Internal Alkenes Research Articles

Study of sodium electrolytes on phase behavior of the anionic surfactant/alcohol/model oil system and its application for alkaline-surfactant flooding formulation design

In this study, the phase behavior of several anionic surfactants, i.e., one internal olefin sulfonate, the sodium dodecyl sulfate and the dodecyl benzene sulfonate, were conducted to investigate the influence of different sodium electrolytes on the optimal salinity of the anionic surfactant/alcohol/model oil system. The sodium activity at the optimal salinity was calculated by the PHREEQC software, which was found to be equal between different sodium electrolytes. Noticeably, the solubilization parameter of water or oil at the optimal salinity was not influenced by the anions, but largely dependent on the alcohol type, the oil type and the temperature. Furthermore, oleic acid was added into model oil to simulate the acid components in crude oil. The phase behavior results indicated that a larger fraction of oleic acid was active at higher pH with sodium hydroxide (NaOH), however, its solubilization parameter at optimal salinity was lower compared to that using sodium carbonate (Na2CO3). The phase behavior of alkali/crude oil was also performed by mixing different alkalis with a crude oil sample that consisted of high contents of water-soluble active soaps. It is found that the soap generated by NaOH is more lipophilic than that generated by Na2CO3. When sodium activity is used, the optimal salinity of alkali/surfactant/crude oil system can be accurately predicted by the improved mixing rule correlation. The findings of this study would be helpful for us to rapidly select the optimum formulation for alkaline/surfactant flooding process.

Carboxylate-Assisted Palladium-Catalyzed Regio- and Stereoselective Mizoroki-Heck Arylation of β-Cyclohexadienyl Acrylates and Styrenes.

A carboxylate-assisted palladium-catalyzed Mizoroki-Heck arylation of electron-deficient internal alkenes is described herein. This protocol utilized a free carboxylic acid as the directing group for regio- and stereoselective Mizoroki-Heck arylation of β-cyclohexadienyl acrylates and styrenes with various aryl iodides. The synthetic application has been exhibited by decarboxylative aromatization and iodolactonization/hydrolysis of the resulting polyenes providing trisubstituted alkenes and structurally diverse hydroxyl lactones. Additionally, mechanistic studies have been performed to elucidate the reaction outcome of regio- and stereoselectivity.

Iridium-Catalyzed Regioselective Hydroalkynylation of Internal Alkenes Directed by an Oxime.

We report here an iridium-catalyzed hydroalkynylation of allylic alcohols protected by an oxime group. Catalytic alkynylation occurs exclusively at the distal position of the alkene. This method generates γ-alkynyl alcohol oximes directly from internal alkenes and terminal alkynes. The oxime group can be readily removed to afford a free alcohol, thus providing an indirect route for the catalytic hydroalkynylation of allylic alcohols.

12-Tungstophosphate Acids: An Efficient, Green and Recyclable Photocatalyst in Carbon-Carbon Double Bond Isomerization on Linear Alpha Olefins

The accelerated UV visible photocatalytic carbon-carbon double bond isomerization of Linear Alpha Olefins (LAO) with 12-Tungstophosphate Acids (12-TPA) as an efficient, environmentally-friendly and recyclable catalyst was described, which produced the corresponding Linear Internal Olefins (LIO) in general high selectivity and high yields.

Enhanced oil recovery with anionic and zwitterionic surfactants in carbonate rocks: A CT-aided investigation

Surfactant-polymer enhanced oil recovery (EOR) in carbonates is challenging at high salinity/hardness and high temperature conditions due to poor aqueous stability at these conditions. This work finds that a surfactant blend of zwitterionic surfactant (lauryl betaine) and anionic surfactants (carboxylate & internal olefin sulfonate – IOS) that is aqueous stable at 4–6 wt% salinity and 100 °C and has ultralow water/oil interfacial tension (IFT) to allow near-miscible water/oil displacement to enhance oil recovery. The surfactant-polymer aqueous stability is greatly improved after mixing 2 wt% oil to create a homogeneous oil-in-water microemulsion. Flow experiments are conducted at 100 °C in Indiana limestone cores with vugs and microporosity. The zwitterionic-anionic surfactant blend reduces oil saturation to 10% and drains oil in pores ≥200 nm. In comparison, the anionic blend (carboxylate + IOS) reduces oil saturation to 23% and drains oil in pores ≥1 μm. The adsorption of both surfactant blends on carbonate is less than 0.4 mg/g. Particularly, the X-ray computed tomography (CT) images show a negative correlation between pixel-wise oil saturation and porosity during oil displacements by water and by surfactant/polymer. This correlation is likely due to capillary pressure and the mixed wettability of the Indiana limestone. These results provide new surfactant formulations for EOR at extreme conditions and insights for modeling EOR in rocks with porosity heterogeneity and mixed-wettability.

