Alkane Derivatives Research Articles

Common Effects of Incorporatedn-Alkane Derivatives on Molecular Packing and Phase Behavior of DPPC Bilayers

Effects of nine incorporated n-alkane derivatives on molecular packing and phase behavior of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) bilayers were investigated using wide angle X-ray dif...

Photoredox‐Initiated 1,2‐Difunctionalization of Alkenes with N‐Chloro S‐Fluoroalkyl Sulfoximines

AbstractWe describe herein the photoredox‐initiated 1,2‐difunctionalization of alkene derivatives with N‐chloro S‐fluoroalkyl sulfoximines yielding novel fluoroalkyl sulfoximine scaffolds. The reaction is proposed to proceed through an atom‐transfer radical addition (ATRA) mechanism involving the generation of fluorinated nitrogen‐centered sulfoximidoyl radicals.magnified image

Synthesis of Bis-Cycloborate Olefin and Butatriene Derivatives through the Reduction of Alkynyl-Bridged Diboryl Compounds.

A series of bis-cycloborate olefin and butatriene derivatives were synthesized from alkynyl-bridged diboryl compounds using a simple reduction strategy. In the reduction route of 1,2-bis[2-(dimesitylboranyl)phenyl]ethyne (1), bis-cycloborate olefin (4) to diborate-bridged stilbene (5) can be obtained selectively by varying the reaction temperature. In addition, a thermal isomerization from 4 to 5 was found as a result of the rearrangement of double bonds. The generality of this reaction was further verified in similar reduction reactions. In the direduction of 1,2-bis[8-(dimesitylboranyl)naphthalen-1-yl]ethyne (2), the bis-cycloborate olefin (6) was isolated in high yield and demonstrated no thermal isomerization. In the two-electron reduction of 1,8-bis{[2-(dimesitylboranyl)phenyl]ethynyl}naphthalene (3), the bis-cycloborate butatriene (7) was obtained unexpectedly because of the departure of the naphthyl group. When using Na as the reductant and diethyl ether as the solvent, 1,2-bis[( Z)-2-(dimesitylboranyl)benzylidene]-1,2-dihydroacenaphthylene (8) was isolated after adding 1 or 2 drops of H2O to the reduction reaction filtrates. Meanwhile, the related mechanisms for radical cyclization, thermal isomerization, and formation of bis-cycloborate butatriene were also discussed.

1,2-Dihaloalkenes in Metal-Catalyzed Reactions

1,2-Dihaloalkenes readily undergo simultaneous or sequential difunctionalization through transition-metal-catalyzed reactions, which makes them attractive building blocks for complex unsaturated motifs. This review summarizes recent applications of such transformations in C–C and C–heteroatom bond forming processes. The facile synthesis of stereodefined alkene derivatives, as well as aromatic and heteroatomic­ compounds, from 1,2-dihaloalkenes is thus outlined.1 Introduction2 Synthesis of 1,2-Dihaloalkenes3 C–C Bond Forming Reactions4 C–Heteroatom Bond Forming Reactions5 Conclusion

Reaction Mechanisms of 2-Butanol Dehydration over a Phosphorus-Containing Activated Carbon Acid Catalyst

The reaction mechanisms for the carbon-based acid catalytic conversion of 2-butanol into dehydration and dehydrogenation products (alkene derivatives and ketone) have been theoretically studied by assuming that the acid site is a dihydrogen phosphate group bonded to one of the carbon atoms of the central ring of anthracene. The structural model of the active site of the surface of the catalyst reproduces properly the experimental results. Kinetic and thermodynamic magnitudes have been obtained by using standard expressions of Eyring’s transition-state theory and statistical thermodynamics. Interpretation of the calculations (molecular charges, geometries, and energies) demonstrates that the dehydration reaction process is an E2 mechanism (one-step reaction) with strong character of E1 mechanism (two-step reaction). The study of the mechanism has been carried out by applying density functional theory with the metaexchange–correlation functional M06-2X. The reactants and products connected by the respective...

Discovery of a novel olefin derivative as a highly potent and selective acetyl-CoA carboxylase 2 inhibitor with in vivo efficacy

Novel acetyl-CoA carboxylase 2 (ACC2) selective inhibitors were identified by the conversion of the alkyne unit of A-908292 to the olefin linker. Modification of the center and left part of the lead compound 1b improved the ACC2 inhibitory activity and CYP450 inhibition profile, and afforded a highly selective ACC2 inhibitor 2e which showed in vivo efficacy in C57BL/6 mice.

