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A variety of 3-hydroxy-isoindolin-1-one derivatives were synthesized using the photodecarboxylative addition of carboxylates to phthalimide derivatives in aqueous media. Subsequent acid-catalyzed dehydration furnished 3-(alkyl and aryl)methyleneisoindolin-1-ones with variable E-diastereoselectivity in good to excellent overall yields. Noteworthy, the parent 3-phenylmethyleneisoindolin-1-one underwent isomerization and oxidative decomposition when exposed to light and air. Selected 3-hydroxy-isoindolin-1-one and 3-(alkyl and aryl)methyleneisoindolin-1-one derivatives showed moderate antibacterial activity that justifies future elaboration and study of these important bioactive scaffolds. [ABSTRACT FROM AUTHOR]

We report a user‐friendly approach for the decarboxylative formation of stereodefined and complex tri‐ and tetra‐substituted olefins from vinyl cyclic carbonates and amines as radical precursors. The protocol relies on easy photo‐initiated α‐amino‐radical formation followed by addition onto the double bond of the substrate resulting in a sequence involving carbonate ring‐opening, double bond relay, CO2 extrusion and finally O‐protonation. The developed protocol is efficient for both mismatched and matched polarity substrate combinations, and the scope of elaborate stereodefined olefins that can be forged including drug‐functionalized derivatives is wide, diverse and further extendable to other types of heterocyclic and radical precursors. Mechanistic control reactions show that the decarboxylation step is a key driving force towards product formation, with the initial radical addition under steric control. [ABSTRACT FROM AUTHOR]

We report a user‐friendly approach for the decarboxylative formation of stereodefined and complex tri‐ and tetra‐substituted olefins from vinyl cyclic carbonates and amines as radical precursors. The protocol relies on easy photo‐initiated α‐amino‐radical formation followed by addition onto the double bond of the substrate resulting in a sequence involving carbonate ring‐opening, double bond relay, CO2 extrusion and finally O‐protonation. The developed protocol is efficient for both mismatched and matched polarity substrate combinations, and the scope of elaborate stereodefined olefins that can be forged including drug‐functionalized derivatives is wide, diverse and further extendable to other types of heterocyclic and radical precursors. Mechanistic control reactions show that the decarboxylation step is a key driving force towards product formation, with the initial radical addition under steric control. [ABSTRACT FROM AUTHOR]

Here in, we describe the photochemical decarboxylative alkylation of quinoxalin‐2(1H)‐ones using commercially accessible carboxylic acids with oxygen as sole oxidant through energy transfer process. The coupling of diverse array of alkyl carboxylic acids (1° to 3°) and bioactive acids with quinoxalin‐2(1H)‐ones is successfully accomplished to achieve the desired alkylated products. [ABSTRACT FROM AUTHOR]

This study reports the copper‐catalyzed α‐indolmethylation of 2‐pyridylacetates with 3‐indoleacetic acids. This reaction offers an approach to generating alkylideneindolenine electrophiles via the oxidative decarboxylation of 3‐indoleacetic acids. The developed reaction system demonstrates good versatility, extending beyond the indolmethylation of 2‐pyridylacetates to include activated esters and nitroalkanes. Moreover, a biological evaluation revealed that several products exhibited antiproliferative activity against different cancer cell lines. [ABSTRACT FROM AUTHOR]

This work demonstrates the oxidative cross‐coupling of cinnamic acids with toluene using FeCl3 immobilized on a covalent organic framework (COF) pore wall, resulting in the synthesis of 1,3‐arylpropene derivatives. This iron‐based heterogeneous catalytic system affords the desired products in moderate yields ranging from 51 % to 65 %. Investigations using COFs with varying pore sizes indicate that larger pores facilitate the reaction, suggesting a spatial requirement for this transformation within the catalyst. The correlation between pore size and reaction efficiency provides insights into developing tailored catalysts to match the spatial requirements of the transformation. This version emphasizes the novelty of the study and the synthesis of 1,3‐arylpropene derivatives. It also clarifies that the iron‐based heterogeneous catalytic system is responsible for the reaction. Additionally, it provides a more detailed explanation of the findings regarding pore size and spatial requirements. [ABSTRACT FROM AUTHOR]

In this paper, the foam-like multi-stage porous 3wt%Al-KIT-6-4T(WI) catalyst was prepared and employed for efficient catalyzing biomass-derived GVL to butene. It is found that the prepared 3wt%Al-KIT-6-4T(WI) catalyst possess abundant mesoporous and presented the foam-like microstructure. Due to this, the 3wt%Al-KIT-6-4T(WI) catalyst has large specific surface area (517.09 m2·g−1) and adequate amount of surface acid sites (both Brønsted and Lewis acid site). The special microstructure further improves the mass transfer efficiency of reactants and products. Under the optimized reaction conditions, the butene yield over the 3wt%Al-KIT-6-4T(WI) catalyst can up to 93.78% at 300 °C, after reacting 240 min. Moreover, the 3wt%Al-KIT-6-4T(WI) catalyst still showed excellent regeneration stability, and above 72% butene yield can be maintained after 7th cycle tests. [ABSTRACT FROM AUTHOR]

Copper‐catalyzed decarboxylation of peroxides in the presence of O‐methyl‐N‐nitroisourea provides an access to O‐methyl‐N‐alkylnitroisoureas, an underdeveloped class of nitrogenated compounds, which can be regarded as isocyanate surrogates and find useful as AB‐type monomers, for polyurethane synthesis. [ABSTRACT FROM AUTHOR]

