Alkane Derivatives Research Articles

Competition of C–F, C–S, and S–F Bond Activation in SF5CF3 Using N‐Heterocyclic Olefins Derivatives: A Computational Study

ABSTRACTSF5CF3, commonly recognized as a potent greenhouse gas, has recently emerged as a valuable source of fluoride functional groups. Despite its traditional role, recent studies have highlighted its potential applications beyond its environmental implications. However, investigations into its reactivity remain limited, particularly regarding the activation of its constituent bonds. In this study, we conducted a comprehensive computational analysis to elucidate the competition among C–F, C–S, and S–F bond activations within SF5CF3 utilizing N‐heterocyclic olefin derivatives. Our investigations shed light on the underlying mechanisms of bond activation, revealing a preference for the activation of the S–F bond in SF5CF3 by both NHOs and mNHOs. Specifically, we observed a Gibbs free energy barrier (ΔG≠) ranging from 24.90 to 25.77 kcal/mol in the case of mNHOs, indicating a favorable energetics for this process.

Iron-Mediated Segment Coupling of Alkenols with Acceptors via C-C Radical Translocation and Remote Oxidative 1,5/6-Hydrogen Atom Transfer.

Iron-mediated segment coupling followed by oxidative 1,5/6-hydrogen atom transfer (HAT) for synthesis of ε-oxo alkene derivatives is developed. This transformation involved translocation of the radical from H-to-C-to-C-to-C followed by the oxidation under MHAT conditions providing rapid access to 1,6/1,7-keto functionalized esters/ketone/sulfones/phosphonates/arenes. The different outcomes of coupling with acceptors could be explained by bond dissociation energies (BDEs), and mechanistic insights were gained through control experiments, including deuterium labeling studies.

Application of Hydroxyaromatic Aldehydes in Ultra-Efficient and Metal-Free Photocatalytic E→Z Isomerization of Olefin.

The strategy of photocatalyzed E→Z isomerization of olefins to access thermodynamically less stable Z-alkenes has recently received considerable attention. Here, we have discovered a sensitizer of hydroxyaromatic aldehyde that can rapidly achieve olefin E→Z isomerization under blue light irradiation. Notably, 2-hydroxybenzene-1,3,5-tricarbaldehyde, when assisted by blue light, can achieve efficient and selective conversion within just 5 minutes (Z/E=92 : 8). The reaction can be successfully scaled up to gram scale, and exhibits remarkable reactivity toward various derivatives of ethyl cinnamate (27 examples) and other olefins. Furthermore, the former can be directly cyclized by a hydroxyl derivative to produce 4-substituted coumarin. The prominent preponderance of this method includes being metal-free, efficient, convenient, no by-products and achieving high selectivity. Correlation of sensitizer triplet energy (ET) and preliminary mechanistic experiments indicate that the accomplishment of this reaction is based on the selective excitation mechanism.

Ruthenium Complexes of Phenylbenzothiazole‐Quinoline based Ligands for Selective α‐Olefination of Methylazaarenes

This report describes synthesis of a new ligand (E)‐N‐(4‐(benzo[d]thiazol‐2‐yl)phenyl)‐1‐(quinolin‐2‐yl)methanimine (L1) and its three ruthenium(II) arene complexes with [RuCl2(p‐cymene)]2 (C1), [RuCl2(benzene)]2 (C2), and [RuCl2(hmb)]2 [hmb = hexamethylbenzene] (C3). The new ligand and complexes were characterized with the help of standard spectroscopic and analytical techniques like 1H and 13C{1H} Nuclear Magnetic Resonance (NMR), Fourier transform infrared (FTIR), High‐resolution mass spectrometry (HRMS), UV‐Visible, cyclic voltammetry, and elemental analysis. The structure of ruthenium complex (C1) and its binding mode with ligand were authenticated with the help of single crystal X‐ray diffraction. The ruthenium arene complexes (C1‐C3) were used as a catalyst for the α‐olefination of Methylazaarenes. First, methylazaarenes were reacted with alcohols under optimized reaction conditions to produce α‐olefinated products (up to 66%) selectively. Among the three ruthenium complexes, C1 demonstrated the highest yield of olefinated products with 5 mol% catalyst loading. Finally, selected olefin derivatives were tested for their inhibitory potential towards the aggregation of amyloid‐b‐40 (Aβ40) peptide relevant to Alzheimer’s disease. Overall, these complexes are promising catalysts for organic transformations, and the synthesized α‐olefinated derivatives could have potential applications for the development of therapeutic agents for Alzheimer’s disease.

Stabilization and Surface Functionalization of Palladium Disulfide Nanoparticles with Acetylene Derivatives.

