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ABSTRACT The new type of the four‐component tandem Knoevenagel–Michael reaction was discovered: the transformation of arylaldehydes, N,N′‐dimethylbarbituric acid, malononitrile, and morpholine in alcohols and other organic solvents without any other additives at ambient temperature resulted in the selective formation of a new substituted unsymmetrical ionic scaffold with two pharmacology‐active heterocyclic rings. This new four‐component reaction is a simple and efficient route to a previously unknown substituted ionic unsymmetrical scaffold containing N,N′‐dimethylbarbituric acid and morpholine. These ionic scaffolds are promising for various biomedical applications, for example, as anticonvulsants and anti‐inflammatory drugs, as well as anti‐AIDS agents. In this research, we also accomplished the efficient cyclization of morpholin‐4‐ium 5‐(2,2‐dicya‐no‐1‐arylethyl)‐1,3‐dimethyl‐2,6‐di‐oxo‐1,2,3,6‐tetrahydro‐pyrimidin‐4‐olates by the action of NBS–NaOAc system, with the formation of 5,7‐dimethyl‐4,6,8‐trioxo‐2‐aryl‐5,7‐diazaspiro[2.5]octane‐1,1‐dicarbonitriles in 83%–98% yields. In the final stage of our research, direct one‐pot multicomponent transformation of benzaldehydes, N,N′‐dimethylbarbituric acid, and malononitrile into spirobarbituric cyclopropanes was accomplished in 75%–97% yields. The spiro‐barbituric cyclopropanes are potentially active as remedies against various inflammatory, infectious, immunological, or malignant diseases. [ABSTRACT FROM AUTHOR]

We report an efficient protocol for oxidation of primary/secondary benzyl alcohols and benzylamines to produce corresponding aldehydes or ketones. Our unified method involves the use of commercially available (diethylamino)sulfur trifluoride (DAST) as a reagent combined with DMSO as solvent and oxidant. The reaction provided corresponding carbonyl compounds in good to excellent yields with high purity and in short reaction times. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Transition‐metal‐catalyzed asymmetric alkylation of aldehydes represents a straightforward strategy for the synthesis of chiral secondary alcohols. However, efficient methods using organoborons as coupling reagents are rare. Herein, we report a highly enantioselective nickel‐catalyzed alkylation reaction of aldehydes, using readily available alkylborons as nucleophiles. A wide variety of chiral secondary alcohols were prepared from commercially available aldehydes with high yields. The key to the excellent enantioselectivity and chemoselectivity was the employment of a bulky C2‐symmetric chiral NHC ligand. This protocol features excellent enantiocontrol, mild conditions, and good functional group compatibility. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Transition‐metal‐catalyzed asymmetric alkylation of aldehydes represents a straightforward strategy for the synthesis of chiral secondary alcohols. However, efficient methods using organoborons as coupling reagents are rare. Herein, we report a highly enantioselective nickel‐catalyzed alkylation reaction of aldehydes, using readily available alkylborons as nucleophiles. A wide variety of chiral secondary alcohols were prepared from commercially available aldehydes with high yields. The key to the excellent enantioselectivity and chemoselectivity was the employment of a bulky C2‐symmetric chiral NHC ligand. This protocol features excellent enantiocontrol, mild conditions, and good functional group compatibility. [ABSTRACT FROM AUTHOR]

A one-step, on-tissue chemical derivatisation method for MALDI mass spectrometry imaging was found to improve the detectability of aldehydes and ketones by charge-tagging. The developed reactive matrices, containing a UV-chromophore, ionisable moiety and hydrazide group, showed an equal or higher detection efficiency than Girard's reagent P, enabling improved imaging of brain metabolites without the need for additional co-matrices. [ABSTRACT FROM AUTHOR]

The Petasis reaction is a multicomponent reaction of aldehydes, amines and organoboron reagents and is a useful method for the construction of substituted amines. Despite the significant advancement of the Petasis reaction since its invention in 1993, strategies for asymmetric and non‐directed Petasis reactions remain limited. To date, there are very few catalytic asymmetric Petasis reactions and almost all asymmetric reports employ a chiral auxiliary. Likewise, the aldehyde component often requires a directing group, ultimately limiting the reaction's scope. In this Concept, key methods for asymmetric and non‐directed Petasis reactions are discussed, focusing on how these conceptual advances can be applied to solve long‐standing gaps in the Petasis literature. [ABSTRACT FROM AUTHOR]

A new eco-friendly method for the synthesis of mono- and multifunctional organosulfur compounds, based on the process between ynals and thiols, catalyzed by bulky N-heterocyclic carbene (NHC), was designed and optimized. The proposed organocatalytic approach allows the straightforward formation of a broad range of thioesters and sulfenyl-substituted aldehydes in yields above 86%, in mild and metal-free conditions. In this study, thirty-six sulfur-based derivatives were obtained and characterized by spectroscopic methods. [ABSTRACT FROM AUTHOR]

Cyano and amide are important functionalities in medicinal chemistry, and organic chemistry transformations. We have devised a new, safe, and easy method for the synthesis of cyano and further amide using aldehyde via copper-mediated cyanation and amidation with ammonium acetate/iodine in DMF in a time-dependent manner. This approach efficiently converts aryl/alkyl/hetero aldehydes into their corresponding cyano which can be isolated after 3 h and/or if continued for 24 h then in-situ transformed into amide derivatives. Herein cupric acetate plays the role of coordinator, ammonium acetate is the nitrogen source, while DMF serves as a carbon source. We did easy and safe cyanation to explore the synthesis of varieties of cyano in 69–86% yields and respective amide derivatives in 58–75% yields. Thus, this process can serve the dual advantage in the synthesis of cyano and amides bioactive scaffold using respective aldehyde. [ABSTRACT FROM AUTHOR]

