Allyl Chloride Research Articles

Catalytic asymmetric synthesis of carbocyclic C-nucleosides

Access to carbocyclic C-nucleosides (CC-Ns) is currently restricted. The few methods available to make CC-Ns suffer from long syntheses and poor modularity, hindering the examination of potentially important chemical space. Here we report an approach to CC-Ns which uses an asymmetric Suzuki-Miyaura type reaction as the key C-C bond forming step. After coupling the densely functionalized racemic bicyclic allyl chloride and heterocyclic boronic acids, the trisubstituted cyclopentenyl core is elaborated to RNA analogues via a hydroborylation-homologation-oxidation sequence. We demonstrate that the approach can be used to produce a variety of enantiomerically enriched CC-Ns, including a carbocyclic derivative of Showdomycin.

Using Compound Specific Isotope Analysis to decipher the 1,2,3-trichloropropane-to-Allyl chloride transformation by groundwater microbial communities

1,2,3-trichloropropane (TCP), a refractory contaminant, can be reductive dehalogenated to allyl chloride (AC) by microorganisms, which has been shown a potential in situ bioremediation (ISB) strategy for TCP remediation in groundwater. In practice, however, it is hard to monitor the bioreduction extent because the TCP concentrations may also be decreased by non-biodegradation processes. Compound specific isotope analysis (CSIA) can be promising in determining the extent of degradation by quantifying the isotope enrichment factors (ε) of relevant degradation mechanisms. To date, no CSIA study has been reported on TCP degradation. In this study, a novel TCP-to-AC transformation enrichment culture (dominated by Azotobacter, Parabacteroides, Fusibacter, Hydrogenophaga, Trichococcus Desulfovibrio, etc) in the absence of the already identified TCP anaerobic reductive dechlorinating microorganisms (e.g., Dehalogenimonas) was derived from a chlorinated hydrocarbon-contaminated aquifer. A TCP degradation experiment was carried out by adding yeast extract to produce hydrogen as an electron donor. The TCP-to-AC transformation was found to conform to zero-order conversion kinetics with the rate constant 11 ± 0.34 μmol L−1 d−1 during the main biodegradation stage. The bulk carbon isotope enrichment factor (εbulk) of the TCP-to-AC transformation was firstly evaluated as −5.2 ± 0.1‰. This study for the first time characterized the carbon isotope fractionations during TCP biodegradation using a novel enrichment culture, which would provide a promising tool for the incorporation of ISB for TCP removal in the future.

Scale-Up of a Rh-Catalyzed Asymmetric sp3-sp2 Suzuki-Miyaura-Type Reaction.

Csp2-Csp2 Suzuki-Miyaura couplings (SMCs) are ubiquitous in the synthesis of small molecules, but analogous Csp2-Csp3 bond-forming SMCs are rare, especially asymmetric variants. Recently, we developed a series of Rh-catalyzed couplings between racemic sp3-hybridized allyl chlorides and heteroaryl boronic acids. Here, we demonstrate that these catalytic asymmetric reactions can be scaled-up to give over 100 g of a product. The reaction we chose to test couples a heteroaromatic boronic acid derivative and a racemic bicyclic electrophile to give a product with three contiguous stereogenic centers. The SMC product was obtained as a single diastereomer in 90% yield and 98% ee. Kinetic analysis of the reaction reveals two exothermic steps in the reaction setup and revealed the means by which to prevent the generation of heat spikes detrimental to the stability of the catalyst.

Thiophene Ring-Opening Reactions V. Expedient Synthesis of 1,3,4- Thiadiazoline-Sulfanyl[1,3]thiazin-4-one Hybrids

Abstract: The preparation of 6-chloro-5-nitrothieno[3,2-e][1,3]thiazin-4-one incorporating 2-(Nmorpholinyl) moiety is achieved via a conventional route. Interaction of the latter substrate with a set of N'-(aryl) benzothiohydrazides 1a-f, in the presence of triethylamine, led to a thiophene ring-opening process with the consequent generation of the respective thiolate salts 8a-f. Alkylation of the latter, using methyl iodide or allyl chloride, generated the respective novel 1,3,4-thiadiazoline–6-sulfanyl-1,3- thiazin-4-one hybrids, the structures of which were verified by HRMS and NMR spectral data. †Dedicated to the memory of our friend and advisor Professor Dr. Wolfgang Voelter.

