Good Yields Research Articles

Synthesis of the pyruvic acid acetal containing tetrasaccharide repeating unit corresponding to the K82 capsular polysaccharide of Acinetobacter baumannii LUH5534 strain

An efficient synthetic strategy has been developed to achieve a pyruvic acid acetal containing tetrasaccharide repeating unit corresponding to the K82 capsular polysaccharide of Acinetobacter baumannii LUH5534 strain in very good yield. The synthetic scheme involves the use of suitably functionalized monosaccharide thioglycosides as glycosyl donors and a combination of N-iodosuccinimide (NIS) and trimethylsilyl trifluoromethanesulfonate (TMSOTf) as thiophilic glycosylation activator to furnish satisfactory yield of the products with appropriate stereochemistry at the glycosidic linkages. Incorporation of the (R)-pyruvic acid acetal in the D-galactose moiety was achieved in very good yield by the treatment of the diol derivative with methyl 2,2-bis(p-methylphenylthio)propionate in the presence of a combination of NIS and triflic acid.

Performance and Evaluation of Hanski 227 Oriental Tobacco in Dak Lak Region, Vietnam from 2022 - 2024

With the results of selecting Oriental tobacco varieties suitable for natural conditions in Vietnam, with potential for raw material quality and raw material production capacity in Vietnam, from 6 oriental tobacco varieties originating from Bulgaria, the Tobacco Institute has been testing in Ninh Thuan province from 2019 to 2021, and Dak Lak from 2021 to 2022. The results of the trial planting show that oriental tobacco varieties are good growth, and are quite suitable for the soil and climate conditions in Ninh Thuan and Dak Lak provinces, and have selected 2 the best oriental tobacco varieties as Basma 16 and Hanski 227. In which, Hanski 227 variety is evaluated to have outstanding prospects due to its good growth ability, high yield, characteristic aroma and good smoking properties. The Hanski 227 variety has less harvested leaves, larger leaf size and mass than Basma 16 variety, so the labor costs for cultivation, harvesting and preliminary processing are lower. To evaluate the ability to expand the oriental area in Vietnam, we continue to trial planting the Hanski 227 oriental variety in Dak Lak in 2023 - 2024, with a fertilizer level and a planting density corresponding to 50N + 30P2O5 + 80K2O (N: NH4NO3, P: (Ca(H2PO4)2 and K: K2SO4) and 110,000 plants/ha. The experimental trial results show the Hanski 227 variety has good growth, high yield, and good quality, with yield fluctuating 1.52 - 1.66 tons/ha, nicotine content: 0.81 - 1.38%, and reducing sugar content: 8.9 - 12.1%, and the oriental material has a characteristic aroma and good smoking properties. Based on the trial results shows that the quality of Hanski 227 grown in Dak Lak are the same the oriental tobacco importing from Bulgaria, Türkiye and Greece. Therefore, the Dak Lak province is the most suitbale region for producing good quality oriental tobacco in Vietnam compared to Ninh Thuan region. Because materials in Ninh Thuan has the high clorua content reducing material quality. In 2025, we continue to grow the Hanski 227 oriental tobacco variety in Dak Lak region on a large area and complete the preliminary processing process, with the goal of producing Oriental tobacco raw materials domestically, with appropriate production costs.

Green synthesis, characterization, antioxidant, anti-fungal, antibacterial activities of a new 1-isopropyl-3,5-di-2-tolyl-1,3,5-triazacyclohexane

This work presents the green synthesis of a novel of 1- isopropyl- 3, 5- di-2-tolyl- 1, 3, 5-triazacyclohexane in good yield. It is made without a solvent, energy, and a catalyst as a green technique via a one-pot multi component condensation reaction between one equivalent of isopropylamine, two equivalents of o-toluidine, and three equivalents of formaline. The compound's structure has been determined using several spectroscopic methods, including thin-layer chromatography (TLC), ultraviolet-visible spectroscopy (UV-Vis), infrared spectroscopy (IR), and nuclear magnetic resonance spectroscopy (NMR) for both 1H and 13C nuclei. Additionally, the compound 'smelting point was determined. Subsequently, the molecule was evaluated for its antioxidant and biological activities. The antioxidant activity exhibited good performance in both the ABTS and Phenanthrolinetests. The antimicrobial activity of this novel compound was tested against four bacterialstrains, including two Gram-positive bacteria (Staphylococcus aurous ATCC 25923 and Bacillus cereus ATCC 10876) and two Gram-negative bacteria (Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853), as well as two fungal strains (Fusarium oxysporum and Alternariaalternata)using the agar diffusion method and the direct contact method, respectively. The obtained results exhibited a high level of antibacterial and antifungal activity.