Objective: The objective of this study is to determine the associations of protein‐specific anti–malondialdehyde‐acetaldehyde (MAA) antibodies with prevalent and incident rheumatoid arthritis–interstitial lung disease (RA‐ILD). Methods: Within a multicenter, prospective cohort of US veterans with RA, RA‐ILD was validated by medical record review of clinical diagnoses, chest imaging, and pathology. Serum antibodies to MAA‐albumin, MAA‐collagen, MAA‐fibrinogen, and MAA‐vimentin (IgA, IgM, and IgG) were measured by a standardized enzyme‐linked immunosorbent assay. Associations of anti‐MAA antibodies with prevalent and incident RA‐ILD were assessed using multivariable regression models adjusting for established RA‐ILD risk factors. Results: Among 2,739 participants with RA (88% male, mean age of 64 years), there were 114 with prevalent and 136 with incident RA‐ILD (average time to diagnosis: 6.6 years). Higher IgM anti–MAA‐collagen (per 1 SD: adjusted odds ratio [aOR] 1.28, 95% confidence interval [CI] 1.02–1.61), IgA anti–MAA‐fibrinogen (aOR 1.48, 95% CI 1.14–1.92), and IgA (aOR 1.78, 95% CI 1.34–2.37) and IgG (aOR 1.48, 95% CI 1.14–1.92) anti–MAA‐vimentin antibodies were associated with prevalent RA‐ILD. In incident analyses, higher IgA (per one SD: adjusted hazards ratio [aHR] 1.40, 95% CI 1.11–1.76) and IgM (aHR 1.29, 95% CI 1.04–1.60) anti–MAA‐albumin antibody concentrations were associated with increased ILD risk. Participants with IgA (aHR 2.13, 95% CI 1.16–3.90) or IgM (aHR 1.98, 95% CI 1.08–3.64) anti–MAA‐albumin antibody concentrations in the highest quartile had an approximately two‐fold increased risk of incident RA‐ILD. Across all isotypes, anti–MAA‐fibrinogen, anti–MAA‐collagen, and anti–MAA‐vimentin antibodies were not significantly associated with incident RA‐ILD. Conclusion: Protein‐specific anti‐MAA antibodies to collagen, fibrinogen, and vimentin were associated with prevalent RA‐ILD. IgA and IgM anti–MAA‐albumin antibodies were associated with a higher risk of incident RA‐ILD. These findings suggest that MAA modifications and resultant immune responses may contribute to RA‐ILD pathogenesis. [ABSTRACT FROM AUTHOR]

Summary: This study investigated the effects of reducing sugars and protein‐to‐sugar ratios on generating volatile compounds from nutritional yeast hydrolysates after Maillard reaction. Nutritional yeast extract (NYE) was cleaved using Flavourzyme® at an enzyme‐to‐substrate ratio of 0.5% w/w, followed by heat treatment with varying concentrations of reducing sugars (i.e., hexoses: glucose and fructose and pentoses: xylose and ribose). The results showed that pentoses generate higher numbers and concentrations of volatiles than hexoses, especially furans, Strecker aldehydes, and sulphur‐containing compounds such as dimethyl disulphide. However, hexoses produced higher concentrations of pyrazines. Strecker aldehydes and pyrazines served as key aroma‐active compounds in meat aroma. Likewise, sulphur‐containing compounds played an important role in meat aroma due to their low detection threshold. The results showed that reducing sugars significantly impacts the volatile profile of NYE, potentially influencing the formation of meaty aroma compounds. These findings demonstrate the potential of MRPs to enhance meaty flavours due to the presence of volatile compounds with characteristics of cooked meat. [ABSTRACT FROM AUTHOR]

Simple, environmentally benign and metal free one pot strategy has been used for the synthesis of 4-iodo-3-phenylbenzo[b][1,6]naphthyridine from O-alkynylquinolinyl aldehydes with tert-butyl amine and iodine through imine formation in good to excellent yield at room temperature in aerobic and mild conditions. The beauty of this reaction is the imine formation and cyclization in the same reaction pot. Due to presence of iodine in product, it can be useful for further reaction and can be valuable synthon for new organic compounds. [ABSTRACT FROM AUTHOR]

Hierarchical Co3O4/triple-shelled carbon nitride (Co3O4/TSCN) composite nanocapsules were designed via a multi-step procedure in a controlled manner as a solar-light-driven photocatalyst based Z-scheme system for selective aerobic photooxidation of alcohols (primary and secondary aliphatic and benzylic) to corresponding aldehydes/ or ketones in green media. The structure of the as-prepared photocatalyst was characterized by a series of measurement techniques including FT-IR, XRD, BET, TEM, FE-SEM, EDX, EDX-mapping, TGA, UV–vis DRS, and ICP-OES. The hierarchical Co3O4/TSCN composite nanocapsules demonstrated superior photocatalytic activity in selective aerobic oxidation of alcohols under solar light irradiation in comparison to pure TSCN and Co3O4 NPs. The shell number of the composite nanocapsules and the formation of the hierarchical Co3O4/TSCN Z-scheme photocatalyst can significantly affect the photocatalytic activity. The results indicate the efficient electron transfer, relatively high specific surface area, high donor density, and low band gap as well as the coexistence of micro-, meso- and macropores and also nano-sized crystalline structure (from 1.2 to 95 nm) in heterojunction composite. This novel photocatalytic system kept relatively high catalytic activity after five recycle runs under the same reaction conditions. [ABSTRACT FROM AUTHOR]

The enantiodivergent synthesis of syn‐Michael adducts can be easily achieved by switching the terminal proline in dipeptidic proline‐thiourea catalysts. In this study, a dipeptidic proline‐derived thiourea organocatalyst was rationally designed and facilely prepared from dipeptidic proline, a chiral diamine as a linker, and isothiocyanate. This asymmetric bifunctional catalyst for Michael addition between aldehydes and nitroolefins provided chiral 4‐nitro aldehyde adducts with yields of up to 99 %, 92 : 8 syn‐diastereoselectivity, and 97 % enantiomeric excess at room temperature. [ABSTRACT FROM AUTHOR]