Metagenomic characterization of a novel enrichment culture responsible for dehalogenation of 1,2,3-trichloropropane to allyl chloride

Degradation of 1,2,3-trichloropropane (TCP) to allyl chloride (AC) by Dehalogenimonas (Dhg), the only reported TCP anaerobic reductive dechlorinating microorganism so far, has been demonstrated to be effective for in-situ bioremediation (ISB) of groundwater. This process is found viable when augmented with the fermentable organic substrate, yet its environmental implication is not yet clear and limited due to the complex environmental conditions and indigenous microbial communities. In this study, using yeast extract as biostimulant, an enrichment culture capable of dechlorinating TCP derived from groundwater well sludge at a chlorinated aliphatic hydrocarbon (CAH)-contaminated site was incubated. Geochemical methods, 16 S rRNA gene and shotgun metagenomic sequencing were used to systematically monitor the TCP biodegradation kinetics and unravel the functional microbial communities that play pivotal roles in this process. The decrease of TCP, along with the increase of AC (the product of TCP degradation) and δ13C-TCP values indicated active biodegradation of TCP. The 16S rRNA phylogenetic tree showed the absence of Dhg, suggesting a putative novel culture for dechlorinating TCP. Several potential anaerobic reductive functional genes and dominant microorganisms were identified and mutualistic interactions were found. Hydrogenase (H2ase) genes, responsible for producing the hydrogen, were harbored by Desulfovibrio. Cobalamin synthase (CobS) genes, responsible for synthesizing the cobalamin, an important co-factor for dehalogenation, were harbored by Desulfovibrio, Gracilibacter, Thermococcus. By obtaining the electron donor (hydrogen) and essential cofactors (cobalamin), the reductive dehalogenase (Rdh) gene were harbored by Parabacteroides, Caldisalinibacter, and Desulfovibrio. Based on these findings, Desulfovibrio was deduced to be the most promising genus for TCP degradation. The identified microbial community could collaboratively play critical roles in TCP degradation, and therefore, a new method is expected to be developed.

Ligand-Enabled Copper-Catalyzed Regio- and Stereoselective Allylboration of 1-Trifluoromethylalkenes.

A copper-catalyzed regio- and stereoselective allylboration of 1-trifluoromethylalkenes with bis(pinacolato)diboron (pinB-Bpin) and allylic chlorides has been developed to form functionalized trifluoromethylated products with high diastereoselectivity. The key to success is the judicious choice of Cs2CO3 base and t-Bu-modified dppe-type ligand, which enables the otherwise challenging high catalyst turnover and suppression of the competing defluorination side reaction from an alkylcopper intermediate. The product derivatization of the resulting Bpin moiety can deliver diverse CF3-containing molecules with high stereochemical fidelity.

Direct C-H Allylation of Unactivated Alkanes by Cooperative W/Cu Photocatalysis.

Here we report a photocatalytic methodology that enables the direct allylation of strong aliphatic C–H bonds with simple allylic chlorides. The method relies on a cooperative interaction of two metal catalysts in which the decatungstate anion acts as a hydrogen-atom abstractor generating a nucleophilic carbon-centered radical that engages in an SH2′ reaction with an activated allylic π-olefin–copper complex. Because of this dual catalysis, the protocol allows for the functionalization of a range of chemical feedstocks and natural products under mild conditions in short reaction times.