Metal chalcogenide nanoparticles have been attracting extensive attention in diverse fields. Traditionally these nanoparticles are stabilized by organic ligands such as thiols and amines involving nonconjugated core-ligand interfacial interactions. In the present study, a facile wet-chemistry method is described for the synthesis of palladium disulfide (PdS2) nanoparticles capped with acetylene derivatives. Spectroscopic and electrochemical measurements suggest that conjugated Pd-C≡ linkages are formed at the core-ligand interface and facilitate electronic coupling and hence manipulation of the nanoparticle optical and electronic properties. The unique interfacial linkages also allow further functionalization of the nanoparticles by metathesis reaction with olefin derivatives, as manifested in the reaction with vinylferrocene. This research opens new avenues for the structural engineering and functionalization of metal chalcogenide nanoparticles.

Photoinduced Ligand-to-Copper Charge Transfer for Aryl Decarboxylative Allylation, Thiolation, and Bromination.

Herein, aryl decarboxylative allylation, thiolation, and bromination reactions via photoinduced ligand-to-copper charge transfer are described. Utilizing inexpensive copper metal, the transformations of various aryl carboxylic acids enable the rapid synthesis of the corresponding alkene, thioether, and aryl bromide derivatives under visible light irradiation, which offers significant synthetic value. The reaction conditions are mild and straightforward, exhibiting a broad substrate compatibility. Furthermore, this method can be applied for the late-stage modification of complex drug molecules.

Synthetic Methods and Pharmacological Potentials of Isothiocyanate Derivatives

The present review deals with different synthetic methods of isothiocyanates, including alcohols, aryl chlorides, primary amines, carboxylic acid or carboxylic acid derivatives, cleavage of heterocyclic compounds, and alkene derivatives as a starting material. Furthermore, the thermal rearrangement of thiocyanate, decomposition of thiourea derivatives, and natural isothiocyanates are discussed. It also includes the chemical reaction of isothiocyanates derivatives, such as reaction with alkenes and aromatic compounds, addition of water and amine derivatives, reaction with amino alcohol derivatives, reaction with amino acids and their derivatives, reaction with hydrazine and acid hydrazide derivatives, and miscellaneous reactions. In addition, this review summarizes different pharmaceutical applications of isothiocyanate derivatives, such as anticancer, antimicrobial, antioxidant, and anti-inflammatory activities.

Rapid point-of-care breath test predicts breast cancer and abnormal mammograms in symptomatic women

Previous studies have reported volatile organic compounds (VOCs) in the breath as biomarkers of breast cancer. These biomarkers may be derived from cancer-associated fibroblasts, in which oxidative stress degrades polyunsaturated fatty acids to volatile alkanes and methylated alkane derivatives that are excreted in the breath. We evaluated a rapid point-of-care test for breath VOC biomarkers as predictors of breast cancer and abnormal mammograms.&#xD;Methods: We studied 593 women aged ≥ 18 yr referred to three sites for mammography for a symptomatic breast-related concern (e.g. breast mass, nipple discharge). A rapid point-of-care breath testing system collected and concentrated alveolar breath VOCs on a sorbent trap and analyzed them with gas chromatography and surface acoustic wave detection in < 6 min. Breath VOC chromatograms were randomly assigned to a training set or to a validation set. Monte Carlo analysis identified significant breath VOC biomarkers of breast cancer and abnormal mammograms in the training set, and these biomarkers were incorporated into a multivariate algorithm to predict disease in the validation set. &#xD;Results: Prediction of breast cancer: 50 women had biopsy-proven breast cancer (invasive cancer 41, ductal non-invasive cancer 9)&#xD;Unsplit data set: Breath VOCs identified breast cancer with 83% accuracy (area under curve of receiver operating characteristic), 82% sensitivity and 77.1% specificity.&#xD;Split data sets: Training set breath VOCs identified breast cancer with 80.3% accuracy, 84% sensitivity and 74.3% specificity. Corresponding values in the validation set were 68%% accuracy, 72.4% sensitivity and 61.5% specificity.&#xD;Prediction of BIRADS 4 and 5 mammograms (versus BIRADS 1, 2 and 3): &#xD;Unsplit data set: Breath VOCs identified abnormal mammograms with 76.2% accuracy.&#xD;Split data sets: Breath VOCs identified abnormal mammograms with 74.2% accuracy, 73.3% sensitivity and 60% specificity. Corresponding values in the validation set were 60.5% accuracy, 64.2% sensitivity and 51% specificity.&#xD;Conclusions: A rapid point-of-care test for breath VOC biomarkers predicted risk of breast cancer and abnormal mammograms in women with breast-related symptoms.&#xD;&#xD.