Paired redox‐neutral electrolysis offers an attractive green platform for organic synthesis by avoiding sacrificial oxidants and reductants. Carboxylates are non‐toxic, stable, inexpensive, and widely available, making them ideal nucleophiles for C−C cross‐coupling reactions. Here, we report the electro/Ni dual‐catalyzed redox‐neutral decarboxylative C(sp3)−C(sp2) cross‐coupling reactions of pristine carboxylates with aryl bromides. At a cathode, a NiII(Ar)(Br) intermediate is formed through the activation of Ar−Br bond by a NiI‐bipyridine catalyst and subsequent reduction. At an anode, the carboxylates, including amino acid, benzyl carboxylic acid, and 2‐phenoxy propionic acid, undergo oxidative decarboxylation to form carbon‐based free radicals. The combination of NiII(Ar)(Br) intermediate and carbon radical results in the formation of C(sp3)−C(sp2) cross‐coupling products. The adaptation of this electrosynthesis method to flow synthesis and valuable molecule synthesis was demonstrated. The reaction mechanism was systematically studied through electrochemical voltammetry and density functional theory (DFT) computational studies. The relationships between the electrochemical properties of carboxylates and the reaction selectivity were revealed. The electro/Ni dual‐catalyzed cross‐coupling reactions described herein expand the chemical space of paired electrochemical C(sp3)−C(sp2) cross‐coupling and represent a promising method for the construction of the C(sp3)−C(sp2) bonds because of the ubiquitous carboxylate nucleophiles and the innate scalability and flexibility of electrochemical flow‐synthesis technology. [ABSTRACT FROM AUTHOR]

Paired redox‐neutral electrolysis offers an attractive green platform for organic synthesis by avoiding sacrificial oxidants and reductants. Carboxylates are non‐toxic, stable, inexpensive, and widely available, making them ideal nucleophiles for C−C cross‐coupling reactions. Here, we report the electro/Ni dual‐catalyzed redox‐neutral decarboxylative C(sp3)−C(sp2) cross‐coupling reactions of pristine carboxylates with aryl bromides. At a cathode, a NiII(Ar)(Br) intermediate is formed through the activation of Ar−Br bond by a NiI‐bipyridine catalyst and subsequent reduction. At an anode, the carboxylates, including amino acid, benzyl carboxylic acid, and 2‐phenoxy propionic acid, undergo oxidative decarboxylation to form carbon‐based free radicals. The combination of NiII(Ar)(Br) intermediate and carbon radical results in the formation of C(sp3)−C(sp2) cross‐coupling products. The adaptation of this electrosynthesis method to flow synthesis and valuable molecule synthesis was demonstrated. The reaction mechanism was systematically studied through electrochemical voltammetry and density functional theory (DFT) computational studies. The relationships between the electrochemical properties of carboxylates and the reaction selectivity were revealed. The electro/Ni dual‐catalyzed cross‐coupling reactions described herein expand the chemical space of paired electrochemical C(sp3)−C(sp2) cross‐coupling and represent a promising method for the construction of the C(sp3)−C(sp2) bonds because of the ubiquitous carboxylate nucleophiles and the innate scalability and flexibility of electrochemical flow‐synthesis technology. [ABSTRACT FROM AUTHOR]

Using a set of conformationally restricted Proline‐derived Modules (ProMs), our group has recently succeeded in developing inhibitors for the enabled/vasodilator‐stimulated phosphoprotein homology 1 (EVH1) domain, which is a key mediator of cell migration and plays an important role in tumor metastasis. While these (formally) pentapeptidic compounds show nanomolecular binding affinities towards EVH1, their drug‐like properties and cell permeability need to be further optimized before they can be clinically tested as therapeutic agents against metastasis. In this study, we sought to improve these properties by removing the C‐terminal carboxylic acid function of our peptoids, either by late‐stage decarboxylation or by direct synthesis. For late‐stage decarboxylation of ProM‐like systems, a method for reductive halo decarboxylation was optimized and applied to several proline‐derived substrates. In this way, a series of new decarboxy ProMs suitable as building blocks for decarboxy EVH1 inhibitors were obtained. In addition, we incorporated decarboxy‐ProM‐1 into the pentapeptide‐like compound Ac[2ClF][ProM‐2][Decarb‐ProM‐1], which showed similar affinity towards EVH1 as the methyl ester derivative (Ac[2Cl‐F][ProM‐2][ProM1]OMe). However, despite better calculated drug‐like properties, this compound did not inhibit chemotaxis in a cellular assay. [ABSTRACT FROM AUTHOR]

The Pd‐catalysed decarboxylative asymmetric allylic alkylation (DAAA) has been applied to the enantioselective synthesis of sterically hindered benzofuran‐3(2H)‐one‐derived α‐aryl‐β‐keto esters employing the (R,R)‐ANDEN phenyl Trost ligand. A range of substrates were synthesised, employing previously developed aryllead triacetate methodology to install various aryl groups. The resulting α‐aryl‐α‐allyl benzofuran‐3(2H)‐one DAAA products were obtained in moderate to high yields and in enantioselectivities of up to 96 % ee, with the best results observed for substrates containing a di‐ortho‐substitution pattern on the aryl ring as well as naphthyl‐containing substrates. [ABSTRACT FROM AUTHOR]