New Arene and/or Heteroarene‐Linked 1,3,4‐Oxadiazoles: Synthesis of Potential Methicillin‐Resistant Staphylococcus aureus and Vancomycin‐Resistant Enterococcus Inhibitors

AbstractBacterial infections, particularly those associated with methicillin‐resistant Staphylococcus aureus (MRSA) and vancomycin‐resistant Enterococcus (VRE), threaten public health and economies, with rising antibiotic resistance resulting in more deaths yearly. In this study, we investigated the bacterial inhibitory activity of some new 1,3,4‐oxadiazoles prepared, in good yields, using a two‐step tandem protocol. Therefore, the appropriate N‐benzoylhydrazones were prepared first, then, without isolation, underwent oxidative‐cyclization in the presence of chloramine trihydrate. More 4‐acyloxyphenyl‐linked 1,3,4‐oxadiazoles were prepared by the pyridine‐mediated acylation of 2‐(4‐hydroxyphenyl)‐1,3,4‐oxadiazoles with the appropriate acyl chlorides. Some new products demonstrated good activity, particularly against S. aureus and Enterococcus faecalis strains. The 4‐(5‐(furan‐2‐yl)‐1,3,4‐oxadiazol‐2‐yl)phenyl acetate showed comparable antibacterial activity to ciprofloxacin, with MIC/MBC values up to 3.6/7.2 µM against the previous strains. Moreover, it demonstrated good inhibitory activity against different MRSA and VRE strains when compared to linezolid. It had MIC/MBC values of 7.2/14.4 and 14.4/57.8 µM against MRSA and VRE strains, respectively.

Ultrasound-assisted Synthesis of Novel 4-[3-acetyl-2-(N-alkyl(aryl)acetamido)-1,3, 4-thiadiazol-5-yl]-3-(2-oxo-2H-chromen-3-yl)-1-(4-phenylthiazol-2-yl)-1H-pyrazoles: Anticancer Activities, Apoptotic, Cell Cycle, Molecular Docking, and ADMET Studies

Abstract: A novel series of 4-[3-acetyl-2-(N-alkyl(aryl)acetamido)-1,3,4-thiadiazol-5-yl]-3-(2-oxo-2Hchromen- 3-yl)-1-(4-phenylthiazol-2-yl)-1H-pyrazoles (2a-i) and 3 was synthesized in good yields. The methodology was depended on a one-pot four-components reaction of hydrazine hydrate, alkyl(aryl) isothiocyanate, 3-(2-oxo-2H-chromen-3-yl)-1-(4-phenylthiazol-2-yl)-1H-pyrazole-4-carboxaldehyde (1), and acetic anhydride in acetic acid under ultrasound irradiation. The spectral tools confirmed the structures of all synthesized compounds. Using the standard SRB method, the designed compounds were screened for their in vitro cytotoxicity properties against PC3, HepG2, and HCT116 human cancer cell lines. Products 2a and 2c worked best against all cancer cells tested, as well as doxorubicin. Apoptosis and cell cycle analyses were performed for the bioactive products 2a and 2c. Both products strongly impacted all tumor cells in the late apoptotic pathway and significantly inhibited all cancer cell types under investigation in both the S and G2 phases. After that, a molecular docking study was carried out on products 2a and 2c to investigate how they interact with the CDK-8 receptor. The ADMET prediction suggested that these bioactive products may be effective anticancer treatments.

Synthesis of Chiral Endocyclic Allenes and Alkynes via Pd-Catalyzed Asymmetric Higher-Order Dipolar Cycloaddition.

A Pd-catalyzed asymmetric higher-order dipolar cycloaddition between allenyl carbonates and azadienes is achieved by exploiting novel alkylidene-π-allyl-Pd dipoles. This research provides a modular platform for the synthesis of challenging chiral endocyclic allenes bearing a medium-sized heterocyclic motif and a centrally chiral stereocenter in good yields with high enantio- and diastereoselectivities (29 examples, up to 97% yield, 97:3 er and >19:1 dr). Experimental and computational studies elucidate the possible reaction mechanism and the observed stereochemical results. Based on the mechanistic understanding, a new π-propargyl-Pd dipole was designed to further extend the success of the higher order dipolar cycloaddition strategy to the synthesis of 10-membered endocyclic alkynes from propargyl carbonates and azadienes (13 examples, up to 98% yield and 94.5:5.5 er).