SUMMARY Among the three active aldehyde oxidases in Arabidopsis thaliana leaves (AAO1‐3), AAO3, which catalyzes the oxidation of abscisic‐aldehyde to abscisic‐acid, was shown recently to function as a reactive aldehyde detoxifier. Notably, aao2KO mutants exhibited less senescence symptoms and lower aldehyde accumulation, such as acrolein, benzaldehyde, and 4‐hydroxyl‐2‐nonenal (HNE) than in wild‐type leaves exposed to UV‐C or Rose‐Bengal. The effect of AAO2 expression absence on aldehyde detoxification by AAO3 and/or AAO1 was studied by comparing the response of wild‐type plants to the response of single‐functioning aao1 mutant (aao1S), aao2KO mutants, and single‐functioning aao3 mutants (aao3Ss). Notably, aao3Ss exhibited similar aldehyde accumulation and chlorophyll content to aao2KO treated with UV‐C or Rose‐Bengal. In contrast, wild‐type and aao1S exhibited higher aldehyde accumulation that resulted in lower remaining chlorophyll than in aao2KO leaves, indicating that the absence of active AAO2 enhanced AAO3 detoxification activity in aao2KO mutants. In support of this notion, employing abscisic‐aldehyde as a specific substrate marker for AAO3 activity revealed enhanced AAO3 activity in aao2KO and aao3Ss leaves compared to wild‐type treated with UV‐C or Rose‐Bengal. The similar abscisic‐acid level accumulated in leaves of unstressed or stressed genotypes indicates that aldehyde detoxification by AAO3 is the cause for better stress resistance in aao2KO mutants. Employing the sulfuration process (known to activate aldehyde oxidases) in wild‐type, aao2KO, and molybdenum‐cofactor sulfurase (aba3‐1) mutant plants revealed that the active AAO2 in WT employs sulfuration processes essential for AAO3 activity level, resulting in the lower AAO3 activity in WT than AAO3 activity in aao2KO. [ABSTRACT FROM AUTHOR]

One‐pot synthetic procedures allow multiple chemical transformations circumventing the isolation of intermediates and thus saving time, energy and feedstocks. Within the scope of one‐pot processes, cascade, domino, or tandem procedures are even more efficient, as multiple reactions can occur in parallel. Hydroformylation is an industrially relevant reaction particularly suitable for this kind of methodology, as the primary products (aldehydes) are usually converted into compounds containing other functionalities. In addition to examples of transformations of the substrate before the hydroformylation step or the transformation of the aldehyde into other functionalities, we highlight a novel approach, in which an additional functionalization takes place in a remote site of the substrate molecule, along with the hydroformylation of the carbon‐carbon double bond. [ABSTRACT FROM AUTHOR]

Comprehensive Summary Catalytic methylative coupling of internal alkynes and aldehydes/aldimines through regioselective oxidative cyclization promoted by a phosphine–Co complex is presented. Such process constitutes an unprecedented and unique approach for Co‐catalyzed generation of metallacycles that reversed inherent regiochemical biases to furnish a wide range of allylic alcohols and allylic amides bearing a tetrasubstituted alkene in up to 98% yield with high regioselectivity, representing a novel and general strategy for reversal of substrate‐controlled regioselectivity in metal‐catalyzed oxidative cyclization. [ABSTRACT FROM AUTHOR]

We studied the reaction of N‐alkyl(aryl)pyrazoles with silylformamidine 1 that exists in an equilibrium with its carbene form via migration of the trimethylsilyl group from the carbon to nitrogen atom. The carbene insertion proceeded at the C−H group in 5th position. N‐alkyl(aryl)pyrazoles featuring substituents such as Br, CN and NO2 group reacted readily affording the corresponding aminals. This approach allowed us to synthesize pyrazole dialdehyde and phosphine featuring a vicinal aldehyde group. The reaction does not require any catalyst. The insertion position was unambiguously confirmed by X‐ray analysis of an aminal and a set of derivatives. Aminals hydrolysis afforded the corresponding pyrazole carbaldehydes. Methanolysis of the aminals gave N‐methylimines of the pyrazolecarbaldehydes. Highly acidic nitro pyrazole instead of the insertion underwent silylation in 5th position. [ABSTRACT FROM AUTHOR]

A phthalimide or 3‐formylindole functionality was incorporated into a tris(hydroxymethyl)ethane (THME) scaffold, and the resulting compounds were subsequently transformed into phosphoramidites and solid supports. These building blocks were then used to synthesise oligonucleotides containing amine or aldehyde groups at various positions within their sequences. The resulting modified oligonucleotides were further conjugated through either amide bond formation or oxime ligation. These novel building blocks expand the repertoire of phosphoramidites and solid supports available for modifying oligonucleotides. [ABSTRACT FROM AUTHOR]

The first synthesis of chiral cis-2,5-disubstituted pyrrolidine organocatalysts is described. Their application for the enantioselective Michael addition of nitromethane to α,β-unsaturated aldehydes with excellent yield (up to 91%) and enantioselectivity (up to >99% ee) is demonstrated. Another catalytic application for the reaction of 2,4-hexadienal with nitrostyrene is also showcased. [ABSTRACT FROM AUTHOR]