We demonstrate that electrochemical‐induced decarboxylation enables reliable post‐polymerization modification and degradation of polymers. Polymers containing N‐(acryloxy)phthalimides were subjected to electrochemical decarboxylation under mild conditions, which led to the formation of transient alkyl radicals. By installing these redox‐active units, we systematically modified the pendent groups and chain ends of polyacrylates. This approach enabled the production of poly(ethylene‐co‐methyl acrylate) and poly(propylene‐co‐methyl acrylate) copolymers, which are difficult to synthesize by direct polymerization. Spectroscopic and chromatographic techniques reveal these transformations are near‐quantitative on several polymer systems. Electrochemical decarboxylation also enables the degradation of all‐methacrylate poly(N‐(methacryloxy)phthalimide‐co‐methyl methacrylate) copolymers with a degradation efficiency of >95 %. Chain cleavage is achieved through the decarboxylation of the N‐hydroxyphthalimide ester and subsequent β‐scission of the backbone radical. Electrochemistry is thus shown to be a powerful tool in selective polymer transformations and controlled macromolecular degradation. [ABSTRACT FROM AUTHOR]

We demonstrate that electrochemical‐induced decarboxylation enables reliable post‐polymerization modification and degradation of polymers. Polymers containing N‐(acryloxy)phthalimides were subjected to electrochemical decarboxylation under mild conditions, which led to the formation of transient alkyl radicals. By installing these redox‐active units, we systematically modified the pendent groups and chain ends of polyacrylates. This approach enabled the production of poly(ethylene‐co‐methyl acrylate) and poly(propylene‐co‐methyl acrylate) copolymers, which are difficult to synthesize by direct polymerization. Spectroscopic and chromatographic techniques reveal these transformations are near‐quantitative on several polymer systems. Electrochemical decarboxylation also enables the degradation of all‐methacrylate poly(N‐(methacryloxy)phthalimide‐co‐methyl methacrylate) copolymers with a degradation efficiency of >95 %. Chain cleavage is achieved through the decarboxylation of the N‐hydroxyphthalimide ester and subsequent β‐scission of the backbone radical. Electrochemistry is thus shown to be a powerful tool in selective polymer transformations and controlled macromolecular degradation. [ABSTRACT FROM AUTHOR]

A catalyst-, oxidant-free and green synthetic route for direct access to a series of novel imidazopyridine-linked coumarins has been devised through tandem C(sp2)–H functionalization/decarboxylation reaction in ethyl acetate as a sustainable medium. Moreover, the utilities of ensured products in further organic synthesis were conducted by Suzuki–Miyaura and Sonogashira cross-coupling reactions. The fluorescence characteristics of the produced molecules are appropriate, and the synthesized scaffolds could promisingly garner future attention in clinical diagnostics and bioimaging research. [ABSTRACT FROM AUTHOR]

The decarboxylation dynamics of the doubly deprotonated fluorescein dianion, Fl2−, are investigated by recording fragment action spectra for the anion, Fl−, and its decarboxylated analog, Fl–CO2−, using a new reflectron secondary mass spectrometer. The formation of the anion, Fl−, is directly investigated by photoelectron imaging. The Fl− and Fl–CO2− action spectra indicate that, for λ < 400 nm, one-photon dissociative photodetachment, i.e., simultaneous decarboxylation and electron loss, competes with photodetachment, whereas for λ > 400 nm, decarboxylation only proceeds following electron loss via a sequential two-photon process. The primary decarboxylation pathway is the ready loss of CO2 from the relatively short-lived intermediate excited state, Fl−[D1], which is formed by electron loss from the dianion via resonant tunneling through the repulsive Coloumb barrier associated with a high-lying excited dianion state, Fl2−[S2]. [ABSTRACT FROM AUTHOR]

AbstractMany organic reactions rely on CO2 sources to generate important structural units and valuable chemicals. In this study, we compared the effects of cannabidiol (CBD) and cannabidiolic acid (CBDA) on the supercritical CO2 (scCO2)-induced de/carboxylation reaction. The results showed that CBD was directly carboxylated in the ortho-position to form CBDA with up to 62% conversion. Meanwhile, CBDA decarboxylation occurred on hemp plant material via varying composition. Mechanistic studies revealed that CBD carboxylation was influenced not only by the physical properties of scCO2, but also by the vegetable matrix. [ABSTRACT FROM AUTHOR]

The decarboxylative addition of substituted malonic acid half oxyesters (SMAHOs) to dialkyl azodicarboxylates is described. The reaction was promoted by 1,4‐diazabicyclo[2.2.2]octane (DABCO) as an organocatalyst in heated toluene. High yields of the coupling products were generally obtained, and the scope of the reaction proved rather important with the potential presence of functionalized side chains at the α‐position, affording an original access to α‐aminoester derivatives. [ABSTRACT FROM AUTHOR]

A novel Au-allenylidene promoted decarboxylative annulation by intramolecular α-nucleophilic addition has been disclosed. The unsaturated cyclic ethynylethylene carbamates/carbonates can be converted to unique nucleophiles attached with alkylidene ketenes by sequential decarboxylation and oxidation processes. Such alkylidene ketenes can be rapidly trapped by intramolecular α-attacking annulation to generate potential biological active unsaturated γ-lactams/lactones with broad scope, facile post-modification, high regioselectivity and efficiency. [ABSTRACT FROM AUTHOR]