Examination of Milstein Ru-PNN and Rh-Tribi/Tetrabi dual metal catalyst for isomerization-linear-hydroformylation of C4 raffinate and internal olefins

Isomerization-linear-hydroformylation is demanding, however, not an addressed issue, for the production of value-added linear aldehydes by converting cheap and abundant internal alkenes available from bio- & petrochemical industry. In this paper, a dual metal catalysis system combining a Ru-isomerization catalyst and a Rh-linear-hydroformylation catalyst satisfying the “4S” criterions was reported for isomerization-linear-hydroformylation of C4 raffinate (mixed butenes) and internal olefins. The optimized dual metal catalyst system hydroformylated Raffinate II feed to valuable valeraldehyde in 98% linear selectivity (n:i ​= ​49), 80% conversion and high activity of 1069 h−1 TOF whereas 96% linear selectivity (n:i ​= ​24), 71% conversion and 948 h−1 TOF were observed using only the Rh-hydroformylation catalyst. Notably, valeraldehyde are produced in million tons scale annually for making non-toxic plasticizer DPHP. Various 2-olefins were also converted to linear aldehydes in > 98% linear selectivity (n:i ​> ​49), 78%–82% conversion and high activity of 802–851 h−1 TOF.

A relay catalysis strategy for enantioselective nickel-catalyzed migratory hydroarylation forming chiral α-aryl alkylboronates

A relay catalysis strategy for enantioselective nickel-catalyzed migratory hydroarylation forming chiral α-aryl alkylboronates

Ynamide Protonation-Initiated Cis -Selective Polyene Cyclization and Reaction Mechanism

The diastereoselectivity of conventional polyene cyclization reactions is highly dependent on the configuration of the internal alkenes, where E-polyenes provide trans-decalins, while Z-polyenes of...

Practical Synthesis of (Z)-α,β-Unsaturated Nitriles via a One-Pot Sequential Hydroformylation/Knoevenagel Reaction.

Herein, the synthesis of (Z)-α,β-unsaturated nitriles by a sequential hydroformylation/Knoevenagel reaction has been first developed. A variety of crude α-olefins from Fischer-Tropsch synthesis, internal and special olefins, as well as alkynes could be transformed into value-added alkenyl nitriles (39 examples) up to 90% yield. Remarkably, compared with commonly used tedious multistep reactions, the one-pot protocol features cheap and easily available raw materials, excellent chemo-, regio-, and stereoselectivity, very mild reaction conditions, and easy scale-up production.

Directed Nickel-Catalyzed Diastereoselective Reductive Difunctionalization of Alkenyl Amines.

We report herein an intermolecular syn-arylalkylation and alkenylalkylation of alkenyl amines with two different organohalides (iodides and bromides) using Ni(II) catalyst. The cleavable bidentate quinolinamide is utilized after extensive directing group screening to enable olefin difunctionalization with high levels of regio-, chemo-, and diastereocontrol. This general and practical protocol is compatible with α- or β-substituted terminal alkenes and internal alkenes, providing rapid access to branched aliphatic amines bearing two skipped and vicinal stereocenters with high diastereoselectivities that would otherwise be difficult to synthesize.

Increasing Olefin Metathesis Activity of Silica‐Supported Molybdenum Imido Adamantylidene Complexes through E Ligand σ‐Donation

AbstractMolybdenum imido adamantylidene complexes with different substituents on the imido ligand (dipp=2,6‐diisopropylphenyl, ArF5=C6F5, and tBu) having distinct electron donating abilities were investigated for the metathesis of internal and terminal olefins, for both molecular and silica‐supported species using standardized protocols. Here we show that surface immobilization of these compounds results in dramatically increased activity compared to their molecular counterparts. Additionally, we show that electron withdrawing imido groups increase the activity of the compound towards terminal olefins while they simultaneously decrease the ability to metathesize internal olefins. Furthermore, these systems also show high stability when used as initiators in olefin metathesis, although the species that display higher initial activity deactivate faster than those that show more a more moderate reaction rate at first. Our catalytic studies, augmented by DFT calculations, show that all investigated compounds have a remarkably small energy difference between the trigonal bipyramidal (TBP) and square planar (SP) configurations of the metallacyclobutane intermediates, which has previously been linked to high activity.