We provide an extensive review of 14 studies (11 independent and three industryfunded) on emissions generated by Electronic Cigarettes (ECs), specifically focusing on the evaluation of carbonyls present in these emissions and emphasizing a meticulous evaluation of their analytical methods and experimental procedures. Since the presence of carbonyl by-products in EC aerosol is concerning, it is important to evaluate the reliability of emission studies quantifying these compounds by verifying their compliance with the following criteria of experimental quality: authors must 1) supply sufficient information on the devices and experimental procedures to allow for potentially reproducing or replicating the experiments, 2) use of appropriate puffing protocols that approach consumer usage as best as possible, 3) use of appropriate analytical methods and 4) usage of blank samples to avoid false positive detection. Outcomes were classified in terms of the fulfilment of these conditions as reliable in seven studies, partially reliable in five studies, and unreliable in two studies. However, only five studies used blank samples and six studies failed the reproducibility criterion. Carbonyl yields were far below their yields in tobacco smoke in all reproducible studies, even in the partially reliable ones, thus supporting the role of ECs (when properly tested and operated) as harm reduction products. This review highlights the necessity to evaluate the quality of laboratory standards in testing EC emissions to achieve an objective assessment of the risk profile of ECs. [ABSTRACT FROM AUTHOR]

A photocatalyzed formal (3+2) cycloaddition has been developed to construct original polysubstituted α‐SCF3 cyclopentanones in a regio‐ and diastereoselective manner. This building block approach leverages trifluoromethylthio alkynes and branched/linear aldehydes, as readily available reaction partners, in consecutive hydrogen atom transfers and C−C bond formations. Difluoromethylthio alkynes are also compatible substrates. Furthermore, the potential for telescoped reaction starting from alcohols instead of aldehydes was demonstrated, as well as process automatization and scale‐up under continuous microflow conditions. This prompted density functional theory (DFT) calculations to support a radical‐mediated cascade process. [ABSTRACT FROM AUTHOR]

We report a copper‐catalyzed reductive aldol addition to aldehydes and ketones, with pinacolborane as stoichiometric reductant, that results in the generation of stereodefined syn‐aldol products. Cyclic, acyclic, fused and spirocyclic aldols bearing contiguous stereocenters are obtained with excellent yields and diastereoselectivities. Moreover, enantioselective reactions could be carried out with cycloalkenones to deliver aldols bearing three contiguous stereocenters and with up to 98 % ee. Computations reveal that the enolborate intermediate undergoes the syn‐aldol reaction via a twist‐boat transition state that is stabilized by non‐classical hydrogen bonding interactions. [ABSTRACT FROM AUTHOR]

Herein, we demonstrate an Oxa‐Diels‐Alder reaction of 3‐trifluoroacetyl‐4‐methyl‐quinolin‐2(1H)‐one with aldehydes in the presence of a base to engineer the functionalized pyrano[3,4‐c]quinolones. This reaction proceeds through an in‐situ generated hetero dendralene intermediate and features perfect stereoselectivity on a wide range of substrates with excellent atom economy. The high electron‐withdrawing nature of CF3‐group is responsible for making the methyl group present in quinolone moiety more acidic to furnish the corresponding hetero dendralene intermediate. [ABSTRACT FROM AUTHOR]

The facile generation of the α‐acyloxy carboxamide radical is hereby reported for the first time, utilizing a photoredox catalyzed reaction of Passerini adducts synthesized using a 4‐formyl‐1,4‐dihydropyridine as the carbonyl component. This radical effectively engages in a Giese reaction with a range of olefins, ultimately leading to the synthesis of novel Passerini‐derived products not previously amenable to direct aldehyde‐based transformations. Consequently, the resulting strategy, developed both in batch and in flow, offers a promising opportunity to expand the chemical space accessible through the Passerini reaction, virtually incorporating “impossible” aldehydes. [ABSTRACT FROM AUTHOR]

N-Substituted 5-(hydroxymethyl)-2-furfuryl amines have been obtained through the reductive amination of 5-hydroxymethylfurfural (HMF) with a variety of primary amines using a non-noble metal catalyst based on monodisperse Co nanoparticles covered by a thin carbon layer. The Co@C catalyst was highly active, selective and stable, allowing us to perform the reductive amination of HMF under very mild reaction conditions (60 °C and 4 bar H2) using ethanol as a green solvent and achieve the corresponding amino-alcohol in yields ranging from 80 to 99%. Moreover, the reaction was extended to other furanic aldehydes with excellent success. Furthermore, in order to synthesize amino-ester derivatives, precursors of ammonium salt-based surfactants, the reductive amination of HMF with methylamine was coupled with the selective esterification of the hydroxymethyl group of the furan ring with fatty acids using lipase CALB (Novozym 435) as a biocatalyst in 2-methyltetrahydrofuran as a green and enzyme compatible solvent, achieving practically total conversion to the corresponding amino-esters. The process was implemented in flow reactors by combining two consecutive fixed bed reactors, achieving a global yield of the amino-ester derivative of 85%, which was maintained over 86 h of operation. [ABSTRACT FROM AUTHOR]

This research article focuses on the pathway for metal‐free unprecedented one‐pot three‐component synthesis of biologically active 3‐pyrazolyl‐thiazolidin‐4‐one derivatives through cyclo‐condensation of aromatic aldehydes, 1H‐pyrazol‐3‐amine and thioglycolic acid in aqueous medium. p‐Toluene sulphonic acid (PTSA), a non‐toxic, cheaper, easily accessible, eco‐benign, organic acid‐catalyst was explored to mediate this reaction. Formation of novel 3‐pyrazolyl‐thiazolidin‐4‐one derivatives, environment‐benign conditions, quick reaction time, excellent functional group acceptance and moderate to high yield of the products are some of the chief advantages of the reaction. Further, this methodology will surely contribute in various fields of synthetic organic methodology, pharmaceutical industry and natural bio‐active product synthesis. [ABSTRACT FROM AUTHOR]

Catalytic enantioselective alkenylation of aldehydes with easily accessible alkenyl halides promoted by a chiral cobalt complex derived from a newly developed tridentate bisoxazolinephosphine is presented. Such processes represent an unprecedented reaction pathway for cobalt catalysis and a general approach that enable rapid construction of highly diversified enantioenriched allylic alcohols containing a 1,1‐, 1,2‐disubstituted and trisubstituted alkene as well as axial stereogenicity in up to 99 % yield and 99 : 1 er without the need of preformation of alkenyl–metal reagents. DFT calculations revealed the origin of enantioselectivity. [ABSTRACT FROM AUTHOR]