Herein, we present the first examples of amino acid decarboxylation via photochemically activated carbonyl sulfide (COS) elimination of the corresponding thioacids. This method offers a mild approach for the decarboxylation of amino acids, furnishing N-alkyl amino derivatives. The methodology was compatible with amino acids displaying both polar and hydrophobic sidechains and was tolerant towards widely used amino acid-protecting groups. The compatibility of the reaction with continuous-flow conditions demonstrates the scalability of the process. [ABSTRACT FROM AUTHOR]

Certain cancer cells within solid tumors experience hypoxia, rendering them incapable of oxidative phosphorylation (OXPHOS). Despite this oxygen deficiency, these cells exhibit biochemical pathway activity that relies on NAD+. This mini-review scrutinizes the persistent, residual Complex I activity that oxidizes NADH in the absence of oxygen as the electron acceptor. The resulting NAD+ assumes a pivotal role in fueling the α-ketoglutarate dehydrogenase complex, a critical component in the oxidative decarboxylation branch of glutaminolysis — a hallmark oncometabolic pathway. The proposition is that through glutamine catabolism, high-energy phosphate intermediates are produced via substrate-level phosphorylation in the mitochondrial matrix substantiated by succinyl-CoA ligase, partially compensating for an OXPHOS deficiency. These insights provide a rationale for exploring Complex I inhibitors in cancer treatment, even when OXPHOS functionality is already compromised. [ABSTRACT FROM AUTHOR]

The triplet‐sensitized (by the solvent acetone) as well as the direct (λex=300–320 nm) photochemical decarboxylation of N‐phthaloylated γ‐aminobutyric acid (GABA) derivatives are versatile and high‐yielding routes to benzopyrrolizidines via intramolecular electron transfer initiated decarboxylation followed by radical coupling. The ß‐mono‐ and ß,ß'‐disubstituted N‐phthaloyl GABA derivatives 7 a–7 g, respectively, were applied as substrates. Decarboxylative photocyclization yielded hydroxy benzopyrrolizidines 8 a–8 g in high chemical yields and with moderate diastereoselectivities from the ß‐monosubstituted substrates. The analogous α‐substituted GABA derivatives 11 a–11 c were also applied as potential substrates for memory of chirality effects. The reaction quantum yields of the photodecarboxylation reactions for the parent GABA derivative 13 and for the new substrates 7 h and 11 a were determined by the quantum yield determination system (QYDS) and showed a remarkable concentration dependency indicating aggregation at higher substrate concentrations. Inhibition studies on the atherogenic human serine hydrolase cholesterol esterase showed derivatives 8 a and 8 d to exhibit a hyperbolic mode of inhibition with moderate IC50 values of about 60–80 μM. [ABSTRACT FROM AUTHOR]

A facile and novel method was established for the synthesis of triazolinone scaffolds through [3 + 2] cycloaddition of C,N-cycloazomethylimines with dioxazolones in the presence of CH3ONa. In these transformations, isocyanates were formed in situ by the decarboxylation and Curtius rearrangement of dioxazolones. Importantly, the isocyanate formed from dioxazolone is employed for the first time for the cyclization instead of the widely used N-acyl nitrenes. The newly developed [3 + 2] cycloaddition is applicable to a broad range of substrates with high functional group tolerance, providing various triazolinones in good to excellent yields (up to 94%). Additionally, this method is easy to operate, green, environmentally friendly, and avoids highly toxic reagents. [ABSTRACT FROM AUTHOR]

A practical synthesis of (±)-entecavir has been developed on the basis of Corey (±)-lactone diol. The key stage is the synthesis of (1R*,3R*,4S*)-4-(1-ethoxyethoxy)-3-[(1-ethoxyethoxy)methyl]-2-methylidene-cyclo-pentan-1-ol by oxidative decarboxylation of 2-{(1S*,2R*,3S*,5R*)-5-{[tert-butyl(dimethyl)silyl]oxy}-3-(1-ethoxyethoxy)-2-[(1-ethoxyethoxy)methyl]cyclopentyl}acetic acid with lead tetraacetate. [ABSTRACT FROM AUTHOR]

A enantioselective tandem transformation, concerning asymmetric allylic decarboxylative addition and cyclization of N-nosylimines with vinylethylene carbonates (VECs), in the presence of [Rh(C2H4)2Cl]2, chiral sulfoxide-N-olefin tridentate ligand has been developed. The reaction of VECs with various substituted N-nosylimines proceeded smoothly under mild conditions, providing highly functionalized oxazolidine frameworks in good to high yields with good to excellent enantioselectivity. [ABSTRACT FROM AUTHOR]

Using our recent relevant results, this account shows the featured reactivities of two‐molecule photoredox systems compared to one‐molecule photoredox systems. The low efficiency of electron transfer processes, such as photoinduced and back‐electron transfer, in the two‐molecule photoredox system, furnishes unique products through different pathways. The facile replacement of photoredox catalysts with appropriate oxidation/reduction potentials in this system provides valuable insights into photoredox reactions. [ABSTRACT FROM AUTHOR]

