Identifying the botanical origin of alcohol using H SNIF NMR: A case study of "polish vodka" PGI.

In this study, we utilized H SNIF NMR and chemometric techniques to differentiate the botanical origin of raw materials used in vodka production in Poland, specifically focusing on plants with C metabolism such as grain, potato, and sugar beet. Additionally, for the first time, mixtures of alcohols from different C plants were analysed to detect adulteration. Our goal was to determine if it is possible to detect the addition of a different raw material in vodka made from a mixture of alcohols derived from C plants.

Hydrazone Activation in the Aminocatalytic Cascade Reaction for the Synthesis of Tetrahydroindolizines.

In this Letter, we demonstrate the usefulness of hydrazone activation for the synthesis of biologically relevant tetrahydroindolizines. A pyrrol-derived hydrazone bearing a Michael acceptor moiety in the -alkyl side chain has been designed with the aim of participating in the aminocatalytic cascade reaction leading to the annulation of the new six-membered heterocyclic scaffold. The application of ()-(-)-α,α-diphenyl-2-pyrrolidinemethanol trimethylsilyl ether as the aminocatalyst allows for the iminium ion-enamine-mediated cascade to proceed in a fully stereoselective manner.

Dearomative, aminocatalytic formal normal-electron-demand aza-Diels-Alder cycloaddition in the synthesis of tetrahydrofuropyridines.

In the manuscript the application of dearomative formal normal-electron-demand aza-Diels-Alder cycloaddition in the synthesis of tetrahydrofuropyridines is described. The developed approach utilizes aminocatalytic activation of 2-alkyl-3-furfurals that proceeds formation of the dearomatized dienamine intermediate. Initially obtained cycloadducts have been subjected to subsequent transformations providing access to tetrahydrofuropyridines or functionalized cinnamates.

Pentaenolate activation in the organocatalytic allylic alkylation of indene-2-carbaldehydes.

In this manuscript, the application of pentaenolate intermediates in the allylic alkylation of indene-2-carbaldehydes with Morita-Baylis-Hillman (MBH) carbonates is described. The reaction has been carried out in a highly enantio- and diastereoselective manner due to the use of a chiral tertiary amine as a nucleophilic catalyst. The developed reactivity constitutes the first application of organocatalytic pentaenolate activation in asymmetric synthesis, expanding the arsenal of catalytic methods.

Asymmetric Organocatalysis in the Remote (3 + 2)-Cycloaddition to 4-(Alk-1-en-1-yl)-3-cyanocoumarins.

The application of organocatalytic bifunctional activation in the remote (3 + 2)-cycloaddition between 4-(alk-1-en-1-yl)-3-cyanocoumarins and imines derived from salicylaldehyde is demonstrated. Products, bearing two biologically relevant units, have been obtained with good chemical and stereochemical efficiency. The stereochemical outcome of the process results from the application of a quinine-derived catalyst.

Synthesis of cyclopent-1-enecarbonitriles a tandem Giese/HWE reaction initiated by visible light.

In the manuscript, a novel method for the preparation of cyclopent-1-enecarbonitriles tandem Giese/HWE reaction initiated by visible light in the presence of -Ir(ppy) as a photocatyst has been described. The cascade reactivity combining radical and polar processes has proven applicable for a wide range of -(acyloxy)phthalimides (which serve as precursors of the corresponding radicals) as well as diethyl ()-(1-cyano-2-arylvinyl)phosphonates. The key parameters responsible for the success of the described strategy are: visible light, 1 mol% of photoredox catalyst, base, anhydrous solvent and inert atmosphere.

Organocatalytic Asymmetric Approach to γ,δ-Functionalization of 3-Cyano-4-styrylcoumarins via Bifunctional Catalysis.

A novel organocatalytic reaction cascade between 3-cyano-4-styrylcoumarins and 2-mercaptoacetophenones is described. It is based on stereocontrolled functionalization of cyanocoumarins proceeding in a sequence of -Michael/aldol/annulation reactions. This highly diastereo- and enantioselective reaction is realized by employing enantioselective bifunctional catalysis and exhibits a broad substrate scope and excellent functional group tolerance.

Classification of Polish Natural Bee Honeys Based on Their Chemical Composition.

The targeted quantitative NMR (qNMR) approach is a powerful analytical tool, which can be applied to classify and/or determine the authenticity of honey samples. In our study, this technique was used to determine the chemical profiles of different types of Polish honey samples, featured by variable contents of main sugars, free amino acids, and 5-(hydroxymethyl)furfural. One-way analysis of variance (ANOVA) was performed on concentrations of selected compounds to determine significant differences in their levels between all types of honey.

