Olefinic Bond Research Articles

Selective Construction of Borromean Rings andTweezer‐LikeMolecular Assembly Featuring Cp*Rh/Ir Clips forNear‐InfraredPhotothermal Conversion†

Comprehensive SummaryMaking full use of coordination‐driven self‐assembly strategy, we herein described the selective synthesis of a molecular Borromean rings and two cases of “U”‐shaped tweezer‐like molecular assemblies in high yield by using bipyridyl ligands based on biphenyl unit and half‐sandwich binuclear rhodium(III)/iridium(III) building blocks. The selective synthesis was realized by adjusting the length of dipyridyl arms. The utilization of curved U‐shaped bipyridyl ligandL1led to tweezer‐like molecular assemblies. Subsequently, olefinic bonds were introduced to elongate dipyridyl arms obtaining ligandL2. The ligandL2has two stable conformations, U‐shape and Z‐shape, which facilitated the formation of different topologies including the tetranuclear macrocycle and Borromean rings with different building blocks in this work. These structures in solid and solution all have been further confirmed by single‐crystal X‐ray diffraction, NMR analysis, and mass spectrometry. In addition, as an important driving force, π‐π stacking interactions not only played a significant role in the stability of structures but also further triggered photothermal conversion in solution. The experimental results demonstrated that compounds1aand2had good NIR photothermal conversion efficiency (11.83% and 17.76%), and further analysis found the photothermal conversion efficiency had a gradual increase in the trend with the π‐π stacking interactions increasing. This research expands the application of topological structures in materials science and provides a new idea for the synthesis of novel photothermal conversion materials.

Mechanistic Elucidation of a Radical‐Promoted Hydrogenation Relevant to Borrowing Hydrogen Catalysis

AbstractIn the borrowing hydrogen catalysis, hydrogenation of an in situ generated imine or olefinic bond is a crucial step. There is a growing body of literature in olefinic hydrogenation promoted by metal hydride of Earth‐abundant metals, where radical mechanism is followed. This report presents a thorough study of the mechanistic details of a nickel catalyzed α‐alkylation of ketones with secondary alcohols and showcases that the olefinic hydrogenation of an enone happens, completely bypassing the involvement of a metal hydride. This pathway is radical promoted, where a single electron reduction of the substrate olefin and a subsequent hydrogen atom transfer step are most critical. A series of control reactions, detection of critical reaction intermediates, and radical probe experiments provide compelling proofs for such radical‐promoted olefinic hydrogenation. The experimental clues, further aided by DFT calculations altogether suggest the precise one‐electron chemistry where the involvement of metal‐hydride is not required. Notably, the redox non‐innocence of the azophenolate backbone, as well as imposed noninnocence of the substrate olefin, when bound to the catalyst molecule makes such mechanism feasible.

Regioselective Claisen-Schmidt Adduct of 2-Undecanone from Houttuynia cordata Thunb as Insecticide/Repellent against Solenopsis invicta and Repositioning Plant Fungicides against Colletotrichum fragariae.

The U.S. Department of Agriculture (USDA) has established research programs to fight the phytopathogen Colletotrichum fragariae and the invasive red imported fire ant, Solenopsis invicta. C. fragariae is known to cause anthracnose disease in fruits and vegetables, while S. invicta is known for its aggressive behavior and painful stings and for being the cause of significant damage to crops, as well as harm to humans and animals. Many plants have been studied for potential activity against C. fragariae and S. invicta. Among the studied plants, Houttuynia cordata Thunb has been shown to contain 2-undecanone, which h is known for its antifungal activity against Colletotrichum gloesporioides. Based on the mean amount of sand removed, 2-undecanone showed significant repellency at 62.5 µg/g, similar to DEET (N,N-diethyl-meta-toluamide), against S. invicta. The 2-Undecanone with an LC50 of 44.59 µg/g showed toxicity against S. invicta workers. However, neither H. cordata extract nor 2-undecanone had shown activity against C. fragariae despite their known activity against C. gloesporioides, which in turn motivates us in repositioning 2-undecanone as a selected candidate for a Claisen-Schmidt condensation that enables access to several analogs (2a-f). Among the prepared analogs, (E)-1-(3-methylbenzo[b]thiophen-2-yl)dodec-1-en-3-one (2b) and (E)-1-(5-bromothiophen-2-yl)dodec-1-en-3-one (2f) showed promising activity against C. fragariae, revealing a distinctive structural activity relationship (SAR). The generated analogs revealed a clear regioselectivity pattern through forming the C=C alkene bond at position C-1. These data open the window for further lead optimization and product development in the context of managing C. fragariae and S. invicta.