An efficient method for the oxidative decarboxylation of arylacetic acids and arylacetic esters using trans-5-hydroperoxy-3,5-dimethyl-1,2-dioxolane-3-yl ethaneperoxate in combination with KOH as base is reported. The decarboxylation of carboxylic acids and their derivatives was efficiently achieved with singlet molecular oxygen. Singlet molecular oxygen was produced in situ from the fragmentation of the trans-5-hydroperoxy-3,5-dimethyl-1,2-dioxolane-3-yl ethaneperoxate in the presence of KOH, and it has been explored as an effective oxidant for oxidative decarboxylation of arylacetic acids. Further investigation showed that the reaction also permits the synthesis of aromatic ketones by oxidative decarboxylation of arylacetic esters. An efficient method for the oxidative decarboxylation of arylacetic acids and arylacetic esters is reported.The decarboxylation of carboxylic acids and their derivatives were efficiently achieved with singlet molecular oxygen. Singlet molecular oxygen was produced insitu from fragmentation of the trans-5-hydroperoxy-3,5-dimethyl-1,2- dioxolane-3-yl ethaneperoxate in the presence of KOH, and it has been explored as an effective oxidant for oxidative decarboxylation of arylacetic acids and arylacetic esters. [ABSTRACT FROM AUTHOR]

The use of Activated Carboxylic Acids (ACAs) allows the time‐controlled operation of dissipative chemical systems based on the acid‐base reaction by providing both the stimulus that temporarily drives a physicochemical change and, subsequently, the counter‐stimulus with a single reagent addition. However, their application is inherently limited to acid‐sensitive systems. To overcome this limitation, we herein develop a straightforward device for the transduction of the acid‐base stimuli delivered by an ACA into a voltage signal that, in turn, is used to control voltage‐sensitive circuits that are not pH‐responsive by themselves. The signal transductor can be easily assembled from common laboratory equipment and employs aqueous solutions of readily available chemicals. Furthermore, the operator can simply and intuitively tune the amplitude of the voltage signal, as well as its duration and offset by varying the concentration of the chemical species involved in the transduction process. [ABSTRACT FROM AUTHOR]

A convenient and versatile approach to important 1‐azaspirocyclic systems relevant to medicinal chemistry and natural products is reported herein. The main strategy relies on a reductive decarboxylative cyclization of redox‐active esters which can be rapidly assembled from abundant cyclic azaacids and tailored acceptor sidechains, with a focus on alkyne acceptors enabling the generation of useful exo‐alkene moieties. Diastereoconvergent variants were studied and could be achieved either through remote stereocontrol or conformational restriction in bicyclic carbamate substrates. Two sets of metal‐free photocatalytic conditions employing inexpensive eosin Y were disclosed and studied experimentally to highlight key mechanistic divergences. [ABSTRACT FROM AUTHOR]

Reported herein is an unprecedented protocol for C(sp3)‐phosphinylation. With 1 mol % 4CzIPN (1,2,3,5‐tetrakis(carbazol‐9‐yl)‐4,6‐dicyanobenzene) as the catalyst, the visible light induced reaction of redox‐active esters of aliphatic carboxylic acids with dimethyl arylphosphonites or diethyl alkylphosphonites at room temperature provides the corresponding decarboxylative phosphinylation products in satisfactory yields. The protocol exhibits broad substrate scope and wide functional‐group compatibility, enabling the late‐stage modification of complex molecules and rapid synthesis of bioactive phosphinic acids such as glutamine synthetase phosphinothricin and a kynureninase inhibitor. A radical‐polar crossover mechanism involving the formation and subsequent oxidation of phosphoranyl radicals followed by nucleophilic demethylation (or deethylation) is proposed. [ABSTRACT FROM AUTHOR]

Reported herein is an unprecedented protocol for C(sp3)‐phosphinylation. With 1 mol % 4CzIPN (1,2,3,5‐tetrakis(carbazol‐9‐yl)‐4,6‐dicyanobenzene) as the catalyst, the visible light induced reaction of redox‐active esters of aliphatic carboxylic acids with dimethyl arylphosphonites or diethyl alkylphosphonites at room temperature provides the corresponding decarboxylative phosphinylation products in satisfactory yields. The protocol exhibits broad substrate scope and wide functional‐group compatibility, enabling the late‐stage modification of complex molecules and rapid synthesis of bioactive phosphinic acids such as glutamine synthetase phosphinothricin and a kynureninase inhibitor. A radical‐polar crossover mechanism involving the formation and subsequent oxidation of phosphoranyl radicals followed by nucleophilic demethylation (or deethylation) is proposed. [ABSTRACT FROM AUTHOR]

The development of selective extraction protocols for Cannabis-inflorescence constituents is still a significant challenge. The characteristic Cannabis fragrance can be mainly ascribed to monoterpenes, sesquiterpenes and oxygenated terpenoids. This work investigates the entrapment of Cannabis terpenes in olive oil from inflorescences via stripping under mild vacuum during the rapid microwave-assisted decarboxylation of cannabinoids (MW, 120 °C, 30 min) and after subsequent extraction of cannabinoids (60 and 100 °C). The profiles of the volatiles collected in the oil samples before and after the extraction step were evaluated using static headspace solid-phase microextraction (HS-SPME), followed by gas chromatography coupled to mass spectrometry (GC-MS). Between the three fractions obtained, the first shows the highest volatile content (~37,400 mg/kg oil), with α-pinene, β-pinene, β-myrcene, limonene and trans-β-caryophyllene as the main components. The MW-assisted extraction at 60 and 100 °C of inflorescences using the collected oil fractions allowed an increase of 70% and 86% of total terpene content, respectively. Considering the initial terpene amount of 91,324.7 ± 2774.4 mg/kg dry inflorescences, the percentage of recovery after decarboxylation was close to 58% (mainly monoterpenes), while it reached nearly 100% (including sesquiterpenes) after extraction. The selective and efficient extraction of volatile compounds, while avoiding direct contact between the matrix and extraction solvents, paves the way for specific applications in various aromatic plants. In this context, aromatized extracts can be employed to create innovative Cannabis-based products within the hemp processing industry, as well as in perfumery, cosmetics, dietary supplements, food, and the pharmaceutical industry. [ABSTRACT FROM AUTHOR]