PPh3-Promoted Direct Deoxygenation of Epoxides to Alkenes.

Deoxygenation of epoxides into alkenes is one of the most important strategies in organic synthesis, biomass conversions, and medicinal chemistry. Although metal-catalyzed direct deoxygenation provides one of the most commonly encountered protocols for the conversion of epoxides to alkenes, the requirement of expensive catalysts and extra reductants has largely limited their universal applicability. Herein, we report an efficient PPh3-promoted metal-free strategy for deoxygenation of epoxides to generate alkene derivatives. The success of deoxyalkenylation of epoxides bearing a wide range of functional groups to give terminal, 1,1-disubstituted, and 1,2-disubstituted alkenes manifests the powerfulness and versatility of this strategy. Moreover, gram-scale synthesis with excellent yield and modification of biologically active molecules exemplifies its generality and practicability.

Ir-Catalyzed Synthesis of β-Substituted α-Amino Acids Using Alkene and Glycine Derivatives

Ir-Catalyzed Synthesis of β-Substituted α-Amino Acids Using Alkene and Glycine Derivatives

A novel Fe(III) and 2-amino-perimidinium based hybrid material catalyzed friedel–Crafts type hydroarylation of alkynes: Scope and mechanism

A new inorganic-organic hybrid material with the structural formula (C51H66N9)3[FeCl4]·2Cl consisting of iron(III) center, 2-amino-perimidinium ligand and free chloride ions was synthesized. In addition, the compound was characterized by single-crystal X-ray diffraction and Fourier-transform infrared spectroscopy techniques. The structural arrangements and hydrogen bonding interactions in the compound were studied and successfully employed in the catalytic hydroarylation of alkynes and arenes to produce the corresponding 1,1-diaryl alkene derivatives. Gratifyingly, when nitromethane was employed as a solvent, the title compound displayed excellent catalytic activity with moderate to high conversions. Stoichiometric reactions and experimental data both provided key evidence in support of the reaction mechanism.

Photodriven Radical Perfluoroalkylation-Thiolation of Unactivated Alkenes Enabled by Electron Donor-Acceptor Complex.

A clean and direct three-component radical 1,2-difunctionalization of various alkenes with perfluoroalkyl iodides and thiosulfonates enabled by the electron donor-acceptor complex has been developed under light illumination at room temperature. The approach offers a convenient and environmentally friendly route for the simultaneous incorporation of Csp3-Rf and Csp3-S bonds, affording valuable polyfunctionalized alkane derivatives containing fluorine and sulfur in satisfactory yields. Consequently, this methodology holds significant value and practicality in the field of organic synthesis.

Serum albumin hydrogels designed by protein Re-association for self-powered intelligent interactive systems

Advancements in protein structural engineering have made it possible to design protein materials that can mediate between humans and intelligent systems, manifesting a combination of characteristics such as elastic recovery, electrical conductivity, and stability. This work describes the design of a hydrogel using bovine serum albumin (BSA), based on protein-protein interactions and sulfhydryl-alkene click reactions. The multiple α-helices of BSA were intertwined together by the multi-armed olefin derivatives, acting like Lego blocks to form a gel network and locking in bound water and ions, thus imparting mechanical recovery characteristics (demonstrating 80 % recovery after the compressive strain and 638 % after tensile strain), electrical conductivity, resistance to freezing (maintaining mechanical properties after being frozen at -20 °C for 48 h), biocompatibility (the cell viability of mouse pre-osteoblast-like cells in the hydrogels was 97.5 %), antimicrobial properties, and biodegradability to the BSA hydrogels. A multi-channel wireless signal acquisition system based on BSA hydrogel devices designed for bioenergy conversion and harvesting was developed for the real-time detection of human motion along with a human-mechanics interaction system for manipulating robotic gestures with simple human finger movements. This restructuring of the BSA structure represents a significant advancement in the systematic exploration of protein structures and the development of protein materials. These applications serve as a secure bridge between humans and energy storage devices.

Bicyclo[m.n.k]alkane Building Blocks as Promising Benzene and Cycloalkane Isosteres: Multigram Synthesis, Physicochemical and Structural Characterization.

Electrophilic double bond functionalization - intramolecular enolate alkylation sequence was used to obtain a series of bridged and fused bicyclo[m.n.k]alkane derivatives (i. e., bicyclo[4.1.1]octanes, bicyclo[2.2.1]heptanes, bicyclo[3.2.1]octanes, bicyclo[3.1.0]hexanes, and bicyclo[4.2.0]heptanes). The scope and limitations of the method were established, and applicability to the multigram synthesis of target bicyclic compounds was illustrated. Using the developed protocols, over 50 mono- and bifunctional building blocks relevant to medicinal chemistry were prepared. The synthesized compounds are promising isosteres of benzene and cycloalkane rings, which is confirmed by their physicochemical and structural characterization (pKa , LogP, and exit vector parameters (EVP)). "Rules of thumb" for the upcoming isosteric replacement studies were proposed.