In situ generated micro-catalytic system for the epoxidation of allyl chloride with hydrogen peroxide

The epoxidation of allyl chloride and H2O2 catalyzed by heterogeneous catalyst suffers from inadequate mixing between organic phase, aqueous phase and solid catalyst. This work describes a novel micro-catalytic system for the intensification of this multiphase reaction process. Aqueous phase is capsulated with the loaded phosphotungsten heteropoly acid catalyst to produce microdroplets in situ, the oil-water interface consisting of the catalyst particles facilitates the epoxidation reaction. The regulation of microdroplet size can be achieved by changing the hydrophobicity of the catalyst surface, with a suitable hydrophobicity reducing the diameter of microdroplets and exhibiting optimal catalytic activity. The ECH conversion and selectivity in the micro-catalytic system can be reached as high as 98.02 % and 99 %, respectively. The structure and stability of the catalyst are illustrated by SEM, XPS, FT-IR and TGA. Furthermore, inexpensive commercial polystyrene was used as catalyst carriers, and the synthesis process of the catalyst is simple, which enables the large-scale synthesis of the catalyst. This strategy is a promising approach to designing catalysts for oil-water multiphase reactions.

SYNTHESIS OF NEW MOLECULARLY IMPRINTED SOLID -PHASE UESD STYRENE AND ALLYL CHLORIDE BASE FUNCTIONAL MONOMER FOR DETERMINATION OF COCAINE BY GC-MASS AND ITS CLINICAL APPLICATIONS

This study was aimed to synthesize a new molecularly imprinted polymer using a functional monomer of styrene(STY) and allyl chloride(ALC) and N, N-methylene bis-acrylamide (MBAA) as a cross-linker for the selective extraction of cocaine from urine samples. Cocaine is used as a template to create a monolithic solid-phase micro extraction (SPME) fiber. All of these analytical procedures were utilized to extract, preconcentrate, and selectively determine Cocaine and its derivatives (SPME) with gas chromatography and mass spectrometry (GC/MS). Samples taken from a suspected cocaine addict who was given to the medico-legal directorate as a donation (Baghdad, Iraq). The analytes were monitored using UV-Vis , (GC MS), FTIR and Scanning electron microscopy (SEM). The RSD percent for two patients' repeated studies for three measurements range from (1.587-4.545) percent cocaine 20-100 ppm .

Effect of interfacial activity of quaternary ammonium cation on kinetics of epoxidation of allyl chloride with hydrogen peroxide

A series of quaternary ammonium phosphotungstic heteropoly acid catalysts with different carbon chain lengths [(CnH2n+1)2(CH3)2N]3{PO4[W(O)(O2)2]4} (n = 8, 10, 12, 14, 16) were synthesized for the epoxidation of allyl chloride with H2O2. The hydrophilic and hydrophobic structure of the catalysts were regulated to optimize the interfacial activity by changing the carbon chain lengths of the quaternary ammonium cations. The reaction system using catalyst [(C10H21)2(CH3)2N]3{PO4[W(O)(O2)2]4} showed the lowest interfacial tension between oil and water, the smallest particle size of emulsion droplets and the largest interfacial area, which resulted in the highest catalytic performance. The reaction kinetics and interface properties studies, including the activation energy, interfacial tension, and microscopic imaging of droplets, were conducted to provide strong proof. The epoxidation reaction rates were significantly associated with the surface activity of different carbon chain length catalysts and their effects on the allyl chloride-H2O2 interfacial properties.

Palladium‐Catalyzed Carbonylation of Allylic Chlorides to β,γ‐Unsaturated Esters/Amides under Mild Conditions

AbstractImproved procedures for carbonylative transformations (alkoxy‐ and aminocarbonylation) of cinnamyl chloride to synthesize β,γ‐unsaturated esters/amides have been developed. Studying critical reaction parameters (palladium precursors, solvents and bases) enabled the practical preparation of diverse β,γ‐unsaturated esters/amides under mild conditions (low Pd catalyst loading, phosphine‐free, 2 bar CO, 60 °C). The optimal catalytic system shows excellent chemo‐ and regioselectivity for the activation of the allylic C−Cl bonds.