Proximity-Enabled Photochemical C-H Functionalization using a Covalent Organic Framework-Confined Fe2IV-μ-oxo Species in Water.

Water has been recognized as an excellent solvent for maneuvering both the catalytic activity and selectivity, especially in the case of heterogeneous catalysis. However, maintaining the active catalytic species in their higher oxidation states (IV/V) while retaining the catalytic activity and recyclability in water is an enormous challenge. Herein, we have developed a solution to this problem using covalent organic frameworks (COFs) to immobilize the (Et4N)2[FeIII(Cl)bTAML] molecules, taking advantage of the COF's morphology and surface charge. By using the visible light and [CoIII(NH3)5Cl]Cl2 as a sacrificial electron acceptor within the COF, we have successfully generated and stabilized the [(bTAML)FeIV-O-FeIV(bTAML)]- species in water. The COF backbone simultaneously acts as a porous host and a photosensitizer. This is the first time that the photochemically generated Fe2IV-μ-oxo radical cation species has demonstrated high catalytic activity with moderate to high yield for the selective oxidation of the unactivated C-H bonds, even in water. To enhance the catalytic activity and achieve good recyclability, we have developed a TpDPP COF film by transforming the TpDPP COF nanospheres. We have achieved the regio- and stereoselective functionalization of unactivated C-H bonds of alkanes and alkenes (3°:2° = 102:1 for adamantane with the COF film), which is improbable in homogeneous conditions. The film exhibits C-H bond oxidation with higher catalytic yield (32-98%) and a higher degree of selectivity (cis/trans = 74:1; 3°:2° = 100:1 for cis-decalin).

Construction of Photoreactive Chiral Metal-Organic Frameworks and Their [2 + 2] Photocycloaddition Reactions.

Chiral metal-organic frameworks (CMOFs) and solid-state [2 + 2] photocyclization have been explored as independent areas in crystal engineering. We herein report the photoreactive CMOFs that undergo a [2 + 2] photocycloaddition reaction for the first time. Through the incorporation of a dipyridyl olefin ligand, 1,4-bis[2-(4-pyridyl)ethenyl]benzene, and d-camphoric acid or l-camphoric acid, we constructed a pair of homochiral Zn(II) CMOFs (d-1 or l-1) with a two-dimensional sql topology via a two-step procedure to avoid racemization. Both d-1 and l-1 were photoinert due to the large olefin bond separation. The removal of the solvent molecules between layers enabled them (d-1a and l-1a) to undergo [2 + 2] cycloaddition reactions; d-1a is more reactive (70%) than l-1a (20%) probably due to proper desolvation-induced rearrangement. The photoluminescence properties are also discussed. This work presents a new perspective on photoreactive homochiral network materials with diverse topologies and applications.

Liquid chromatography–high-resolution tandem mass spectrometry of anatoxins, including new conjugates and reduction products

Anatoxins (ATXs) are a potent class of cyanobacterial neurotoxins for which only a handful of structural analogues have been well characterized. Here, we report the development of an LC–HRMS/MS method for the comprehensive detection of ATXs. Application of this method to samples of benthic cyanobacterial mats and laboratory cultures showed detection of several new ATXs. Many of these result from nucleophilic addition to the olefinic bond of the α,β-unsaturated ketone functional group of anatoxin-a (ATX) and homoanatoxin-a (hATX), analogous to the conjugation chemistry of microcystins, which contain similar α,β-unsaturated amide functionality. Conjugates with glutathione, γ-glutamylcysteine, methanethiol, ammonia, methanol and water were detected, as well as putative C-10 alcohol derivatives. Structural confirmation was obtained by simple and selective analytical-scale semisynthetic reactions starting from available ATX standards. Methanol, water and ammonia conjugates were found to result primarily from sample preparation. Reduction products were found to result from enzymatic reactions occurring primarily after cell lysis in laboratory cultures of Kamptonema formosum and Cuspidothrix issatschenkoi. The relative contributions of the identified analogues to the anatoxin profiles in a set of 22 benthic-cyanobacterial-mat field samples were estimated, showing conjugates to account for up to 15% of total ATX peak area and 10-hydroxyanatoxins up to 38%. The developed methodology, new analogues and insight into the chemical and enzymatic reactivity of ATXs will enable a more comprehensive study of the class than possible previously.