Palladium Complexes with N,O‐Bidentate Ligands Based on N‐Oxide Units from Cyclic Secondary Amines: Synthesis and Catalytic Application in Mizoroki‐Heck Reaction

Comprehensive SummaryPalladium‐catalyzed Mizoroki‐Heck reaction is a powerful and efficient method for construction of Csp2–Csp2 bonds. Herein, four palladium complexes (I—IV) with N,O‐bidentate ligands (L1—L4) based on N‐oxide units from cyclic secondary amines were easily synthesized and successfully applied in Mizoroki‐Heck reaction of aryl bromides with electron‐deficient olefins. X‐ray diffraction analyses indicated the palladium(II) atom of II took the distorted square planar geometry and was four‐coordinated by nitrogen and oxygen atoms from two ligands (L2). Two free chloride ions were presented as counter anions in complex II. But the palladium(II) center of IV was coordinated by nitrogen and oxygen atoms from one ligand (L4) as well as two chlorine atoms, which exhibited the nearly square‐planar geometry. The study on catalytic properties of palladium complexes revealed that complex II exhibited high activity superior to the other complexes. The coupling reactions of a series of aryl bromides and olefin derivatives proceeded in the presence of 2—5 mol% palladium complex II, giving the desired products in good to excellent yields. The advantages of this method such as good compatibility of functional groups, high yields, and short reaction times made it more attractive for constructing Csp2–Csp2 bonds in the synthesis of functional molecules and materials.

Thermal Conductivity of Liquid cis- and trans-Isomers of Hyrofluorochlorine Derivatives of Olefins on the Saturation Line

Thermal Conductivity of Liquid cis- and trans-Isomers of Hyrofluorochlorine Derivatives of Olefins on the Saturation Line

Demethylenative cyclization of 1,7-enynes using α-amino radicals as a traceless initiator enabled by Cu(I)-photosensitizers.

A rare type of demethylenative intramolecular cyclization of 1,7-enynes to access quinoline-2-(1H)-ones has been successfully developed under the catalysis of P/N-heteroleptic Cu(I)-photosensitizers. Preliminary mechanistic experiments revealed that the key to the success of this protocol lay in the α-amino radical addition-triggered tandem process of intramolecular radical cyclization/1,5-HAT/β-fragmentation. This protocol provides a new avenue for the deconstructive cyclization of alkene derivatives.

A new method for synthesizing terminal olefins from esters using the Corey-Chaykovsky reagent.

A new method for the synthesis of terminal olefins was developed through the reaction of the Corey-Chaykovsky reagent (dimethyl-sulfonium methylide) with readily available esters. After the domino process of nucleophilic addition, elimination and rearrangement in one pot, the terminal olefins were synthesized in high yields (up to 84%) under mild conditions. The synthetic method was well tolerated by many functional groups and a new route for the synthesis of various terminal olefin derivatives is provided. In the end, a possible reaction mechanism is proposed, which is supported by DFT calculations.

The chemical composition of the aerial parts essential oils of four Andryala species (Asteraceae) growing wild in Morocco

Andryala (Asteraceae: Cichorieae) is a little-known Mediterranean-Macaronesian genus whose taxonomy is very much in need of revision. In the present study, the chemical composition of the essential oils (EOs) from aerial parts of as many Andryala species, A. integrifolia, A. cossyrensis, and A. rothia, never studied before, and of A. pinnatifida subsp. mogadorensis, all collected in Morocco, was evaluated by GC-MS. The main components of the EOs of A. integrifolia and A. pinnatifida subsp. mogadorensis were organic acid compounds (41.10% and 43.52%, respectively), whereas A. cossyrensis, and A. rothia were shown to be rich in alkane derivatives (43.10% and 34.29%, respectively). Aldehydic compounds were the second class of metabolites in A. integrifolia and A. rothia (26.67% and 21.91%, respectively), whereas terpenoids, represented in all the four species in limited amounts, were more abundant only in A. pinnatifida subsp. mogadorensis (9.90%) and A. rothia (11.79%) species.

New Correlation Model of Thermal Conductivity of Liquid Hydrofluorochloro Derivatives of Olefins, Hydrofluorocarbons, and Hydrochlorofluorocarbons

New Correlation Model of Thermal Conductivity of Liquid Hydrofluorochloro Derivatives of Olefins, Hydrofluorocarbons, and Hydrochlorofluorocarbons