Asymmetric Synthesis of Nortropanes via Rh-Catalyzed Allylic Arylation.

Tropane derivatives are extensively used in medicine, but catalytic asymmetric methods for their synthesis are underexplored. Here, we report Rh-catalyzed asymmetric Suzuki–Miyaura-type cross-coupling reactions between a racemic N-Boc-nortropane-derived allylic chloride and (hetero)aryl boronic esters. The reaction proceeds via an unexpected kinetic resolution, and the resolved enantiopure allyl chloride can undergo highly enantiospecific reactions with N-, O-, and S-containing nucleophiles. The method was applied in a highly stereoselective formal synthesis of YZJ-1139(1), a potential insomnia treatment that recently completed Phase II clinical trials. Our report represents an asymmetric catalytic method for the synthesis of YZJ-1139(1) and related compounds.

Cycloaddition of allylic chlorides, aryl alkynes, and carbon dioxide using nanoclusters of polyoxomolybdate buckyball supported by ionic liquid on dendritic fibrous nanosilica

Due to the uncontrolled emissions of CO2 created by industrial procedures that lead to acidification of the oceans and universal warming, various methods have been utilized for direct absorption of CO2 from waste water sources. The generation of green nano catalyst with chemical adjustments to be converted to value-added products can be considered alluring. Therefore, we synthesized Polyoxomolybdate [Mo132] nanoball with different alkyl groups loaded on dendritic fibrous nanosilica by ionic liquid (DFNS/IL/Mo132) using an easy synthetic route. Owing to the DFNS/IL/Mo132 morphology, a suitable external level for CO2 uptake was generated at all Mo132 sites. Results revealed that DFNS/IL/Mo132 positively influenced the preparation efficiency of 3a,4-dihydronaphtho[2,3-c]furan-1(3H)-one through a three-element binding reaction of alkynes, allylic chlorides, and carbon dioxide. This approach is beneficial in terms of profitable efficacy and forbearance of functional groups.

Flexibility of Epichlorohydrin Production—Increasing Profitability by Demand Response for Electricity and Balancing Market

The increasing share of variable renewable energies in the power grid is an incentive to explore demand response strategies. Chlor-alkali processes are high potential candidates, according to previous publications. Within Germany’s chemical industry, chlorine production accounts for approximately 20% of electricity use and could play a significant role in power grid stabilisation on the consumer end. This study focuses on the feasibility of load flexibilisation in epichlorohydrin plants, with the second biggest estimated demand response potential for chlorine-based products in Germany. A plant model with allyl chloride storage was created based on real data and literature values. Results from this model, spot market and balancing power prices, and future electricity market scenarios were used in a mixed-integer linear optimisation. We find that benefits from demand response can be generated as soon as additional power and storage volume is provided. The composition of provided types of balancing power bids follows the price trend on the market. Additionally, the computation time could be lowered significantly by running the scenarios in parallel. The results encourage a practical validation of the flexibility of epichlorohydrin production.

Site-selective reactions mediated by molecular containers.

In this review, we summarize various site-selective reactions mediated by molecular containers. The emphasis is on those reactions that give different product distributions on the potential reactive sites inside the containers than they do outside, free in solution. Specific cases include site-selective cycloaddition and addition of arenes, reduction of epoxides, α,β-unsaturated aldehydes, azides, halides and alkenes, oxidation of remote C–H bonds and alkenes, and substitution reactions involving ring-opening cyclization of epoxides, nucleophilic substitution of allylic chlorides, and hydrolysis reactions. The product selectivity is interpreted as the consequence of the space shape and environment inside the container. The containers include supramolecular structures self-assembled through metal/ligand interactions or hydrogen bonding and open-ended covalent structures such as cyclodextrins and cavitands. Challenges and prospects for the future are also provided.