Molecular Dynamics Study on Performance of Olefin Sulfonate at the Decane–Water Interface: Effect of Molecular Architecture

Surfactant flooding has been widely employed to recover the residual oil in the oilfields. Among the various oil-displacing chemicals, olefin sulfonate isomers have been identified as effective chemical agents by many experiments due to the realization of low interfacial tension (IFT) at the oil–water interface, and tolerance for high salinity and high temperature under reservoir conditions. The molecular architecture (e.g. degree of branching) of the surfactant can significantly affect the oil–water interfacial properties and hence its performance. Herein, molecular dynamics simulations were performed to investigate the adsorption processes of alpha olefin surfactant (AOS with single-tailed structure) and internal olefin surfactant (IOS with twin-tailed structure) at the oil (n-decane) - water interface under oil reservoir condition. The results show that IOS can significantly reduce the IFT at high concentrations, and the formed monolayers at the interface are more stable compared with AOS. The steric hindrance effect by the short chain of IOS can inhibit the aggregation behavior, thus leading to larger interfacial coverage, which are favorable to separation of the water and decane phases. The larger distance between the headgroups of IOS molecules is conducive to formation of hydrogen bonds between the surfactant and water molecules, and hence enhances the interaction between the IOS and water molecules at the inerface. Based on the analysis of order parameter, the middle segment of AOS molecules and the long chain of IOS molecules are mainly contributed to the Van der Waals’ interaction between the surfactant alkyl tails and decane molecules. Meanwhile, the twin-tailed structure of IOS has more favorable effective alkyl tail length (i.e. better miscibility with the oil phase) compared with the single-tailed structure of AOS. Consequently, the twin-tailed structure is superior to the single-tailed structure in terms of interfacial performance, and it is strongly suggested for the design of advanced surfactants in EOR implementation.

Regioselective nickel-catalyzed dicarbofunctionalization of unactivated alkenes enabled by picolinamide auxiliary

Catalytic difunctionalization of alkenes has been a prominent research theme in recent years. Here, we develop a removable bidentate picolinamide-assisted regioselective dicarbofunctionalization of homoallylic amines with organohalides and arylboronic acids. The catalytic system, using cost-effective and air-stable Ni(II) precatalyst, which could be activated by arylboronic acids, provides access to the regioselective diarylation and arylalkylation of unactivated alkenes. This reaction is compatible with α- or β-substituted terminal alkenes and internal alkenes and exhibits excellent functional group and heterocycle tolerance. Preliminary mechanistic studies suggest that the reaction proceeds via a NiI/NiIII catalytic cycle rather than a Ni0/NiII cycle. Notably, the general and practical protocol developed herein represents, to the best of our knowledge, the first example of Ni-catalyzed 3-component 2,1-diarylation and arylalkylation of alkenes with arylboronic acids and organohalides.

Ni-Catalyzed Arylbenzylation of Alkenylarenes: Kinetic Studies Reveal Autocatalysis by ZnX2 *.

We report a Ni-catalyzed regioselective arylbenzylation of alkenylarenes with benzyl halides and arylzinc reagents. The reaction furnishes differently substituted 1,1,3-triarylpropyl structures that are reminiscent of the cores of oligoresveratrol natural products. The reaction is also compatible for the coupling of internal alkenes, secondary benzyl halides and variously substituted arylzinc reagents. Kinetic studies reveal that the reaction proceeds with a rate-limiting single-electron-transfer process and is autocatalyzed by in-situ-generated ZnX2 . The reaction rate is amplified by a factor of three through autocatalysis upon addition of ZnX2 .

Ni‐Catalyzed Arylbenzylation of Alkenylarenes: Kinetic Studies Reveal Autocatalysis by ZnX2**

AbstractWe report a Ni‐catalyzed regioselective arylbenzylation of alkenylarenes with benzyl halides and arylzinc reagents. The reaction furnishes differently substituted 1,1,3‐triarylpropyl structures that are reminiscent of the cores of oligoresveratrol natural products. The reaction is also compatible for the coupling of internal alkenes, secondary benzyl halides and variously substituted arylzinc reagents. Kinetic studies reveal that the reaction proceeds with a rate‐limiting single‐electron‐transfer process and is autocatalyzed by in‐situ‐generated ZnX2. The reaction rate is amplified by a factor of three through autocatalysis upon addition of ZnX2.