Visible-light synthesis of 4-substituted-chroman-2-ones and 2-substituted-chroman-4-ones doubly decarboxylative Giese reaction.

Doubly decarboxylative, photoredox synthesis of 4-substituted-chroman-2-ones and 2-substituted-chroman-4-ones is described. The reaction involves two independent decarboxylation processes: the first one initiating the cycle and the second completing the process. Visible light, photoredox catalyst, base, anhydrous solvent and inert atmosphere constitute the key parameters for the success of the developed transformation.

Dearomative Michael addition involving enals and 2-nitrobenzofurans realized under NHC-catalysis.

In this manuscript, the first enantioselective dearomative Michael addition between α,β-unsaturated aldehydes and 2-nitrobenzofurans realized under N-heterocyclic carbene activation has been described. The reaction proceeds addition of homoenolate to Michael acceptors leading to the formation of biologically important heterocycles with high yields and stereoselectivities. Their functionalization potential has been confirmed in selected, diastereoselective transformations.

5-Substituted-furan-2(3)-ones in [8 + 2]-Cycloaddition with 8,8-Dicyanoheptafulvene.

This study demonstrates the use of organocatalytic Brønsted base activation of 5-substituted-furan-2(3)-ones to generate 2π-components for the diastereoselective [8 + 2]-cycloaddition involving 8,8-dicyanoheptafulvene as an 8π-component. The use of dienolates in a higher-order cycloaddition reaction leads to the formation of biologically relevant polycyclic products bearing a γ-butyrolactone structural motif, thus broadening the synthetic potential of Brønsted base activated higher-order cycloadditions.

Differentiating Catalysis in the Dearomative [4 + 2]-Cycloaddition Involving Enals and Heteroaromatic Aldehydes.

In this paper, the application of differentiating catalysis in the [4 + 2]-cycloaddition between 2-alkyl-3-formylheteroarenes and α,β-unsaturated aldehydes is described. Within the developed approach, the same aminocatalyst is employed for the independent activation of both starting materials, differentiating their properties via LUMO-lowering and HOMO-rising principles. By the combination of dearomative dienamine activation with iminium ion chemistry high enantio- and diastereoselectivity of the doubly asymmetric process was accomplished.

Asymmetric Dearomative (3+2)-Cycloaddition Involving Nitro-Substituted Benzoheteroarenes under H-Bonding Catalysis.

In our studies, the organocatalytic 1,3-dipolar cycloaddition between 2-nitrobenzofurans or 2-nitrobenzothiophene and -2,2,2-trifluoroethyl-substituted isatin imines has been developed. The reaction has been realized by employing bifunctional organocatalysis, with the use of squaramide derivative being crucial for the stereochemical efficiency of the process. The usefulness of the cycloadducts obtained has been confirmed in selected transformations, including aromative and non-aromative removal of the nitro group.

Vinylogous hydrazone strategy for the organocatalytic alkylation of heteroaromatic derivatives.

A new umpolung approach for the asymmetric Friedel-Crafts-type alkylation of electron-poor heteroaromatic systems has been developed. It is based on the vinylogous reactivity of hydrazones derived from heteroaromatic aldehydes. The donating effect of the hydrazone moiety can be efficiently transferred over the heteroaromatic system activating it towards an asymmetric Friedel-Crafts reaction with α,β-unsaturated aldehydes realized under aminocatalytic conditions.

Solid-Phase Synthesis of an Insect Pyrokinin Analog Incorporating an Imidazoline Ring as Isosteric Replacement of a Peptide Bond.

A facile solid-phase synthetic method for incorporating the imidazoline ring motif, a surrogate for a peptide bond, into bioactive peptides is reported. The example described is the synthesis of an imidazoline peptidomimetic analog of an insect pyrokinin neuropeptide via a cyclization reaction of an iminium salt generated from the preceding amino acid and 2,4-diaminopropanoic acid (Dap).

The First Application of H NMR Spectroscopy for the Assessment of the Authenticity of Perfumes.

The manufacture of counterfeit goods is one of the world's largest underground businesses and is rapidly growing. Counterfeits can lead not only to the loss of profit for honest producers but also have a negative impact on consumers who pay excessive prices for poor quality goods that may result in health or safety problems. The perfume industry is constantly vulnerable to counterfeits, particularly in the fast developing market of "smell-alike" designer-inspired perfumes because these prompt the identification of the methods that classify their quality.

1,3,4-Thiadiazoles Effectively Inhibit Proliferation of .

