possible mechanism for assisted tandem catalytic reaction over Mn-BTC was proposed. Graphic Abstract

In this work, the addition of 5%SiO 2 to 7.5%WO 3 -ZrO 2 catalyst increased the content of tetragonal ZrO 2 and BET, which could promote the formation of W–O–Zr(Si) bonds between WO x species and 5%SiO 2 -ZrO 2 material, thus reducing the degree of aggregation of WO x species. The oligomerized WO x species on the 7.5%WO 3 -5%SiO 2 -ZrO 2 catalyst could not only remain stable, but also provided stable Lewis acid for the activation of hydrogen peroxide and maleic anhydride for epoxidation. In addition, the Si–O–Zr bond on SiO 2 -modified 7.5%WO 3 -ZrO 2 catalyst could provide an additional Brønsted acid site for activating the hydrolysis of epoxysuccinic acid to DL-tartaric acid. Therefore, the DL-tartaric acid yield of SiO 2 -modified 7.5%WO 3 -ZrO 2 catalyst was higher than that of 7.5%WO 3 -ZrO 2 catalyst, and also higher than that of Na 2 WO 4 catalyst. Graphical Abstract The SiO 2 -modified 7.5%WO 3 -ZrO 2 catalyst rich in stable Lewis and Brønsted acid not only had good cyclic stability but also had good catalytic activity under mild condition.

WOx has good performance in olefin epoxidation, however, the presence of a large amount of Brönsted acid on WOx affects the selectivity of epoxy products. In this paper, broken carbon spheres (b-C spheres) treated with nitric acid were used as support to anchor WOx in dynamic solvothermal process. Based on GC–MS and GC-IR detection, the obtained WOx/C greatly increased selectivity of 1,2-epoxyhexane from 16.0% (pure WOx) to 92.1% in epoxidation of 1-hexene. The improvement of WOx performance is attributed to the reduction of Brönsted acid sites and electron cloud density after loading, which may all result from interaction between WOx and oxygen-containing functional groups of b-C spheres. Above changes not only effectively inhibit the hydrolysis of 1,2-epoxyhexane, but also are conducive to nucleophilic reaction of H2O2 to WOx, which is beneficial to the activation of H2O2. Finally, an epoxidation mechanism with oxygen vacancies as the main route under WOx/C catalysis is reasonably proposed.

In this work, a functionalized gallium metal–organic framework with active dioxo-molybdenum (VI) centers was evaluated as a catalyst in the epoxidation of soybean oil using tert-butyl-hydroperoxide as an oxidizing agent. The influence of the reaction time, temperature, and concentration of the oxidizing agent was studied, and it was demonstrated that the highest epoxide selectivity was obtained at 110 °C after 4 h of reaction (29% conversion and 91% selectivity) using a soybean oil/oxidizing agent ratio of 1/2. The stability of the metal–organic framework was confirmed by infrared spectroscopy, X-ray powder diffraction, thermogravimetric analysis, scanning electron microscopy, and energy-dispersive X-ray spectroscopy EDS. The stability tests demonstrated that the catalyst could be reused in the catalytic process for the recovery of vegetable oils.