Microwave and ultrasound-assisted green protocols for 5-methylthiazole induced Betti bases: molecular docking, in-silico pharmacokinetics, and anticancer activity studies

ABSTRACT Herein, we describe an efficient one-pot three-component microwave and ultrasound-endorsed approaches for synthesizing distinct 5-methylthiazole induced Betti bases (5-methyl-thiazol-2-ylamino-aryl-benzylnapthols) employing silica sulfuric acid (SSA, silica-OSO3H) as an active heterogeneous acid catalyst. The title compounds produced in good yields (86–95%) from naphthalen-2-ol, 5-methylthiazol-2-amine, and assorted aryl aldehydes; and structurally characterized by spectral and elemental analyses. A comprehensive comparative study of conventional, ultrasonic, and microwave-irradiated synthetic routes has been achieved by optimizing various reaction parameters. These new protocols provide several advantages, including the use of an inexpensive, non-toxic, and reusable catalyst. Additionally, they benefit from mild reaction conditions, short reaction times, and simple workup and purification procedures, thereby increasing their practicality. Furthermore, the synthesized compounds were evaluated for their anticancer potency against A-549 (lung cancer) and A-498 (kidney cancer) cell lines, with scaffold IVa demonstrating excellent (GI50 < 10 µg/mL) inhibitory activity against A-549. Additionally, molecular docking was performed to investigate potential binding interactions between ligands and proteins. Scaffold IVa exhibited the best docking with cancerous target proteins 1M17 (−8.9 kcal/mol) and 1M14 (−7.2 kcal/mol), thereby supporting our bio-activity studies.

Controlling the Size of Molecular Copper Clusters Supported by a Multinucleating Macrocycle.

The use of a nonrigid, pyridyldialdimine-derived macrocyclic ligand (3PDAI2) enabled the synthesis of well-defined mono-, di-, tri-, and tetra-nuclear Cu(I) complexes in good yields through rational synthetic means. Starting from mono- and diargentous 3PDAI2 complexes, transmetalation to Cu(I) proceeded smoothly with formation of AgX (X = Cl, I) salts to generate mono-, di-, and trinuclear copper complexes. Monodentate supporting ligands (MeCN, xylNC, PMe3, PPh3) were found to either transmetallate with or bind various di- and trinuclear clusters. The solution-phase dynamic behaviors of these species were studied through NMR spectroscopic investigations, and an in-depth study of the trinuclear systems revealed a rate dependence on the identity of the supporting ligand, indicating that ligand dissociation reactions were involved in the dynamic exchange processes. Synthetic investigations further found methods for the purposeful interconversion between the di- and trinuclear systems as well as the synthesis of a pseudotetrahedral tetracopper complex with two μ-Ph supporting ligands.

Nickel-catalyzed thiocarbonylation for the synthesis of thioesters-functionalized 2H-pyrones with sulfonyl chlorides as the sulfur sources

An efficient and straightforward protocol for the synthesis of thioesters-functionalized 2H-pyrones has been explored through a nickel-catalyzed thiocarbonylation reaction with sulfonyl chlorides as the sulfur sources. By using Mo(CO)6 as both CO source and reductant, a diverse set of thioesters-containing 2H-pyrones have been obtained in moderate to good yields. This reaction provides a good supplement for the carbonylative synthesis of thioesters-functionalized 2H-pyrones via a Ni/Mo(CO)6 catalytic system.

Exploring Thinopyrum spp. Group 7 Chromosome Introgressions to Improve Durum Wheat Performance under Intense Daytime and Night-Time Heat Stress at Anthesis

Durum wheat (DW) is one of the major crops grown in the Mediterranean area, a climate-vulnerable region where the increase in day/night (d/n) temperature is severely threatening DW yield stability. In order to improve DW heat tolerance, the introgression of chromosomal segments derived from the wild gene pool is a promising strategy. Here, four DW-Thinopyrum spp. near-isogenic recombinant lines (NIRLs) were assessed for their physiological response and productive performance after intense heat stress (IH, 37/27 °C d/n) had been applied for 3 days at anthesis. The NIRLs included two primary types (R5, R112), carriers (+) of a differently sized Th. ponticum 7el1L segment on the DW 7AL arm, and two corresponding secondary types (R69-9/R5, R69-9/R112), possessing a Th. elongatum 7EL segment distally inserted into the 7el1L ones. Their response to the IH stress was compared to that of corresponding non-carrier sib lines (−) and the heat-tolerant cv. Margherita. Overall, the R112+, R69-9/R5+ and R69-9/R112+ NIRLs exhibited a tolerant behaviour towards the applied stress, standing out for the maintenance of leaf relative water content but also for the accumulation of proline and soluble sugars in the flag leaf and the preservation of photosynthetic efficiency. As a result, all the above three NIRLs (R112+ &gt; R69-9/R5+ &gt; R69-9/R112+) displayed good yield stability under the IH, also in comparison with cv. Margherita. R112+ particularly relied on the strength of spike fertility/grain number traits, while R69-9/R5+ benefited from efficient compensation by the grain weight increase. This work largely confirmed and further substantiated the value of exploiting the wild germplasm of Thinopyrum species as a useful source for the improvement of DW tolerance to even extreme abiotic stress conditions, such as the severe heat treatment throughout day- and night-time applied here.