During the past decades, N‐heterocyclic carbene (NHC)‐catalyzed reactions have emerged as a versatile tool in synthetic chemistry. In particular, NHC‐catalyzed cross‐coupling reaction has been significantly developed in many respects, including new reaction development and mechanistic investigation. This concept article presents recent advances towards direct cross‐coupling reactions of aldehydes with alkyl halides enabled by NHC organocatalysis. [ABSTRACT FROM AUTHOR]

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The synthesis of volicitin involved the condensation of l -(+)-glutamine with 17(S)-hydroxylinolenoic acid, derived from a Wittig reaction between the C10–C18 phosphonium salt and the C1–C9 aldehyde. The phosphonium salt was prepared through the alkynylation of a (Z)-allylic phosphate with an alkyne derived from (2 S)-but-3-yn-2-ol. The deuterated aldehyde was derived with a 96% deuteration ratio by reduction of the C1–C9 methyl ester with NaBD4 , followed by oxidation. Subsequently, 9- D1-volicitin was synthesized from the monodeuterated aldehyde by using the Wittig reaction and condensation with l -(+)-glutamine. [ABSTRACT FROM AUTHOR]

It has been reported that the modification of immobilized glyoxyl–ficin with aldehyde dextran can promote steric hindrances that greatly reduce the activity of the immobilized protease against hemoglobin, while the protease still maintained a reasonable level of activity against casein. In this paper, we studied if this effect may be different depending on the amount of ficin loaded on the support. For this purpose, both the moderately loaded and the overloaded glyoxyl–ficin biocatalysts were prepared and modified with aldehyde dextran. While the moderately loaded biocatalyst had a significantly reduced activity, mainly against hemoglobin, the activity of the overloaded biocatalyst was almost maintained. This suggests that aldehyde dextran was able to modify areas of the moderately loaded enzyme that were not available when the enzyme was overloaded. This modification promoted a significant increase in biocatalyst stability for both biocatalysts, but the stability was higher for the overloaded biocatalyst (perhaps due to a combination of inter- and intramolecular crosslinking). [ABSTRACT FROM AUTHOR]

The present work details the synthesis of several intriguing nitrogenous heterocycles utilizing a cyano-N-aryl-acetamide-reagent, notably chlorinated thiazolidine, thiophene and 2-iminochromene derivatives. Thus, the precursor 2-cyano-N-(2,4-dichlorophenyl) acetamide 1 underwent the reaction with phenyl isothiocyanate in DMF/KOH to afford the intermediate salt 3, which reacted in situ with several α-halogenated reagents 4a-c like ethylchloroacetate,α-bromoethylpropionate and α-bromo ethyl butaneoate and afforded the corresponding 4-thiazolidinnone derivatives (6a–c, yield%; 67–85), thiophene derivatives (11;yield 80%) and (15, yield 77%) obtained from the reaction of 3 with α- chloroacetyl acetone 9 and ethyl 2-chloro-3-oxobutanoate 12.Novel series of different 4-thiazolidinones(16a–e; yield%; 65–84) were obtained via condensation of 6a with different aldehydes. Finally, the reaction of compound 1 with different bifunctional reagents, such as salicylaldehyde derivatives and 2-hydroxynaphthaldehyde, in ethanol furnished the iminochromenes (17a,b; yield %77,80) and (18; yield 85%). In addition, molecular docking studies of the prepared molecules were carried out against papain-like protease (PLpro) to identify novel promising inhibitors of Coronavirus Disease COVID-19. The binding affinity of the best docked compounds 16c and 16a toward the target enzyme was − 9.6 and − 8.9 kcal/mole, respectively. In silico-docking-Studies indicate, that compounds 16c and 16a have the potential as antiviral against COVID-19. [ABSTRACT FROM AUTHOR]

We present a simple method to prepare diverse benzimidazolium and imidazolium ionic liquids (ILs) from common starting materials imidazole and benzimidazole. These green ILs promote the synthesis of N‐substituted piperazinyl propargylamines via a versatile CuI‐catalyzed coupling of aldehydes, secondary amines, and alkynes under ultrasound. Remarkably, the method works across a broad range of substrates, including diversely substituted aldehydes, heterocycles, cyclic amines, and phenylacetylenes. To understand this versatility, we investigated the influence of IL structure (N‐substitution, anion) on reactivity. Symmetrical long‐chain substituents on the benzimidazolium cation and bromide (Br−) anions led to the most efficient propargylamine formation. This approach offers a sustainable and efficient route to propargylamines with minimal waste and catalyst/IL recyclability over five cycles. [ABSTRACT FROM AUTHOR]