Sequential Condensation and Hydrodeoxygenation Reaction of Furfural-Acetone Adduct over Mix Catalysts Ni/SiO<sub>2</sub> and Cu/SiO<sub>2</sub> in Water

Sequential condensation and hydrodeoxygenation reaction were perform using autoclave batch reactor in the presence of water as a solvent. The condensation of furfural and acetone was performed using MgO catalyst followed by hydrodeoxygenation using mix catalyst Ni/SiO2 and Cu/SiO2. The catalyst was prepared by wet-impregnation method and analyzed by XRD, SEM-EDX as well as BET surface. Condensation of furfural and acetone in 1:2 mol ratio was carried out by reflux gave 4-(2-furyl)-3-buten-2-one and 1,5-bis-(2-furanyl)-1,4-pentadien-3-one. The condensation product was then subjected for hydrodeoxygenation using batch reactor, catalyzed by mixed Ni/SiO2 and Cu/SiO2 at 150 and 180 °C for 2 h. The product identified as alkane derivatives with the conversion at 38.83 and 50.35%, respectively. The selectivity of hydrocarbon is 61.39% at 150 °C and 16.55% at 180 °C. Increasing the reaction temperature to 200 °C did not give any products except the recovery of the precursor. It showed that higher temperature enhanced the catalyst activity but the selectivity is controlled by low reaction temperature.

Elucidating the antimicrobial mechanisms of colistin sulfate on Mycobacterium tuberculosis using metabolomics

Considering the disadvantageous of first line anti-tuberculosis (TB) drugs, including poor patient adherence, drug side effects, the long treatment duration and rapidly increasing microbe resistance, alternative treatment strategies are needed. Colistin sulfate (CS), a polymyxin antibiotic considered a last-resort antibiotics for treating multidrug-resistant Pseudomonas aeruginosa, Klebsiella pneumoniae, and Acinetobacter, has antimicrobial activity towards mycobacteria, and could serve as a possible anti-TB drug.Using GCxGC-TOFMS metabolomics, we compared the metabolic profiles of Mycobacterium tuberculosis (Mtb) cultured in the presence and absence of CS, to elucidate the mechanisms by which this drug may exert its antimicrobial effects.The principal component analysis of the metabolite data indicated significant variation in the underlying metabolite profiles of the groups. Those metabolites best explaining this differentiation, were acetic acid, and cell wall associated methylated and unmethylated fatty acids, and their alcohol and alkane derivatives. The elevated glucose levels, and various glyoxylate and glycerolipid metabolic intermediates, indicates an elevated flux in these metabolic pathways.Since all the metabolites identified in the colistin treated Mtb indicates an increase in fatty acid synthesis and cell wall repair, it can be concluded that CS acts by disrupting the cell wall in Mtb, confirming a similar drug action to other organisms.

Dirhodium(II)-Catalyzed (3 + 2) Cycloaddition of the N-Arylaminocyclopropane with Alkene Derivatives.

Several (3 + 2) cycloaddition reactions catalyzed by dirhodium(II) complexes between N-arylaminocyclopropane and alkenes derivative have been developed. Preliminary mechanism studies suggest that dirhodium(II) complexes may decrease the bond-dissociation energy (BDE) of the N-H bond of N-arylaminocyclopropanes for N-H bond activation, thus facilitating the formation of N-centered radicals by loss of a hydrogen radical.

Synthesis of 2-Azabicyclo[n.2.0]alkane-Derived Building Blocks

An approach to 2-azabicyclo[n.2.0]alkane derivatives (n = 1, 2), which relies on a tandem Strecker reaction–intramolecular nucleophilic cyclization (STRINC) sequence of the corresponding 2-(ω-chloroalkyl)cyclobutanones (in turn prepared by [2+2] cycloaddition of keteniminium salts and ethylene) is described. The utility of the method is demonstrated by multigram syntheses of bicyclic proline analogues, monoprotected diamines, as well as parent 2-azabicyclo[4.2.0]octane.

New type of highly active chromium(III) catalysts containing both organic cations and anions designed for polymerization of beta-olefin derivatives

The new type of catalysts designed for the olefin derivatives polymerization has been synthetized. The novel catalysts are chromium(III) salt type complexes composed of both organic cation and anion, i.e. [Cr(dipic)2][Cr(bipy)(dipic)H2O]∙2H2O and [Cr(dipic)2]Hdmbipy∙2.5 H2O. The compositions of these complexes have been confirmed by a number of instrumental methods including NMR, IR, UV-Vis, MS and elemental analysis ones. Moreover, the crystal structures of these novel catalysts were determined and reported. Furthermore, the [Cr(dipic)2][Cr(bipy)(dipic)H2O]∙2H2O and [Cr(dipic)2]Hdmbipy∙2.5H2O complexes have been studied towards their catalytic activity, after the activation by MMAO (modified methylaluminoxane), in the case of 2-chloro-2-propen-1-ol polymerization at 21 °C and atmospheric pressure. It has been found that novel catalysts, [Cr(dipic)2][Cr(bipy)(dipic)H2O]∙2H2O and [Cr(dipic)2]Hdmbipy∙2.5 H2O, exhibit a very high catalytic activity in the process of the polymerization of the beta-olefin derivatives. The products of a such catalyzed polymerization are the poly(allyl alcohol) derivatives.