This article examines the changes in leaf respiration during the night, specifically focusing on the decrease in leaf respiratory O2-uptake and CO2-efflux. The authors analyze data from various studies and find that these decreases indicate a decrease in leaf mitochondrial electron transport and ATP demand. The article emphasizes the need for further research to understand the underlying mechanisms and species-specific differences in nocturnal changes in leaf respiration. The authors also discuss the implications of changes in the respiratory quotient (RQ), suggesting that the relative composition of respiratory substrates may shift during the early hours of the dark period. They highlight the importance of studying factors that affect RQ, such as substrate composition and demand for respiratory intermediates. Overall, this information is valuable for understanding the relationship between environmental and metabolic regulation of respiration and its impact on carbon uptake. [Extracted from the article]

In this study, porous amorphous SiO2−Al2O3 (ASA(Si/Al=x)) with different Si/Al ratios was synthesized by gel‐gel method, and used to catalyze green renewable energy source γ‐valerolactone (GVL) to butene. Research indicated that all prepared catalysts had large amounts of disordered mesoporous with the pore size in range of 2–13 nm. For the optimal ASA(Si/Al=20) catalyst, its specific surface area is 430.20 m2 g−l and pore size is about 8.13 nm. Due to the presence of suitable Al species, ASA(Si/Al=20) has the largest Brønsted/Lewis ratio and 0.5554 mmol g−1 weak acid site content. Under the optimized reaction conditions, 90 % butene yield can be obtained in 180 min at 300 °C. In addition, the regeneration performance of the ASA(Si/Al=20) catalyst is also satisfactory, and the yield of butene can be above 60 % after 5th cycles. After activation, the spent catalyst can be regenerated, and about 78 % butene yield can be also obtained. [ABSTRACT FROM AUTHOR]

Sulfilimines, the aza‐variants of sulfoxides, are key structural motifs in natural products, pharmaceuticals, and agrochemicals; and sulfilimine synthesis is therefore important in organic chemistry. However, methods for radical sulfilimination remain elusive, and as a result, the structural diversity of currently available sulfilimines is limited. Herein, we report the first protocol for decarboxylative radical sulfilimination reactions between sulfenamides and N‐hydroxyphthalimide esters of primary, secondary, and tertiary alkyl carboxylic acids, which were achieved via a combination of photoredox, copper, and Brønsted base catalysis. This novel protocol provided a wide variety of sulfilimines, in addition to serving as an efficient route for the synthesis of S‐alkyl/S‐aryl homocysteine sulfilimines and S‐(4‐methylphenyl) homocysteine sulfoximine. Moreover, it could be used for late‐stage introduction of a sulfilimine group into structurally complex molecules, thereby avoiding the need to preserve labile organosulfur moieties through multistep synthetic sequences. A mechanism involving photocatalytic substrate transformation and copper‐mediated C(sp3)−S bond formation is proposed. [ABSTRACT FROM AUTHOR]

Sulfilimines, the aza‐variants of sulfoxides, are key structural motifs in natural products, pharmaceuticals, and agrochemicals; and sulfilimine synthesis is therefore important in organic chemistry. However, methods for radical sulfilimination remain elusive, and as a result, the structural diversity of currently available sulfilimines is limited. Herein, we report the first protocol for decarboxylative radical sulfilimination reactions between sulfenamides and N‐hydroxyphthalimide esters of primary, secondary, and tertiary alkyl carboxylic acids, which were achieved via a combination of photoredox, copper, and Brønsted base catalysis. This novel protocol provided a wide variety of sulfilimines, in addition to serving as an efficient route for the synthesis of S‐alkyl/S‐aryl homocysteine sulfilimines and S‐(4‐methylphenyl) homocysteine sulfoximine. Moreover, it could be used for late‐stage introduction of a sulfilimine group into structurally complex molecules, thereby avoiding the need to preserve labile organosulfur moieties through multistep synthetic sequences. A mechanism involving photocatalytic substrate transformation and copper‐mediated C(sp3)−S bond formation is proposed. [ABSTRACT FROM AUTHOR]

This article presents a study on the synthesis of primary benzylamines, which are important in medicinal chemistry. The researchers used a photoredox-catalyzed decarboxylative coupling method with aryl halides and glycine derivatives to create these molecules. They discuss the reaction mechanism and provide experimental results, including different reaction conditions and yields. This research contributes to the development of new synthetic procedures for primary benzylamine scaffolds, which could lead to the discovery of new functional molecules. Additionally, the study explores the decarboxylative aminomethylation of aryl bromides with glycine derivatives, testing various reaction conditions and catalysts to optimize product yield. The researchers found that electron-deficient aryl bromides reacted well, and the reaction was applicable to other heteroarenes. They also investigated the impact of different protecting groups on the nitrogen atom. Overall, this study offers an efficient method for synthesizing aminomethylated compounds, which may have potential applications in drug discovery. [Extracted from the article]

