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Hydrofluoroolefins (HFOs) are important synthetic compounds replacing other halocarbons in phase-down from usage (e.g., as refrigerants, propellants, foam blowing). Little is known about their atmospheric abundance, distribution and trends, nor about their emissons. Here, we report atmospheric observations of the widely used HFO-1234yf (2,3,3,3-tetrafluoroprop-1-ene), and HFO-1234ze(E) (E-1,3,3,3-tetrafluoroprop-1-ene), and the hydrochlorofluoroolefin (HCFO) HCFO-1233zd(E) (E-1-chloro-3,3,3-trifluoroprop-1-ene) observed as part of the Advanced Global Atmospheric Gases Experiment (AGAGE) network. Over the observational period 2011-2025, pollution events have grown in magnitude and frequency at sites which are influenced by regional emissions, while remote stations show first appearances of these substances. By 2024/2025 winter peak mole fractions in background northern hemisphere air have reached â¼ 0.25 ppt (picomol mol.sup.-1, parts-per-trillion in dry air) for HFO-1234yf and HFO-1234ze(E) and â¼ 0.45 ppt for HCFO-1233zd(E). Using European observations and the inverse modeling frameworks InTEM, ELRIS, and RHIME we determine emission trends and regional distributions. For Northwest Europe, emissions of HFO-1234yf increased steadily and rapidly from <0.1 Gg yr.sup.-1 in 2014 to 1.50 [1.23-1.74, range of 16-84 percentile] Gg yr.sup.-1 by 2023, presumably due to its introduction in mobile air conditioning and stationary refrigeration. HFO-1234ze(E) emissions were low during 2014-2017, followed by a rapid increase in 2018/2019, potentially due its introduction as an aerosol propellant, after which they increased more slowly to 0.96 [0.82-1.13] Gg yr.sup.-1 by 2023. HCFO-1233zd(E) emissions are derived from 2017 onward, showing a steady increase from 0.15 [0.07-0.23] to 1.04 [0.93-1.15] Gg yr.sup.-1 in 2023.

A novel and efficient 1,2-oxidative trifluoromethylation of olefins employing Ag(O[sub.2]CCF[sub.2]SO[sub.2]F) as a trifluoromethyl source is described with O[sub.2] as the oxidant, which provides access to a variety of valuable α-trifluoromethyl-substituted ketones. The broad substrate scope, feasibility of large-scale operation, and derivatization reactions of α-trifluoromethyl ketones demonstrate the promising utility of this protocol.

Herein, we report the copper-catalyzed dehydrogenative C(sp[sup.2])–N bond formation of 4-pentenamides via nitrogen-centered radicals. This reaction provides a straightforward and efficient preparation method for γ-alkylidene-γ-lactams. Notably, we could controllably synthesize α,β-unsaturated- or α,β-saturated-γ-alkylidene-γ-lactams depending on the reaction conditions.

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.sub.2O.sub.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.

The bifunctional catalyst Ru/H was prepared by equal volume impregnation method and applied to the study of the kinetics of benzene hydroalkylation reaction. The reaction order of 1 for benzene and 1.94 for H.sub.2 ( [Formula omitted]) was obtained by fitting the kinetic experimental data first. Then a kinetic model conforming to the Eley-Rideal (E-R) mechanism was developed based on the types of adsorbates on different active centers of the solid catalyst, and the main mechanism was that the benzene in the adsorbed state was partially hydrogenated to produce cyclohexene, which was not desorbed from the active centers. Some of it was further hydrogenated to produce cyclohexane, and some was alkylated with benzene in the bulk phase to produce cyclohexylbenzene. The reaction rate control step was the alkylation of benzene and cyclohexene. The model parameters were calculated using a genetic algorithm. The model was tested to be able to describe the reaction mechanism of benzene hydroalkylation well and to provide guidance for process optimization.

Cleavage of C=C bond of styrene and its derivatives into two carbonyl compounds with [H.sub.2][O.sub.2] is accomplished at mild conditions using Vanadyl(IV) acetylacetonate anchored SBA-15 catalyst, which is prepared and characterized by BET surface area, low angle XRD and FT-IR. It is a highly efficient, recyclable and reusable catalyst.

The regioselectivity and molecular mechanism of the (3+2) cycloaddition reaction between E-2-(trimethylsilyl)-1-nitroethene and arylonitrile N-oxides were explored on the basis of the ωB97XD/6-311+G(d) (PCM) quantumchemical calculations. It was found that the earlier postulate regarding the regioselectivity of the cycloaddition stage should be undermined. Within our research, several aspects of the title reaction were also examined: interactions between reagents, electronic structures of alkenes and nitrile oxides, the nature of transition states, the influence of the polarity solvent on the reaction selectivity and mechanism, substituent effects, etc. The obtained results offer a general conclusion for all of the important aspects of some groups of cycloaddition processes.

In this research, microorganisms were used to produce Gd.sub.2ZnMnO.sub.6 NFs in a biological process instead of a chemical method as a nanocatalyst. Considering the capability of the microorganisms to synthesize nanofibrous (NFs) upon exposure to metal ions, microorganisms were employed to produce Gd.sub.2ZnMnO.sub.6 NFs through a biological process. The utilization of chemical modification to fabricate environmentally friendly heterogeneous nanocatalysts has proven to be highly appealing in the context of synthesizing 3-aryl-2-oxazolidinones using alkenes, carbon dioxide, and amines in an aqueous solution. The role of diverse variables in the creation of 3-aryl-2-oxazolidinones has been thoroughly investigated. Notably, Gd.sub.2ZnMnO.sub.6 NFs demonstrates remarkable efficiency in the production of 3-aryl-2-oxazolidinones due to its unique morphology. The morphology of Gd.sub.2ZnMnO.sub.6 NFs contributed to the creation of a desirable outer layer for the creation of 3-aryl-2-oxazolidinones. The findings demonstrated that the utilization of Gd.sub.2ZnMnO.sub.6 nanofibers positively impacts the effectiveness of the creation of 3-aryl-2-oxazolidinones. This can be attributed to the nanofibers' impressive mechanical and ionic internal characteristics, as well as their exceptional thermal sustainability and persistent colloidal sturdiness. Consequently, employing the host-guest method, the system could be regarded as an exemplary nanocatalyst. A diverse array of olefins was successfully transformed into desirable products, independent of the electronic nature of the substitutes. The involvement of heterogeneous mixtures did not impede the progression of the reaction. Moreover, the 3-aryl-2-oxazolidinones were easily distinguished from the Gd.sub.2ZnMnO.sub.6 nanofibers, and the medium exhibited the ability to undergo multiple cycles of usage without experiencing a notable decline in their catalytic activity and selectivity. This approach offers notable advantages, including a strong economic capability and the potential to withstand functional groups.

The reactions of 4-aryl-1-tosyl-1,2,3-triazoles with substituted primary 2- or 4-nitroanilines, catalyzed by dirhodium tetrapivalate were used to synthesize stable (Z)-N-aryl-N'-tosylethene-1,2-diamines. The analogous reaction of 4-phthalimido-1-tosyl-1H-1,2,3-triazole with 2-bromo-4-nitroaniline proceeded upon heating in the absence of catalyst, providing the first example for non-catalytic insertion of a carbene generated from 1-sulfonyl-1,2,3-triazole into an N-H bond. All ethene-1,2-diamines were isolated without resorting to chromatographic purification. The synthesized ethene-1,2-diamines contained two NH groups in a cis relationship and present interest as new bidentate ligands, as well as substrates for the synthesis of N,N-heterocycles.