Synthesis, Structural, Electrochemical, and DFT Studies of Highly Substituted Nonplanar Ni(II) Porphyrins and Their Intensity-Dependent Third-Order Nonlinear Optical Properties.

We designed and successfully synthesized highly substituted electron-deficient nonplanar Ni(II) porphyrins and their derivatives (1-7) in moderate to good yields. These derivatives were comprehensively characterized by various spectroscopic techniques and single-crystal X-ray diffraction (SCXRD) analysis. SCXRD analysis confirmed the structures of compounds 2, 4, and 7, adopting saddle-shape geometry. These nonplanar porphyrins demonstrated significant bathochromic shifts in their absorption spectra compared to parent NiTPP, attributed to the influence of bulky β-substituents and/or peripheral fusion. π-Extended porphyrins 6 and 7 displayed panchromatic absorption spectra extending into the NIR region. Porphyrins 6 and 7 demonstrated a profound anodic shift (∼400 mV) in their first reduction peak potentials compared to precursor NiTPP(NO2)Br6. The experimental absorption spectral pattern matches the simulated absorption spectra obtained from TD-DFT studies. The femtosecond laser intensity-dependent third-order nonlinear optical studies revealed that NiDFP(VCN)2Br6 (6) and NiDFP(VCN)2(PE)6 (7) displayed giant optical nonlinearities compared to the other porphyrins. Among all, NiDFP(VCN)2Br6 (6) possessed the highest two-photon absorption coefficient (β) and cross-section (σTPA) values in the range of 22-33 × 10-10 m/W and 3.77-6.95 × 106 GM, respectively. These findings suggest that the investigated nonplanar π-extended porphyrins are promising candidates for future optoelectronic applications.

Sustainable N-Formylation of Anilines: Harnessing Aleuritic Acid as a Renewable Formyl Source

Abstract N-Formylation of anilines using a renewable aleuritic acid as an eco-friendly and sustainable formylating source has been developed. para-Substituted anilines generally provided good yields, while moderate yields were observed with meta- and ortho-substituted derivatives. In situ generated formic acid through oxidative cleavage of aleuritic acid serve as a formyl source, which has been confirmed through control experiments.

Facile Synthesis of Diverse 1,3,5‐Trisubstituted 1,2,4‐Triazole using Hydrazones with Aldehydes, Alkenes, Amines

An efficient, and easy method for the synthesis of 1,3,5‐ substituted 1,2,4‐triazole derivatives by [3+2] annulation reactions of hydrazones with aldehydes, alkenes, or amines has been established. This strategy is characterized by the use of inexpensive and readily available oxidants and starting materials, a broader substrate scope, and moderate to good yields.

Application of Biotechnology and Chiral Technology Methods in the Production of Ectoine Enantiomers

Natural ectoine, (+)-(4S)-2-methyl-1,4,5,6-tetrahydropyrimidine-4-carboxylic acid, is an extremely important small biomolecule belonging to the class of osmolytic/osmoprotective compounds. It stabilizes biomacromolecules such as DNA and proteins and protects them from denaturation by heat, dehydration, and UV radiation. The rapidly growing interest in this compound resulted in currently exclusive biotechnological production, while a chemical process along with enantioseparation as an alternative has not yet been established. An improved chemical synthesis of racemic ectoine starting from γ-butyrolactone in very good yield is described. Regioselective monoacetylation is achieved by the complexation of a copper(II)-ion with two molecules of 2,4-diamonobutyric acid in the key synthetic step. The racemic ectoine was synthesized with the aim of being successfully enantioseparated for the first time by high-performance liquid chromatography (HPLC) using a teicoplanin-based Chiral-T column in different solvent systems. The presence of (+)-ectoine was determined and quantified using an HPLC protocol on the Synergy Polar-RP column in fermentation broths inoculated with different strains of Streptomyces sp. bacteria isolated from the Adriatic Sea and grown on different NaCl concentrations.

4-Halomethyl-Substituted Imidazolium Salts: a Versatile Platform for the Synthesis of Functionalized NHC Precursors.