Congenital and acquired toxoplasmosis caused by the food- and water-born parasite () is one of the most prevalent zoonotic infection of global importance. is an obligate intracellular parasite with limited capacity for extracellular survival, thus a successful, efficient and robust host cell invasion process is crucial for its survival, proliferation and transmission. In this study, we screened a series of novel 1,3,4-thiadiazole-2-halophenylamines functionalized at the C5 position with the imidazole ring (-) for their effects on host cell invasion and proliferation.

Hydroxyl-group-activated azomethine ylides in organocatalytic H-bond-assisted 1,3-dipolar cycloadditions and beyond.

1,3-Dipolar cycloaddition constitutes a powerful means for the synthesis of five-membered heterocycles. Recently, the potential of this field of chemistry has been expanded by the employment of organocatalytic activation strategies. One group of substrates, namely imines derived from salicylaldehydes, is particularly useful.

Enantioselective H-bond-directed vinylogous iminium ion strategy for the functionalization of vinyl-substituted heteroaryl aldehydes.

In this work the first H-bond-directed vinylogous iminium ion strategy has been developed as a convenient strategy for the γ,δ-functionalization of vinyl-substituted heteroaromatic aldehydes. Their reaction with α-mercaptoketones proceeds in a cascade manner involving 1,6-addition followed by intramolecular aldol reaction. Excellent stereoselectivities have been obtained as a result of the H-bond interactions controlling the outcome of the cyclization step.

The Application of NMR Spectroscopy and Chemometrics in Authentication of Spices.

Spices and herbs are among the most commonly adulterated food types. This is because spices are widely used to process food. Spices not only enhance the flavor and taste of food, but they are also sources of numerous bioactive compounds that are significantly beneficial for health.

Asymmetric vinylogous Michael addition of 5-substituted-furan-2(3)-ones to an α,β-unsaturated-γ-lactam.

The manuscript describes an utilization of 5-substituted-furan-2(3H)-ones as pronucleophiles in an asymmetric vinylogous Michael addition to an α,β-unsaturated-γ-lactam, thus leading to hybrid molecules possessing γ-lactam and butenolide structural motifs. The transformation utilizes two potentially vinylogous pronucleophiles and has been realized by simultaneous activation of both substrates by a bifunctional organocatalyst derived from a cinchona alkaloid. Reaction occurs in a highly enantio- and diastereoselective manner and the synthetic potential of the target products has been confirmed in stereoselective transformations.

Doubly vinylogous and doubly rearomative functionalization of 2-alkyl-3-furfurals.

The manuscript describes a straightforward functionalization of 2-alkyl-3-furfurals via simple aminocatalytic conjugate addition. The reaction proceeds through the formation of dearomatized dienamine-like intermediate that undergoes 1,6-addition to 4-alkylidene-2,6-dialkylcyclohexa-2,5-dienones. This process can be described as doubly rearomative as it proceeds with the re-formation of both furan and phenyl aromatic moieties.

Asymmetric Synthesis of [2.2.2]-Bicyclic Lactones via All-Carbon Inverse-Electron-Demand Diels-Alder Reaction.

In this paper, a new cycloaddition between α,β-unsaturated aldehydes and coumalates realized under dienamine activation has been described. The reaction proceeds regioselectively with the distal double bond of the dienamine system acting as electron-rich dienophile. It leads to the formation of biologically relevant [2.

Allylic-Allylic Alkylation with 3,5-Dimethyl-4-nitroisoxazole: A Route to Dicarboxylic Acid Derivatives.

In this work, the first application of 3,5-dimethyl-4-nitroisoxazole as a vinylogous pronucleophile in the allylic-allylic alkylation of Morita-Baylis-Hillman (MBH) carbonates is described. The reaction has been realized under nucleophilic catalysis conditions with dimeric cinchona alkaloids, providing excellent enantiocontrol of the process. The usefulness of the products thus obtained has been confirmed in selected chemoselective reactions.

The influence of experimental parameters on quantitative deuterium measurements for ethyl alcohols of different origin.

Background: Quantitative determination with site-specific natural isotope fractionation nuclear magnetic resonance (SNIF-NMR) has been exploited widely in detecting adulteration and for the classification of natural products by their geographical origin.

Results: We compared isotopic parameters such as deuterium / hydrogen (D/H) site specific ratios and the R parameter for alcoholic beverages, obtained using (i) a 500 MHz spectrometer equipped with a dedicated probe for isotopic measurements, and (ii) a 700 MHz spectrometer equipped with a standard probe. The factors affecting the accuracy and precision of quantitative NMR with the second instrument have been explored.