This article explores the use of iron catalysts in the production of urethanes, which are widely used in organic synthesis and medicinal chemistry. The traditional method of producing urethanes involves hazardous chemicals, so researchers have been investigating alternative routes. The article discusses a new method that uses iron catalysts in a photochemical process to convert oxamic acids into isocyanates, which can then react with alcohols to form urethanes. This method shows promise in providing a safer and more environmentally friendly approach to synthesizing urethanes. Additionally, the article discusses the application of graph theory in various fields, such as social networks, biology, and transportation. It explains how graphs can be used to represent and analyze complex systems, allowing researchers to gain insights and make predictions. The authors highlight the importance of graph theory in understanding the interconnectedness of different elements in a system and its potential for future research and applications. [Extracted from the article]

This document discusses a study on the effects of electron-donor (ED) and counter-cation in the photoinduced generation of aryl radicals using two-molecule photoredox catalysts. The researchers focused on the use of arylboronic acids, arylboronic acid esters, and benzoic acids as substrates for generating aryl radicals. They found that the choice of ED and counter-cation had a significant impact on the yield of the desired products. The research provides valuable insights into factors affecting aryl radical generation and could contribute to the development of more efficient synthetic methods. [Extracted from the article]

The application of deuterated compounds is increasingly expanding across various fields, making the development of novel deuterium labeling techniques for obtaining deuterated compounds a burgeoning research focus. Carboxylic acids and their derivatives are widely utilized as cost‐effective and readily available materials for obtaining deuterated compounds due to their stable properties. This article presents a comprehensive and concise summary of the research progress in decarboxylative deuteration reactions over the past 20 years. [ABSTRACT FROM AUTHOR]

A visible-light-promoted formal [2 + 2 + 1] cyclization of N-aryl glycines with quinoxalin-2(1H)-ones to synthesize tetrahydroimidazo[1,5-a]quinoxalin-4(5H)-ones have been developed. The protocol features operational simplicity, mild reaction conditions with blue LED light employing Ru(bpy)3Cl2. 6H2O as a photoredox catalyst, a combination of O2 from air and Cu(OAc)2 as the oxidant and broad substrate applicability. [ABSTRACT FROM AUTHOR]

Biodiesel has emerged as a possible replacement for fossil-based fuels, particularly in the transportation industry. Because of its high oxygen content, it has several limitations including high viscosity, pour point and cloud point. Converting biodiesel to hydrocarbons is one method of improving the poor flow properties. In this study, Reactive Force Field (ReaxFF) molecular dynamics was used to study the decarboxylation of methyl palmitate on α-NiMoO4, β-NiMoO4 and Ni3Mo catalysts. The results show that the reactions are faster in the presence of α-NiMoO4 and β-NiMoO4, and the number of stable products, carbon dioxide and ethene was higher than they were without the catalyst. With Ni3Mo catalyst, there is rapid initial formation of CO2 and C2H4 until a maximum is reached followed by a decrease in their quantity. The C2H4 was found to decompose to C2H2 and H2 while CO2 was reduced to CO. All reactions were found to follow first-order kinetics, from which the activation energies (Ea) were determined. The Ea drops from 36.89 kcal/mol for uncatalyzed reaction to 25.66, 19.34 and 11.69 kcal/mol for the α-NiMoO4, β-NiMoO4 and Ni3Mo catalysed reactions, respectively. The Ni3Mo catalysed system's Ea was also closest to the experimentally reported value of 10.11 kcal/mol [1]. [ABSTRACT FROM AUTHOR]

α‐Sulfinyl esters can be readily prepared through thiol substitution of α‐bromo esters followed by oxidation to the sulfoxide. Enzymatic resolution with lipoprotein lipase provides both the unreacted esters and corresponding α‐sulfinyl carboxylic acids in high yields and enantiomeric ratios. Subsequent decarboxylative halogenation, dihalogenation, trihalogenation and cross‐coupling gives rise to functionalized sulfoxides. The method has been applied to the asymmetric synthesis of a potent inhibitor of 15‐prostaglandin dehydrogenase. [ABSTRACT FROM AUTHOR]

Simple Summary: Cancer represents unrestricted growth with the removal of conventional brakes that control growth under normal conditions. This requires novel mechanisms to provide metabolic energy to fuel the rapid growth and also macromolecules to support cell renewal. This unique need in cancer cells is accomplished by an efficient interplay between selective nutrient transporters and the reprogramming of cellular metabolism that modifies specific catabolic and anabolic pathways. These modified biochemical pathways generate certain metabolites that are seen at high levels only in cancer cells, and reroute signaling cascades, alter gene expression profiles, and exert biological effects in support of the growth and proliferation of cancer cells. A clear understanding of the metabolic signature that is unique to cancer cells is necessary not only to appreciate how the unrestricted growth is accomplished in cancer but also to exploit these cancer-cell-specific nutrient transporters and metabolic pathways as drug targets to develop new anticancer therapeutics. Aerobic glycolysis in cancer cells, originally observed by Warburg 100 years ago, which involves the production of lactate as the end product of glucose breakdown even in the presence of adequate oxygen, is the foundation for the current interest in the cancer-cell-specific reprograming of metabolic pathways. The renewed interest in cancer cell metabolism has now gone well beyond the original Warburg effect related to glycolysis to other metabolic pathways that include amino acid metabolism, one-carbon metabolism, the pentose phosphate pathway, nucleotide synthesis, antioxidant machinery, etc. Since glucose and amino acids constitute the primary nutrients that fuel the altered metabolic pathways in cancer cells, the transporters that mediate the transfer of these nutrients and their metabolites not only across the plasma membrane but also across the mitochondrial and lysosomal membranes have become an integral component of the expansion of the Warburg effect. In this review, we focus on the interplay between these transporters and metabolic pathways that facilitates metabolic reprogramming, which has become a hallmark of cancer cells. The beneficial outcome of this recent understanding of the unique metabolic signature surrounding the Warburg effect is the identification of novel drug targets for the development of a new generation of therapeutics to treat cancer. [ABSTRACT FROM AUTHOR]