Palladium‐Catalyzed Regioselective Three‐Component Cascade Bisthiolation of Terminal Alkynes

AbstractAn efficient and novel NHC(N‐heterocyclic carbene)‐palladium‐catalyzed three‐component cascade bisthiolation of terminal alkynes, K2S (potassium sulfide) and diaryliodonium salts for the assembly of functionalized (Z)‐1,2‐bis(arylthio)alkene derivatives has been accomplished for the first time. This unique observation features a broad substrate scope, excellent functional‐group tolerance, and high regioselectivity. Especially, an arylthiolate anion from diaryliodonium salts and potassium sulfide was proposed as the key intermediate in the catalytic cycle.magnified image

Characterization of Volatile Components of Eight FengHuang Dancong Manufactured Teas and Fresh Leaves by HS-SPME Coupled with GC-MS

FengHuang Dancong tea is famous for its excellent aroma quality. In order to characterize the volatile components in different aroma types of FengHuang Dancong tea, both fresh leaves and manufactured teas of seven well-known aroma types and their ancestor variety, which were harvested from the same places and manufactured using the same procedure, were investigated using headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS). Results indicated that the volatile composition and contents of manufactured teas and fresh leaves, including HuangZhi, XingRen, GuiHua, MiLan, JiangHua, YuLan YeLai and Fenghuang Shuixian, were obviously different. Linalool, (E)-2-hexenal, cis-3-hexenyl acetate, linalool oxide, methyl salicylate, geraniol, and nerolidol were the major volatile components in fresh leaves, and their total relative contents ranged from 78.44-90.07%. But in manufactured teas, hotrienol, linalool, β-myrcene, D-limonene, 1-ethyl-1H-pyrrole-2-carboxaldehyde, β-ocimene, linalool oxide, benzyl nitrile, indole, jasmone, and nerolidol were the major volatile components, ranged from 60.12-93.97%. Although there were some similarities in the aroma composition and content among the manufactured teas of different aroma types, each type had unique aroma characteristics. The obvious difference between FengHuang Shuixian and other aroma types of manufactured teas may be due to the higher content of alkene and pyrrole derivatives and lower content of alcohols, especial terpene alcohols. Furthermore, the correlations between manufactured teas and the fresh leaves indicated that the volatile compounds profile of fresh leaves may affect the aroma quality of the manufactured tea. This study provided a comprehensive comparison of the volatile profile in different aroma types of Fenghuang Dancong tea, which is a scientific foundation for further quality assessment of Fenghuang Dancong variety in the future.

One-Step Condensation and Hydrogenation of Furfural-Acetone Using Mixed and Single Catalyst Based on Ni/M-Oxide [M=Al; Mg

Modification of furfural by condensation and hydrogenation reaction is a promising approach to produce higher alkane derivatives (C8-C13) as diesel fraction. This research investigated the catalytic activity of Ni/MgO as bifunctional catalyst compared with MgO-Ni/Al2O3 mixed catalyst for condensation-hydrogenation reaction. The Ni/MgO and Ni/Al2O3 with 20% Ni loading were prepared by wet impregnation methods using Ni(NO3)2.6H2O salt, calcined and reduced at 500°C. The catalyst performance was tested for one-step condensation-hydrogenation reaction using autoclave oil batch reactor. The reaction was conducted by reacting furfural and acetone in 1:1 ratio using water as solvent. Condensation reaction was performed at 100°C for 8 hours, followed by hydrogenation at 120°C during 7 hours. Analysis by gas chromatography showed that C=C double bond of furfurylidene acetone were successfully hydrogenated. Using Ni/MgO catalyst at 120°C, the products were identified as 1,5-bis-(2-furanyl)-1,4-penta-1-ene-3-one (2.68%) and 1,5-bis-(2-furanyl)-1,4-pentan-3-one (trace amount). On the other hand, reaction using mixed catalyst, MgO-Ni/Al2O3 showed better activity over bifunctional Ni/MgO at the same reaction temperature. The products were identified as 4-(2-furanyl)-3-butan-2-one (27.30%); 1,5-bis-(2-furanyl)-1,4-penta-1-ene-3-one (3.82%) and 1,5-bis-(2-furanyl)-1,4-pentan-3-one (1.11%). The impregnation of Ni on MgO decrease the physical properties of catalyst, confirmed by surface area analysis (SAA).