N,N'-Diarylimidazolium salts containing haloalkyl functional groups that are reactive with various nucleophiles are considered to be promising reagents for the preparation of functionalized N-heterocyclic carbene (NHC) ligands, which are in demand in catalysis, materials science, and biomedical research. Recently, 4-chloromethyl-functionalized N,N'-diarylimidazolium salts became readily available via the condensation of N,N'-diaryl-2-methyl-1,4-diaza-1,3-butadienes with ethyl orthoformate and Me3SiCl, but these compounds were found to have insufficient reactivity in reactions with many nucleophiles. These chloromethyl salts were studied as precursors in the synthesis of bromo- and iodomethyl-functionalized imidazolium salts by halide anion exchange. The 4-ICH2-functionalized products were found to be unstable, whereas a series of novel 4-bromomethyl functionalized N,N'-diarylimidazolium salts were obtained in good yields. These bromomethyl-functionalized imidazolium salts were found to be significantly more reactive towards various N, O and S nucleophiles than the chloromethyl counterparts and enabled the preparation of previously inaccessible heteroatom-functionalized imidazolium salts, some of which were successfully used as NHC proligands in the preparation of Pd/NHC and Au/NHC complexes.

Syntheses of Phosphonylated Pyrido-Dihydrofurans by Regioselective 5-Exo-dig Addition to Carbon-Carbon Triple Bond Catalyzed by AgNO3.

The tandem nucleophilic addition-cyclization reaction of o-alkynylpyridinecarbaldehyde 1 with dialkyl phosphites 2 took place very smoothly in the presence of AgNO3 under base conditions in DCE at 50 °C. In all cases, the reaction proceeded in a regioselective manner leading to the 5-exo-dig phosphonylated pyrido-dihydrofurans 3 in moderate to good yields.

Crop yield estimation uncertainties at the regional scale for Saxony, Germany

AbstractIn times of climate change and global population growth, agricultural yield forecasts play an increasingly important role. For example, predicting yields as early as possible in the event of a drought is crucial for decision‐makers in politics, government, and business. The aim of this study was to provide precise yield predictions at agricultural regions as early as possible with a minimum amount of weather data. Random forest models were used for this purpose. Although more than 290,000 datasets were available for analysis, all models tended to be heavily overfitting, which can be explained by the strong fragmentation of the input data by crop, region, and prediction time. The models reacted very differently to unknown datasets. It was found that the regionally trained models achieved lower (≥10%) relative root mean square errors (RRMSEs) than the supra‐regionally trained models. Rapeseed and barley achieved good predictions. Wheat had good potential, too. Corn, potatoes, and sugar beet achieved often too high RRMSEs. The results showed that targeted model selection for each region and an extension of the training time series could enable very good regional yield forecasts for rapeseed and cereals in the future.

Cobalt-catalyzed hydrothiolation of alkynes for the diverse synthesis of branched alkenyl sulfides

Alkenyl sulfides have gained increasing prominence in medicinal chemistry and materials. Hydrothiolation of alkynes for the diverse synthesis of alkenyl sulfides is an appealing method. Herein, we report a cobalt-catalyzed Markovnikov hydromethylthiolation of alkynes to afford branched alkenyl methylsulfanes with good yields and high regioselectivity. This method also enables the diverse synthesis of branched alkenyl sulfides. The reaction shows good functional group tolerance and could be scaled up. The mechanistic studies including control experiments, deuterium-labeling experiments, and Hammett plot indicated alkynes insertion followed by electrophilic thiolation pathway.

A Facile Preparation of Tetrasubstituted Arylalkenes Catalyzed by p‐Toluenesulfonic Acid Monohydrate (p‐TsOH⋅H2O): Application in the Synthesis of the Intermediate of Tamoxifen

AbstractAn efficient synthesis of tetrasubstituted arylalkenes was readily achieved by the reaction of α‐(tert‐butyl)benzylic alcohols using p‐toluenensulfonic acid monohydrate as a Brønsted acid. A broad range of substrates was applicable for the reaction in good yield with high regioselectivity. The key intermediate in the synthesis of tamoxifen was produced using the present method as an example, and a plausible reaction mechanism was proposed by examining the reaction intermediates.

Synthesis of 1,1,3-Polyfunctionalized Cyclobutane Derivatives from the Reaction of Sulfur Ylides with Bicyclo[1.1.0]butanes.

1,1,3-Polyfunctionalized cyclobutane derivatives have been synthesized from sulfur ylides and bicyclo[1.1.0]butanes (BCBs). This protocol operates under mild reaction conditions without the need for catalysts, generally producing moderate to good yields of syn-addition derivatives with structural diversity. An unexpected intramolecular rearrangement mechanism has also been proposed.