Numerous synthetic routes have been established for the synthesis of organotin (IV) derivatives of carboxylates, thiocarbamates, thiols, alcohols, amines, Schiff bases, etc. However, no synthetic path has been still developed for the synthesis of organotin (IV) aldehydes. We have synthesized four O,S‐coordinated organotin (IV) aldehydes (1–4) of the general formulas LSn(S)(Cl)R2 (where R2 = Me2, n‐Bu2, Ph2 for 1–3, respectively) and LSn(S)Ph3 (4) by reaction of 4‐(dimethylamino)benzaldehyde (L) with KOH, CS2, and R2SnCl2/Ph3SnCl in methanol. The synthesized products were characterized by microanalysis (CHN), FT‐IR analysis, UV–visible spectroscopy, NMR spectroscopy (1H and 13C), thermogravimetric analysis (TGA), computational studies, and single‐crystal XRD. Elemental analysis data were agreed well with the molecular composition of the products. FT‐IR spectroscopy has shown a significant lowering of C=O vibrational frequency after ligand–metal coordination. The electronic spectroscopy of complexes 1–4 demonstrated the π–π* (342–343 nm) and n–π* (279–296 nm) transitions, with the band gap values of 3.15–3.38 eV. 1H NMR spectra displayed distinct signals for the ligand skeleton and organotin (IV) moieties. 13C NMR spectroscopy exhibited an upfield shift of carbonyl oxygen after ligand–metal coordination. The thermogravimetric analysis revealed the thermal stabilities of complexes up to a temperature of 190 to 320°C. Single‐crystal XRD analysis of product 4 has shown a distorted trigonal bipyramidal geometry around Sn (IV), in which the three phenyl groups were positioned equatorially while the carbonyl oxygen (from the aldehyde) and the sulfur atom occupied the apical positions. Employing the 6‐31G(d,p) basis set and the CAM‐B3LYP functional, time‐dependent density functional theory (TD‐DFT) computations were performed for the calculation of absorbance maxima, oscillator strength (f), and matching molecular designations. MEP maps and HOMO–LUMO energy gaps were predicated on the CAM‐B3LYP/6‐31+g(d,p) level of theory and were used to resolve GRD, including chemical potential (μ), global hardness (η), global softness (S), electronegativity (χ), electrophilicity (ω), ionization potential (IP), and electron affinity (EA). The phenyltin (IV) derivatives (3 and 4) have shown a fantastic biofilm inhibition of Escherichia coli, which was even higher as compared with that of the reference drug ciprofloxacin. The bioactivity of 2 against Bacillus subtilis was equivalent to that of the ciprofloxacin. The products 2 and 3 have shown very little (less than 10%) toxic hemolytic effects demonstrating their possible safe use for the human beings. [ABSTRACT FROM AUTHOR]

BACKGROUND: Biogenic amines (BA) are hazardous components in Huangjiu (HJ). To ensure the quality of Dangshen Huangjiu (DSHJ), an orthogonal experiment L9 (33) was proposed to optimize the process by the main brewing factors (pre‐fermentation temperature, pre‐ and post‐fermentation time) that may affect BA and functional factors in DSHJ. DSHJ was produced with low BA content and high functional factors. Gas chromatography–ion mobility spectrometry combined with a multivariate statistical method (GC‐IMS‐MSM) was used to analyze the volatile components in the brewing process of DSHJ. RESULTS: The optimum brewing process parameters of DSHJ were as follows: pre‐fermentation temperature, 28 °C; pre‐fermentation time, 9 days; post‐fermentation time, 18 days. The average content of BA in DSHJ was 33.12 mg L−1, and the sensory score, total phenol content and DPPH free radical scavenging rate of DSHJ were significantly higher than those of HJ. A total of 14 esters, 7 acids, 7 alcohols, 1 ketone, 5 aldehydes and 1 pyrazine in DSHJ and HJ were identified by GC‐IMS. There were no significant differences (P > 0.05) in DSHJ and HJ in the soaking rice and saccharification stage. 11 components, such as ethyl acetate, and 12 components, such as acetic acid, were the different components of HJ and DSHJ in pre‐fermentation and post‐fermentation stages, respectively. In the post‐fermentation stage, the contents of 8 components in DSHJ such as ethyl acetate were higher than in HJ. CONCLUSION: The preparation process parameters of DSHJ optimized by orthogonal experiments can ensure that DSHJ has the advantages of low BA content, high total phenol content and good antioxidant activity. Sensory score and GC‐IMS‐MSM analysis found that DSHJ prepared using the optimal process had the characteristics of good taste and rich aroma. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

A one-pot, one-step protocol combining hydrogen transfer initiated dehydration (HTID) of 1,3-propanediol (1,3-PDO), catalysed by [Cp*IrCl2(NHC)] (Cp* = pentamethylcyclopentadienyl; NHC = carbene ligand) complexes (1-5H and 1-3F), and self-aldol condensation (SAC) of propanal (2), allowed selective production of C6 aldehyde 2-methyl-pent-2-enal (3), in ionic liquids with high substrate conversion. This shows, for the first time, the conversion of 1,3-propanediol to C6 aldehydes in one pot via a catalytic hydrogen borrowing methodology. The Ir(III) pre-catalysts and the ionic liquids were recyclable. C6 aldehyde 2-methyl-pent-2-enal could also be selectively produced in the presence of water and in neat 1,3-PDO. The efficient, selective delivery of a value-added chemical from 1,3-PDO, a major product of many whole-cell bacterial fermentation processes, shows that the combination of chemo-catalytic processing of the chemical platform via Cp*IrCl2(NHC)-catalysed HTID/SAC with bio-catalysis has the potential to allow direct valorisation of the bio-renewable feedstocks, such as waste glycerol and sugars, into valuable chemicals. [ABSTRACT FROM AUTHOR]

I report a simple and efficient one-pot route for the synthesis of 1-[aryl(selenoacetamido)methyl]-2-naphthol derivatives from the condensation of 2-naphthol, an aryl aldehydes and selenoacetamide in the presence of catalytic amounts of p-toluenesulfonic acid (p-TSA) under reflux conditions. This new protocol offers advantages such as mild reaction conditions, short reaction time, easy work-up, and use of an inexpensive and nontoxic catalyst and good yields. [ABSTRACT FROM AUTHOR]