UV light-mediated decarboxylative cross-Coupling reaction of aryl acetic acids

A photochemical decarboxylative cross-coupling reaction of aryl acetic acids with 1,4-dicyanobenzene (1,4-DCB) was developed. Under UV light irradiation, the inexpensive aryl acetic acids coupled with 1,4-DCB, isocyanates and alkene derivatives through decarboxylation which led to the corresponding diarylmethanes, amides and alkene derivatives were obtained in moderate to good yields under mild conditions.

Synthesis of Functionalized Cyclopentene Derivatives through Gold-Catalyzed Reaction of Stabilized Vinyldiazo Compounds and Styrenes

The reaction of alkenyldiazo compounds with styrene derivatives in the presence of [Au(IPr)(MeCN)][SbF6] provided cyclopentene derivatives resulting from a formal [3+2] cycloaddition reaction as major products. This reaction outcome stands in marked contrast to that previously observed for other olefinic derivatives. From a mechanistic point of view, this process would involve the initial generation of a highly electrophilic alkenylgold carbene intermediate, which would be subsequently involved in a stepwise carbocationic process.

Monodentate phosphorus-coordinated palladium(II) complexes as new catalyst for Mizoroki-Heck reaction of aryl halides with electron-deficient olefins

Four novel palladium(II) complexes coordinated by phosphorus atoms from both 3,5-disubstituted-1H-1,2,4-diazaphospholes in monodentate fashion were developed as efficient catalyst for the Mizoroki-Heck reaction of aryl halides with electron-deficient olefins. The coupling reaction of aryl halide bearig different functional groups with olefin derivatives took place and the corresponding products were isolated in good to excellent yields under optimal conditions. The procedure exhibits good functional group tolerance and wide substrate scope. This Mizoroki-Heck reaction was further achieved using Pd(OAc)2 and 3,5-di-isopropyl-1H-1,2,4-diazaphospholes as combined catalyst, which provide the convenient and alternative method in organic synthesis

Isolation, characterization and antifungal activity of very long chain alkane derivatives from Cinnamomum obtusifolium, Elaeocarpus lanceifolius and Baccaurea sapida

The aim of this study was to isolate and characterize bioactive secondary metabolites from the flora of the Indo-Burma biodiversity belt for controlling leaf blight disease of Solanum khasianum Clarke (Solanaceae) caused by Alternaria tenuissima and Alternaria alternata during commercial cultivation, the berries of which contains 1.80–3.45% solasodine, a major raw material for steroid drug industries. Three new and two white powdered compounds were extracted from Cinnamomum obtusifolium (Roxb.) Nees (Lauraceae), Elaeocarpus lanceifolius (Roxb.) (Elaeocarpaceae) and Baccaurea sapida (Roxb.) Mull. Arg. (Euphorbiaceae). New compounds were characterized as Triacontanoic acid (1), octatriacontan-1-ol (2) and dotriacontane (3) isolated from C. obtusfolium and E. lanceofolius by 1H, 13C NMR and mass spectroscopy respectively. Other two known compounds were palmitic acid (4) and oleic acid (5) and from B. sapida. Complete inhibition of pathogenic fungi A.tenuissima and A. alternata were observed for compound 2 and 3. Further, in-silico molecular binding analysis of these compounds towards endopolygalacturonase, β-isopropyl dehydrogenase, plasma membrane ATPase, calmodulin, ACR-toxin biosynthesis hydroxylase and synthatase peptide (transcription regulator of Amt-gene) of A. tenuissima and A.alternata revealed that they are effective in inhibiting multiple targets. The antifungal potential of three new isolated compounds from C. obtusifolium and E. lanceifolius is reported for the first time. The results indicate the possible use of triacontanoic acid, octatriacontan-1-ol and dotriacontane as potential antifungal agents.

Modeling Boiling Points of Alkane Derivatives

Modeling Boiling Points of Alkane Derivatives

Alkoxy and Enediyne Derivatives Containing 1,4-Benzoquinone Subunits-Synthesis and Antitumor Activity.

The compounds produced by a living organism are most commonly as medicinal agents and starting materials for the preparation of new semi-synthetic derivatives. One of the largest groups of natural compounds consists of products containing a 1,4-benzoquinone subunit. This fragment occurs in three enediyne antibiotics, dynemicin A, deoxydynemicin A, and uncilamicin, which exhibit high biological activity. A series of alkoxy derivatives containing 1,4-naphthoquinone, 5,8-quinolinedione, and 2-methyl-5,8-quinolinedione moieties was synthesized. Moreover, the 1,4-benzoquinone subunit was contacted with an enediyne fragment. All obtained compounds were characterized by spectroscopy and spectrometry methods. The resulting alkane, alkene, alkyne and enediyne derivatives were tested as antitumor agents. They showed high cytotoxic activity depending on the type of 1,4-benzoquinone subunit and the employed tumor cell lines. The synthesized derivatives fulfill the Lipinski Rule of Five and have low permeability through the blood–brain barrier.