Computational Quantum Chemical Study, Insilco Molecular Docking and ADMET Study of (3E,5E)-3,5-Bis((1H-Indol-3-yl)Methylene)-1-Benzylpiperidin-4-One Derivatives

The title compound (3E,5E)-3,5-bis((1H-indol-3-yl)methylene)-1-benzylpiperidin-4-one (BIMBP) was deliberated optimal structure, data were calculated using the density functional theory (DFT) B3LYP method on 6-31 G (d, p) basis set and the experimental bond length and bond angles are compared with experimental data. The six-member piperidin-4-one ring adopts a chair conformation with the benzyl group occupying an equatorial position and the olefinic double bonds possessing an E configuration by DFT method. The stability and charge delocalization of the molecule were also studied by natural bond orbital (NBO) analysis. The calculated energies for the Highest Occupied Molecular Orbital (HOMO) and the Lowest Unoccupied Molecular Orbital (LUMO) showed the stability and reactivity of the title compound. The molecular electrostatic potential (MEP) picture was drawn using the same level of theory to visualize the chemical reactivity and charge distribution on the molecule. The reported BIMBP molecule used as a potential NLO material since it has high μβ0 value. Molecular docking study performed for the synthesized compound revealed an efficient interaction with the antibacterial protease and resulted in good activities. Virtual ADMET studies were carried out as well and a relationship between biological, electronic, and physicochemical qualifications of the target compound was determined. Toxicity prediction by computational technique for the title compound was also carried out.

A DFT Mechanistic Study of the Regio-, Chemo-, and Stereo- Selectivities of the (3 + 2) Cycloaddition of Diarylnitrone Derivatives with 1-(4-Nitrophenyl)-5H-Pyrrolin-2-One

Heterocyclic compounds are vital in rational drug design by providing convenient means for the optimization of drugs or drug candidates. Isoxazolidine (a heterocyclic compound) derived from the (3 + 2) cycloaddition reaction is reported to possess anticancer, antiviral, antibacterial, and anti-inflammatory properties. The mechanistic study of the chemo-, regio-, and stereo-selectivities of the (3 + 2) cycloaddition reaction (32CA) of diarylnitrones (A1) to 1-(4-nitrophenyl)-5H-pyrrolin-2-one (A2) has been conducted using the density functional theory (DFT) method at the M06/6-311G (d,p) computational level. The 32CA reaction of A1 and A2 proceeds through a chemo-selective addition of A1 across the C=C olefinic bond of A2 to furnish both kinetically and thermodynamically favored reaction routes. The effect of substitution on the 32CA reaction has been studied using a representative set of electron-acceptor and electron-releasing groups on both A1 and A2. The chemo-, regio-, and stereo-selectivities observed in the 32CA reaction remained unchanged irrespective of the substituents used on both reactants, but a change in kinetics and thermodynamics was observed based on the substituents. In the 32CA reaction of A1 and A2, the “exo” cycloadduct formation was favored over the “endo” cycloadducts in all instances.

Fluoroalkyl Iodides in Fluoroalkylative Difunctionalization of C−C Multiple Bonds

AbstractFluorinated alkyl iodides serve as a convenient and inexpensive source of fluoroalkyl radicals that can readily undergo addition to the C−C unsaturated bonds of alkynes and alkenes which is the foundation for a variety of useful synthetic protocols. Since 2010 this field has witnessed huge progress in several respects. First the portfolio of fluorinated alkyl iodides was extended beyond only simple perfluoroalkyl iodides (CnF2n+1I). In particular, employment of iododifluoro−methyl‐ carbonyls and phosphonates has enabled facile installation of the medicinally relevant difluoromethylene motif. Secondly, from a conceptual point of view, novel strategies for activation of fluoroalkyl iodides towards radical formation have been introduced, relying on the formation of electron donor‐acceptor (EDA) complexes, photoredox catalysis, frustrated Lewis pairs and transition metal catalysis, complementing prior approaches based on heat and UV induced C−I homolysis, radical initiators, and simple electron transfer processes. Based on these strategies a range of novel fluoroalkylative transformations of unsaturated systems have been added to classical iodoperfluoroalkylation. Broadly applicable protocols for simple fluoroalkylation and hydrofluoroalkylation, as well as for more sophisticated, complexity‐building methods of fluoroalkylation‐annulation and tandem multicomponent fluoroalkylations with concomitant installation of another functionality have been recently disclosed. This review summarizes the progress achieved since 2010 in the reactivity of fluoroalkyl iodides towards alkenes and alkynes with emphasis placed on the above‐mentioned advances.