This study reports the synthesis and computational investigation of two Schiff bases: (E)-N-(4-bromophenyl)-1-(2,6-dichlorophenyl)methanimine (S1) and (E)-4-(((4-bromophenyl)imino)methyl)phenol (S2), with a focus on their potential antibacterial activity. Schiff bases, known for their versatility and application in medicinal chemistry, are synthesized through the condensation reactions of the appropriate aniline with aldehydes. The molecular structures of S1 and S2 were elucidated using basic spectroscopic methods such as Fourier-transform-infrared, ultraviolet-visible as well as ¹H and 13C-NMR, while the purity of the compounds was ascertained using elemental analysis. The stability, chemical reactivities, and electronic properties of S1 and S2 were evaluated using Density Functional Theory (DFT). The energy band gap (ΔE) of S1 and S2 is 2.81 eV and 3.02 eV, respectively, and this infers that S1 is more reactive as well as less stable than S2. The molecular electrostatic potential (MEP) mapping evaluation showed that both S1 and S2 have more of the yellow, green, and red regions than the blue region, signifying that these structures are prone to electrophilic attack. The compounds were screened against two Gram-negative (Klebsiella pneumoniae and Pseudomonas aeruginosa) and one Gram-positive bacteria (Staphylococcus aureus) to evaluate their antibacterial potential. S1 as well as S2 showed antibacterial potential against Staphylococcus aureus and exhibited less or no activity against Klebsiella pneumoniae and Pseudomonas aeruginosa. In silico studies of S1 and S2 against Staphylococcus aureus were carried out, and the outcomes corroborated the experimental findings. Pharmacological evaluation of S1 and S2 showed that both compounds exhibited less violation of Lipinski’s rule of five (Ro5), which makes them less toxic and orally available. [ABSTRACT FROM AUTHOR]

The composition and nature of changes in the low-molecular-weight metabolome (LMWM) of Potamogeton perfoliatus L. growing in six biotopes of Lake Ladoga with different types of anthropogenic load have been analyzed. According to the results, it is found that the total number of low-molecular-weight organic compounds (LMWOCs) in the P. perfoliatus LMWM composition is directly dependent on anthropogenic load, which is well marked by the development of cyanobacteria. The greater the intensity of pollution or eutrophication of waters, or the higher the number of cyanobacteria, the lower the total number of LMWOCs and their concentration. A strongly pronounced dependence of the total concentrations of groups of LMWM compounds on the anthropogenic disturbance of the biotope and the concentration of cyanobacteria is revealed. A decrease in the number, relative amount, total concentration of carboxylic acids, and number and content of unsaturated fatty acids and an increase in the composition and content of phenols and the total content of aldehydes and ketones depends on an increase in anthropogenic pressure. The specific composition of the LMWM of claspingleaf pondweed depends on its response to biotic and abiotic factors of the aquatic (including anthropogenic) environment. The features of the change in the composition of the P. perfoliatus LMWM make it possible to use it as an integral indicator of the anthropogenic impact on the littoral biotopes of water bodies and the deterioration of their ecological state. [ABSTRACT FROM AUTHOR]

There is a demand from the scientific, beekeeping and consumer sectors to characterize honey based on its botanical origin, as it provides unique and distinctive properties. Nevertheless, existing studies on the physicochemical properties and the sensorial profile of honey in relation to botanical origin remain insufficient. This study aimed to understand the relationships between sensory profile and various chemical compounds (minerals, sugars, water content and volatiles) of three monofloral honeys (Atractylis serratuloides, Retama sphaerocarpa and Eruca sativa) produced in Algeria using principal component analysis. Crystallization was detected as a distinctive attribute of Eruca and Atractylis honey. A candy aroma and odor with floral nuances, light color, crystallized state and the volatile compounds Alpha-Bisabolol and Beta-eudesmol characterized the Atractylis honey. Eruca honeys were distinguished by an animal and degraded odor, bitter taste, light color and the presence of Dimethyl trisulfide and Dimethyl tetrasulfide. Finally, a vegetal aroma, some saltiness and sourness, dark amber color, lower sugar content, higher K content and Lilac aldehyde and Lilac aldehyde D characterized Retama honeys. [ABSTRACT FROM AUTHOR]

Electrocatalytic hydrogenation of unsaturated aldehydes to unsaturated alcohols is a promising alternative to conventional thermal processes. Both the catalyst and electrolyte deeply impact the performance. Designing the electrode‐electrolyte interface remains challenging due to its compositional and structural complexity. Here, we employ the electrocatalytic hydrogenation of 5‐hydroxymethylfurfural (HMF) as a reaction model. The typical cationic surfactant, cetyltrimethylammonium bromide (CTAB), and its analogs are employed as electrolyte additives to tune the interfacial microenvironment, delivering high‐efficiency hydrogenation of HMF and inhibition of the hydrogen evolution reaction (HER). The surfactants experience a conformational transformation from stochastic distribution to directional assembly under applied potential. This oriented arrangement hampers the transfer of water molecules to the interface and promotes the enrichment of reactants. In addition, near 100 % 2,5‐bis(hydroxymethyl)furan (BHMF) selectivity is achieved, and the faradaic efficiency (FE) of the BHMF is improved from 61 % to 74 % at −100 mA cm−2. Notably, the microenvironmental modulation strategy applies to a range of electrocatalytic hydrogenation reactions involving aldehyde substrates. This work paves the way for engineering advanced electrode‐electrolyte interfaces and boosting unsaturated alcohol electrosynthesis efficiency. [ABSTRACT FROM AUTHOR]

Obtaining information about cellular interactions is fundamental to the elucidation of physiological and pathological processes. Proximity labeling technologies have been widely used to report cellular interactions in situ; however, the reliance on addition of tag molecules typically restricts their application to regions where tags can readily diffuse, while the application in, for example, solid tissues, is susceptible. Here, we propose an "in‐situ‐tag‐generation mechanism" and develop the GalTag technology based on galactose oxidase (GAO) for recording cellular interactions within three‐dimensional biological solid regions. GAO mounted on bait cells can in situ generate bio‐orthogonal aldehyde tags as interaction reporters on prey cells. Using GalTag, we monitored the dynamics of cellular interactions and assessed the targeting ability of engineered cells. In particular, we recorded, for the first time, the footprints of Bacillus Calmette‐Guérin (BCG) invasion into the bladder tissue of living mice, providing a valuable perspective to elucidate the anti‐tumor mechanism of BCG. [ABSTRACT FROM AUTHOR]