Dispersion, olfactory effect, and health risks of VOCs and odors in a rural domestic waste transfer station

The impact of odorous gases emitted from refuse transfer stations has always been a concern raised by the surrounding residents. The emitted volatile organic compounds (VOCs) and odors were investigated in a rural solid waste transfer station (RSWTS) located in Southwest China. A total of 70 VOCs were identified and quantified. The total VOCs (TVOCs) concentrations varied from 848.38 to 31193.24 μg/m3. Inorganic odor and greenhouse gases concentrations ranged from 39.11 to 470.14 μg/m3 and 1.03–525.42 μg/m3, respectively. Oxygenated compounds contributed the most (58.25%) to the VOCs. Among the oxygenated compounds, ketones, esters, and ethers were the dominant categories, accounting for 67.5%, 12.70%, and 11.85%, respectively. The key odorants included propionaldehyde, hexanaldehyde, propionic acid, acetaldehyde, and disopropyl ether. N-nitrosodiethylamine, acrylonitrile, and 1,3-Butadiene were the three main carcinogens that pose considerable risk to human health. Allyl chloride was the most non-carcinogenic pathogen among the VOCs detected in RSWTS. With diffusion in the downwind direction, the concentration of VOCs decreased gradually, and their risks weakened accordingly. At the sampling site of RSWTS-10, located 100 m away from RSWTS, acrylonitrile and 1,3-Butadiene still presented an unacceptable carcinogenic risk to human health. This study provides new data for assessing the emission characteristics, olfactory effects, and health risks of trace VOCs, especially those released from RSWTS.

In Situ Generated Micro-Catalytic System for the Epoxidation of Allyl Chloride with Hydrogen Peroxide

In Situ Generated Micro-Catalytic System for the Epoxidation of Allyl Chloride with Hydrogen Peroxide

Impact of composition and structural parameters on the catalytic activity of MFI type titanosilicalites.

Titanosilicalite of the MFI type was obtained via a hydrothermal method. Its initial and annealed at 75 °C (TS-1P(75)) and 500 °C (TS-1P(500)) forms were studied by X-ray powder diffraction (PXRD), X-ray absorption spectroscopy (XAS-method), Fourier-transform infrared (FT-IR) spectroscopy, differential scanning calorimetry (DSC), temperature-programmed ammonia desorption (TPD NH3), and pyridine adsorption (Py). The full-profile Rietveld method allowed us to observe the presence of the organic template tetrapropylammonium hydroxide (TPAOH) in the framework voids, as well as to determine the silicate module (Si/Ti = 73.5) and the distribution of Ti4+ ions over the MFI-type structure sites (Ti atoms replace Si ones in two positions: T1 and T6). The coordination numbers of titanium (CNTi = 4.6 for TS-1P and TS-1P(75), CNTi = 3.8 for TS-1P(500)) were established by the XAS-method. The catalytic activity of titanosilicalites was found in the reactions of nitrous oxide decomposition (the maximal decomposition rate is demonstrated for the TS-1P(75) sample), allyl chloride epoxidation to epichlorohydrin (the best combination of all indicators was exhibited for the TS-1P sample) and propane conversion (maximum propane conversion, and butadiene and propylene selectivity were observed in both TS-1P(75) and TS-1P(500) samples). Mechanisms for the catalytic processes are proposed. The relationship between the catalytic properties and the composition (Si/Ti), Ti4+ ion distribution over the MFI-type structure sites, the local environment of titanium ions, and the number of acid sites in the titanosilicalites are discussed.

Effect of Interfacial Activity of Quaternary Ammonium Cation on Kinetics of Epoxidation of Allyl Chloride with Hydrogen Peroxide

Effect of Interfacial Activity of Quaternary Ammonium Cation on Kinetics of Epoxidation of Allyl Chloride with Hydrogen Peroxide

In Situ Generated Micro-Catalytic System for the Epoxidation of Allyl Chloride with Hydrogen Peroxide

In Situ Generated Micro-Catalytic System for the Epoxidation of Allyl Chloride with Hydrogen Peroxide