Ten Gouda cheese wheels with an age of 31 weeks from six different batch productions were affected by a crack defect and displayed an unpleasant off-flavor. To unravel the causes of these defects, the concentrations of free amino acids, other organic acids, volatile organic compounds, and biogenic amines were quantified in zones around the cracks and in zones without cracks, and compared with those of similar Gouda cheeses without crack defect. The Gouda cheeses with cracks had a significantly different metabolome. The production of the non-proteinogenic amino acid γ-aminobutyric acid (GABA) could be unraveled as the key mechanism leading to crack formation, although the production of the biogenic amines cadaverine and putrescine contributed as well. High-throughput amplicon sequencing of the full-length 16S rRNA gene based on whole-community DNA revealed the presence of Loigolactobacillus rennini and Tetragenococcus halophilus as most abundant non-starter lactic acid bacteria in the zones with cracks. Shotgun metagenomic sequencing allowed to obtain a metagenome-assembled genome of both Loil. rennini and T. halophilus. However, only Loil. rennini contained genes necessary for the production of GABA, cadaverine, and putrescine. Metagenetics further revealed the brine and the rennet used during cheese manufacturing as the most plausible inoculation sources of both Loil. rennini and T. halophilus. [ABSTRACT FROM AUTHOR]

Trifluoroacetates are the most abundant and accessible sources of trifluoromethyl groups, which are key components in pharmaceuticals and agrochemicals. The generation of trifluoromethyl reactive radicals from trifluoroacetates requires their decarboxylation, which is hampered by their high oxidation potential. This constitutes a major challenge for redox‐based methods, because of the need to pair the redox potentials with trifluoroacetate. Here we report a strategy based on iron photocatalysis to promote the direct photodecarboxylation of trifluoroacetates that displays reactivity features that escape from redox limitations. Our synthetic design has enabled the use of trifluoroacetates for the trifluoromethylation of more easily oxidizable organic substrates, offering new opportunities for late‐stage derivatization campaigns using chemical feedstocks, Earth‐abundant catalysts, and visible‐light. [ABSTRACT FROM AUTHOR]

A photocatalytic domain of doubly decarboxylative Csp2−Csp2 cross coupling reaction is disclosed. Merging iridium and palladium photocatalysis manifested carbon‐carbon bonds in a tandem dual‐radical pathway. Present catalytic platform efficiently cross‐coupled α, β‐unsaturated acids and α‐keto acids to afford a variety of α, β‐unsaturated ketones with excellent (E)‐selectivity and functional group tolerance. Mechanistically, photocatalyst implicated through reductive quenching cycle whereas cross coupling proceeded over one electron oxidative pallado‐cycle. [ABSTRACT FROM AUTHOR]

Trifluoroacetates are the most abundant and accessible sources of trifluoromethyl groups, which are key components in pharmaceuticals and agrochemicals. The generation of trifluoromethyl reactive radicals from trifluoroacetates requires their decarboxylation, which is hampered by their high oxidation potential. This constitutes a major challenge for redox‐based methods, because of the need to pair the redox potentials with trifluoroacetate. Here we report a strategy based on iron photocatalysis to promote the direct photodecarboxylation of trifluoroacetates that displays reactivity features that escape from redox limitations. Our synthetic design has enabled the use of trifluoroacetates for the trifluoromethylation of more easily oxidizable organic substrates, offering new opportunities for late‐stage derivatization campaigns using chemical feedstocks, Earth‐abundant catalysts, and visible‐light. [ABSTRACT FROM AUTHOR]

The controlled grafting of polymers from small‐ and macro‐molecular substrates is an essential process for many advanced polymer applications. This usually requires the pre‐functionalisation of substrates with an appropriate functional group, such as a RAFT agent or ATRP initiator, which requires additional synthetic steps. In this paper, we describe the direct grafting of RAFT polymers from carboxylate containing small molecules and polymers via photochemical radical decarboxylation. This method utilises the innate functional groups present in the substrates, and achieves efficient polymer initiation in a single step with excellent control of molecular weight and dispersity. [ABSTRACT FROM AUTHOR]

The controlled grafting of polymers from small‐ and macro‐molecular substrates is an essential process for many advanced polymer applications. This usually requires the pre‐functionalisation of substrates with an appropriate functional group, such as a RAFT agent or ATRP initiator, which requires additional synthetic steps. In this paper, we describe the direct grafting of RAFT polymers from carboxylate containing small molecules and polymers via photochemical radical decarboxylation. This method utilises the innate functional groups present in the substrates, and achieves efficient polymer initiation in a single step with excellent control of molecular weight and dispersity. [ABSTRACT FROM AUTHOR]