A series of some new 1,3,4‐oxadiazole derivatives was synthesized. Hydrazide derivative 4 was reacted with some sugar aldehydes to give the corresponding sugar hydrazones 5 a–c. Acetylation of 5 a–c with acetic anhydride in pyridine, managed the per‐O‐acetyl derivatives 6 a–c while refluxing in acetic anhydride gave the corresponding 1,3,4‐oxadiazolines 7 a–c. On the other hand, 1,3,4‐oxadiazoles 8 a,b, 9, 10, 12, 14, and 15 were synthesized via the reaction of 4 with different reagents including p‐chlorobenzoic acid, nicotinic acid, methyl iodide, morpholine, phenyl isothiocyanate, potassium iodide, chloroacetyl chloride, and phosphorus oxychloride, respectively. The new compounds were assessed for their anticancer and antioxidant activities. Compounds 8 a,b, 10, and 12–15 displayed the most antioxidant activity. In addition, compounds 8 a, 8 b, and 13 showed strong cytotoxic activity. [ABSTRACT FROM AUTHOR]

A first metal‐free protocol for the synthesis of allylic sulfones featuring aldehyde functionality at the δ‐position has been reported. The formation of structurally complex δ,δ‐dimethoxy allylic sulfones is enabled by the direct nucleophilic attack of methoxide onto the sulfone‐containing 1,3‐enynes. The present approach allows facile installation of acetal groups within the allylic sulfone scaffold, providing versatile platforms for further functionalization and drug development. [ABSTRACT FROM AUTHOR]

A facile method for the chemodivergent synthesis of α-carbolines 1via palladium catalyzed [3+3] annulations of tosyliminoindolines 6 with α, β-unsaturated aldehydes 7 is described. Mechanistically, this cascade reaction proceeds through either a carba-Michael (in DMF) or aza-Michael (in NMA) pathway followed by intramolecular cyclization of the intermediate. A preliminary photo-physical study on selected products is also reported. [ABSTRACT FROM AUTHOR]

We herein report that the highly hydrophobic ether 4‐MeTHP constitutes a promising resource for the development of sustainable synthetic methodologies grounded on the use of organometallic reagents. The beneficial effects of 4‐MeTHP as reaction medium are illustrated in the organolithium‐promoted anionic ortho‐Fries rearrangement of 1,1'‐bi‐2‐naphthol (BINOL)‐based carbamates under bench‐type conditions. The use of 4‐MeTHP induces a remarkable and unexpected stability of the organolithiums species, enabling the efficient preparation of chiral (bis)carboxamide catalysts. Furthermore, superior performances of 4‐MeTHP than other environmentally responsible solvents are observed using the synthesized BINOL catalysts in the asymmetric addition of organozinc reagents to aldehydes. Spectroscopic studies in solution suggest that 4‐MeTHP plays a key role in these reactions by inducing the preferential formation of a reactive monomeric dinuclear complex. This methodology allows for the asymmetric assembly of enantioenriched secondary alcohols in good yields and high stereoselectivity, working at 0 °C and under air. [ABSTRACT FROM AUTHOR]

The formyl C−H thiolation of aldehydes using thiosulfonates and the decatungstate anion as a photocatalyst is reported. Using this photocatalytic protocol together with a CO atmosphere, both aromatic and aliphatic thioesters can be synthesized in good yields. The transformation consists of a cascade of double SH2 reactions, HAT and an ArS group transfer. CO atmosphere effectively limits the extent of decarbonylation of acyl radicals that are generated in the reaction. [ABSTRACT FROM AUTHOR]

Bee pollen's nutritional and beneficial health properties depend on the botanical origin and storage conditions. Palynological analysis determines the botanical composition of the multiflora and colour fractions. This study aimed to characterize the phytochemical profile and antioxidant activity of Tuscan bee pollen stored at freezing temperature for 2 years to verify the preservation of nutraceutical properties of the multiflora and colour fractions. Polyphenols, flavonoids content, antioxidant activity and volatile compounds profiles were measured. Non-terpene derivatives (acids and aldehydes) represented the main class of volatile compounds in most analysed samples. Among the colour fractions, coral showed significant differences in the antioxidant compounds. In the multiflora were also determined the soluble sugar content (128.33 mg/g of fresh weight) and mineral content, with the prevalence of K, organic N and Ca. The results suggest that the freezing storage of bee pollen for a long period can be still used as food. [ABSTRACT FROM AUTHOR]

The macrocyclic tumonolide (1) with enamide functionality and the linear tumonolide aldehyde (2) are new interconverting natural products from a marine cyanobacterium with a peptide‐polyketide skeleton, representing a hybrid of apratoxins and palmyrolides or laingolides. The planar structures were established by NMR and mass spectrometry. The relative configuration of the stereogenically‐rich apratoxin‐like polyketide portion was determined using J‐based configuration analysis. The absolute configuration of tumonolide (1) was determined by chiral analysis of the amino acid units and computational methods, followed by NMR chemical shift and ECD spectrum prediction, indicating all‐R configuration for the polyketide portion, as in palmyrolide A and contrary to the all‐S configuration in apratoxins. Functional screening against a panel of 168 GPCR targets revealed tumonolide (1) as a selective antagonist of TACR2 with an IC50 of 7.0 μM, closely correlating with binding affinity. Molecular docking studies established the binding mode and rationalized the selectivity for TACR2 over TACR1 and TACR3. RNA sequencing upon treatment of HCT116 colorectal cancer cells demonstrated activation of the pulmonary fibrosis idiopathic signaling pathway and the insulin secretion signaling pathway at 20 μM, indicating its potential to modulate these pathways. [ABSTRACT FROM AUTHOR]