Endosymbiotic bacteria from donkeys milk in the inhibition of human pathogens

Donkey milk is known for its beneficial aspects such as low fat and cholesterol, total protein and casein content, high lactose, whey protein, calcium, selenium and vitamin D3 content. It also has nutraceutical and utilitarian properties that can boost invulnerability, regulate digestion and conveniently change gut microbiota. The current study was focused on the effect of probiotic bacterial metabolites from donkey milk against human bacterial pathogens. The effective isolate VITRAAJ14 was found to be non-hemolytic and was tolerant to acid, NaCl and bile salt. Antibacterial activity by cross streak method showed maximum zone of inhibition. Well diffusion method also exhibited effective inhibition against Escherichia coli (MTCC No. 9721), Staphylococcus aureus (MTCC No. 3160) and Salmonella enterica (MTCC No. 8587) with fractions obtained from chloroform: ethyl acetate. The metabolites capable of inhibiting pathogens were identified as oleyl alcohol by Gas chromatography- mass spectrometry (GCMS). Lead compounds detected in GCMS was studied for its functional group by Fourier transform infrared spectroscopy (FTIR), which revealed the presence of alcoholic stretch, carboxylic acid OH stretch, alkene and amide bond. The isolate VITRAAJ14 was identified to be the closest neighbour of Bacillus species (MH100985) by 16S rRNA gene sequencing. To our knowledge, current study is the first-time report on the presence of Bacillus sp. from donkey milk showing antibacterial activity due to its ability to produce oleyl alcohol. Scanning electron microscopic images revealed the presence of rod-shaped morphology of the effective bacterium VITRAAJ14.

Reductive chemistry of pyrrolic macrocycles: A PCET dichotomy between metal and ligand

Proton-coupled electron transfer (PCET) is central to the reactivity of porphyrins. The coupling of the electron to the proton is central to a porphyrin’s ability to catalyze energy conversion reactions of which the hydrogen evolution reaction (HER) is exemplary. To understand the mechanistic details of the PCET chemistry of porphyrins and related macrocyclic congeners, we have designed hangman constructs that allow a proton, placed in the secondary coordination sphere (off of the hangman backbone), to be coupled to redox transformations at the macrocycle. For metals whose reduction potentials are positive of the porphyrin macrocycle, such as Co and Fe, HER catalysis is confined to PCET transformations of the metal center where the active catalyst for HER is a reduced metal hydride. Alternatively, the reduction potentials of Ni, Zn, and 2H (freebase) porphyrins allow for redox non-innocence of the macrocycle; here the active “hydridic” catalyst is a phlorin, which gives rise to elaborate HER reaction sequences. Beyond HER catalysis, redox non-innocence of Ni, Zn, and 2H porphyrins and related compounds has been informative for providing detailed mechanistic insight into the multi-site PCET hydrogenation of olefinic bonds of the macrocycle. This mini-review unravels the PCET dichotomy between the metal and macrocycle in promoting HER catalysis and novel chemical transformations that give rise to unusual macrocyclic structures.

Theoretical insight into the unexpected initial (3 + 2) cycloaddition reaction of mesitonitrile oxide with 1, 4-diazepine derivatives: A computational study

1,4-Diazepine as an active drug component underlies the potency of most psychotic, anticancer, anticonvulsant, and antibacterial drugs in the market and is, therefore crucial in chemotherapeutic treatment in biomedicine. Proper functionalization of this moiety can afford even more potent drugs. As a result of their therapeutic significance, this study aims at precisely giving a comprehensive computational insight into the unexpected initial reactivity of 1,4-diazepine derivatives and mesitonitrile oxide. The initial reaction between mesitonitrile oxide and 1,4-diazepine derivatives proceeds via a (3 + 2) cycloaddition reaction which leads to the formation of a cycloadduct where the mesitonitrile oxide unexpectedly adds across the imine functionality at the expense of the potential olefinic carbon-carbon double bond. Calculations at the density functional theory (DFT) M06/6-311G (d, p) level of theory indicate that the initial (3 + 2) cycloaddition reaction of mesitonitrile oxide (1,3-dipole) and 1,4-diazepine derivatives (dipolarophile) in all cases proceeds to form the cycloadduct where the 1,3-dipole adds preferentially to the imine functionality at the expense of the potential olefinic carbon-carbon double bond. In light of the parent reaction, the most kinetically favored cycloadductP3A had a rate constant of 5.1 × 106 M−1s−1, which is about 12 manifolds faster than the next competing stereoisomer P1A with a rate constant of 4.1 × 105 M−1s−1 and about 1024 faster than the most favored cycloadduct P3B with a rate constant of 7.2 × 10−19 M−1s−1 in the unfavored pathway (Path B). Irrespective of the electronic and steric nature of the electron-donating (EDG) and electron-withdrawing (EWG) substituents placed on the dipolarophile, the selectivities of the reaction were maintained. Rationalization of the potential energy surface depicts that the 1,3-dipole adds across the dipolarophile via an asynchronous concerted mechanism. Rationalization of the HOMO-LUMO energies of the mesitonitrile oxide (1,3-dipole) and the 1,4-diazepine derivatives (dipolarophile) depict that the EDG-substituted dipolarophile react as nucleophiles, whereas the dipole reacts as an electrophile. Conversely, the HOMO-LUMO interaction between the EWG-substituted dipolarophile indicates that the EWG-substituted dipolarophile react as electrophiles, whereas the dipole reacts as a nucleophile. The electrophilic parr function at various reactive sites of the dipolarophile shows that the 1,3-dipole preferentially adds across the local centers with the largest electrophilic NBO or Mulliken spin densities which is consistent with the energetic trend observed. The reactivity of the 1,4-diazepine derivatives and the mesitonitrile oxide showed poor stereoselectivity.

Synthesis of sugar enones and their use as powerful synthetic precursors of thiodisaccharides

Monosaccharide derivatives having a double bond conjugated to a carbonyl (sugar enones or enuloses) are relevant synthetic tools. They are also suitable starting materials, or versatile intermediates, for the synthesis of a wide variety of natural or synthetic compounds with a broad spectrum of biological and pharmacological activities. The preparation of enones is mainly focused on the search for more efficient and diastereoselective synthetic methodologies. The usefulness of enuloses relies on the diverse reaction possibilities offered by alkene and carbonyl double bonds, which are prone to undergo varied reactions such as halogenation, nitration, epoxidation, reduction, addition, etc. The addition of thiol groups that led to sulfur glycomimetics, such as thiooligosaccharides, is particularly relevant. Therefore, the synthesis of enuloses and the Michael addition of sulfur nucleophiles to give thiosugars or thiodisaccharides are discussed here. Chemical modifications of the conjugate addition products to afford biologically active compounds are also reported.

Radical Cascade Cyclization of Alkene‐Tethered Compounds: Versatile Approach towards Ring‐Fused Polycyclic Structures

AbstractRing‐fused polycyclic structures widely exist in a myriad of natural products and pharmaceutical molecules. Consequently, the construction of such structures from readily available substrates becomes an important researching topic in organic synthesis. Triggered by the addition of radicals to the (activated or unactivated) double bonds in alkenes, the subsequent intramolecular addition/cyclization leads to polycyclic compounds. Following this procedure, a variety of functionalized ring‐fused structures were formed. Great achievements have been witnessed recently. Those works provided efficient, atom economy, and operational simple approaches toward versatile functionalized polycyclic structures from readily available alkene‐based substrates. Here, we summarized the recent achievements on the formation of ring‐fused polycyclic structures via the radical‐triggered cascade reactions of alkenes. Construction of polycyclic structures with no less than 3 fused rings developed during the last decade were included in this Review, corresponding mechanisms were also discussed.

Selective Synthesis and Structural Transformation of a 4-Ravel Containing Four Crossings and Featuring Cp*Rh/Ir Fragments.

Intricately interwoven topologies have been continually synthesized and are ultimately equally versatile and significant at the nanoscale level; however, reports concerning ravel structures, which are highly entwined new topological species, are extremely rare and fraught with tremendous synthesis challenges. To solve the synthesis problem, a tetrapodontic pyridine ligand L1 with two types of olefinic bond units and two Cp*M-based building blocks (E1, M=Rh; E2, M=Ir) featuring large conjugated planes was prepared to perform the self-assembly. Two unprecedented [5+10] icosanuclear molecular 4-ravels containing four crossings were obtained by parallel-displaced π···π interactions in a single-step strategy. Remarkably, reversible structural transformations between 4-ravel and the corresponding metallocage could be realized by concentration changes and solvent- and guest-induced effects. X-ray crystallographic data and NMR spectroscopy provide full confirmation of these phenomena.

Selective Synthesis and Structural Transformation of a 4‐Ravel Containing Four Crossings and Featuring Cp*Rh/Ir Fragments

AbstractIntricately interwoven topologies are continually being synthesized and are ultimately equally versatile and significant at the nanoscale level; however, reports concerning ravel structures, which are highly entwined new topological species, are extremely rare and fraught with tremendous synthesis challenges. To solve the synthesis problem, a tetrapodontic pyridine ligand L1 with two types of olefinic bond units and two Cp*M‐based building blocks (E1, M=Rh; E2, M=Ir) featuring large conjugated planes was prepared to perform the self‐assembly. Two unprecedented [5+10] icosanuclear molecular 4‐ravels containing four crossings were obtained by parallel‐displaced π⋅⋅⋅π interactions in a single‐step strategy. Remarkably, reversible structural transformations between the 4‐ravel and the corresponding metallocage could be realized by concentration changes and solvent‐ and guest‐induced effects. X‐ray crystallographic data and NMR spectroscopy provide full confirmation of these phenomena.

Significant acceleration of E-Z photoisomerization induced by molecular planarity breaking

E-Z photoisomerization constitutes the footstone of photosensitive proteins, molecular photoswitches and sunscreens and is believed to be controlled by photoinduced intramolecular charge transfer. In this work, we have made methylation on isomerizable alkene bond of plant sunscreen sinapate esters to break the coplanarity between phenol ring and CC double bond in ground state. Femtosecond transient absorption spectroscopy combined with time-dependent density functional theory calculations determine that this molecular planarity breaking triggers an immediate excited-state CC double bond twisting and thus accelerates the isomerization by more than one order of magnitude. These results highlight the role of molecular geometry on isomerization dynamics.

Nickel-Catalyzed Remote C(sp3)–N/O Bond Formation of Alkenes with Unactivated Amines and Alcohols

Transition metal-catalyzed remote hydrofunctionalization of alkenes is an efficient method to realize C(sp3)–H functionalization. However, remote hydrofunctionalization of alkenes with unactivated amines and alcohols has not been successfully developed to date. Herein, we report an efficient nickel-catalyzed remote hydroamination and hydroetherification of alkenes with unactivated amines and alcohols, accessing a series of gem-diamine and N,O-acetal derivatives in good to high yields (up to 93%) and exclusive regioselectivities. The mechanistic investigations and DFT computations indicated that the use of 2-iodo-2-methylpropane (tBuI) as both a mild hydride source and radical precursor was essential to afford the remote functionalized products. This research work provides an efficient method to install an amino or alkoxyl group at the C(sp3)–H position that is far from the double bond of alkenes.

Palm Oil Valorization through the Oxidative Cleavage of Unsaturated Fatty Acids with Ru-Carbon Catalysts

Palm oil valorization for the production of azelaic acid, highly demanded for the treatment of skin cancer, was performed through the oxidative cleavage of unsaturated fatty acids. In this reaction, olefinic bonds are broken to yield carboxylic and dicarboxylic acids. To do so, carbon black and carbon micrometric particles were functionalized with polydopamine to form complexes with Ru. These Ru-carbon catalysts were fully characterized before catalytic tests, where triglycerides within palm oil were transformed into fatty acid methyl esters first and then incorporated in our catalytic system formed by H2O/MeCN/AcOEt. After adding NaIO4 and N-methylmorpholine N-oxide (oxidizing agents), our Ru-carbon catalysts reached a complete >99% conversion in 5 h of reaction at room temperature with yields of azelaic acid around 85%. Although Ru species were found in the liquid phase during the reaction, the solid catalysts managed to recover them to keep the same catalytic activity for five recycling tests. Therefore, our Ru-carbon catalysts open a novel route for the production of a high-value-added product with medicinal applications from a cheap feedstock such as palm oil.

Mechanism of chlorotriflamidation of vinylsilanes with <i>N</i>,<i>N</i>-dichlorotriflamide

The mechanism of the reaction of vinylsilanes with N , N -dichlorotriflamide and the effect of a substituent at the silicon atom on the reaction course and on the charge distribution in substrates and their carbon analogues were studied by DFT method. The C=C bond in vinylsilanes and alkenes is polarized in the opposite way. The reaction proceeds in two stages: chlorination of the substrate with the formation of a chloronium ion, and its opening at the Cβ-Cl bond by the N -chlorotriflamide anion. Transition states of two stages were calculated. The reaction products are hydrolyzed to NH-derivatives; their IR spectra and supramolecular structure, including cyclic and linear dimers, calculated in the gas phase and in a polar medium, were studied.