Palladium-catalyzed cross-dehydrogenative-coupling of nitro-substituted internal alkenes with terminal alkenes

The palladium-catalyzed cross-dehydrogenative-coupling (CDC) reaction of internal alkenes (α-nitro ketene dithioacetals) and terminal alkenes (acrylates) was achieved in AcOH/DMSO using air or AgOAc as the sole oxidant. Styrenes were also applied in the CDC reaction of these internal alkenes with AgOAc as the oxidant. Polyfunctionalized 1,3- and 1,4-dienes were obtained in moderate to excellent yields under mild conditions, without prefunctionalization of the substrates. The diene products were readily transformed into the corresponding amines and derivatives.

Iron-Catalyzed Stereoconvergent Tertiary Alkylation of (E)- and (Z)-Mixed Internal Olefins with Functionalized Tertiary Alkyl Halides

Herein, we report an efficient method for the stereoconvergent tertiary alkylations of (E)- and (Z)-mixed internal olefins (styrenes, enamides, and vinylic ethers) to produce trisubstituted olefins bearing a quaternary carbon center via an addition/elimination reaction in the presence of an iron catalyst. (E)- and (Z)-mixed internal olefins with various E/Z ratios reacted smoothly with α-bromocarbonyls as a tertiary alkyl source to exclusively produce (E)-trisubstituted olefins. Mechanistic studies revealed that each of the (E)- and (Z)-internal olefins exhibited the same reactivity, and the exclusive generation of (E)-trisubstituted olefin products could be attributed to the β-hydrogen elimination of an alkyl iron species. The developed method can be used to synthesize highly congested trisubstituted olefins containing a quaternary carbon atom that bears various alkyl chains.

Base-mediated reactions of diethyl malonates derivatives with perfluorinated olefins: Novel synthetic routes to multifunctional ionomer precursors

A novel synthetic method for the preparation of per- and polyfluorinated unsaturated 2-substituted malonates is presented involving the deprotonation of the starting diethyl malonate by a strong base, followed by in situ addition of the C-nucleophile to the terminal double bond of the perfluorinated olefin. Subsequent elimination of the corresponding leaving groups and restoring of the double bond leads to the target bifunctional perfluorinated olefins. In the case of unsubstituted diethyl malonate, the elimination is accompanied by a prototropic rearrangement with a double bond migration and the addition of a second equivalent of the C-nucleophile forming the tetrafunctional internal olefins. The reaction conditions, factors affecting the reactivity and regioselectivity of the process, the choice of reagent as well as the course of competitive reactions are also discussed.

Effects of water salinity on the foam dynamics for EOR application

Factors limiting foam injection for EOR application are exceptionally low rock permeability and exceedingly high salinity of the formation water. In this regard, foam formation using internal olefin sulfonate is investigated over a wide salinity range (1, 5, 8, 10, and 12% NaCl) through 10 mD limestone. The relationships between pressure drop (dP), apparent viscosity, liquid flow rate, total flow rate, salinity, foam texture, and length of foam drops at the outlet used as an indicator of viscosity are studied. Foaming is observed up to 12% NaCl, compared to a maximum of 8% NaCl in similar core-flooding experiments with 50 mD limestone and 255 mD sandstone. Thus, the salinity limit of foam formation has increased significantly due to the low permeability, which can be explained by the fact that the narrow porous system acts like a membrane with smaller holes. Compared to the increasing dP reported for highly permeable rocks, dP linearly decreases in almost the entire range of gas fraction (fg) at 1–10% NaCl. As fg increases, dP at higher total flow rate is higher at all salinities, but the magnitude of dP controls the dependence of apparent viscosity on total flow rate. Low dP is measured at 1% and 10% NaCl, and high dP is measured at 5, 8, and 12% NaCl. In the case of low dP, the apparent viscosity is higher at higher total flow rate with increasing gas fraction, but similar at two total flow rates with increasing liquid flow rate. In the case of high dP, the apparent viscosity is higher at lower total flow rate, both with an increase in the gas fraction and with an increase in the liquid flow rate. A linear correlation is found between dP or apparent viscosity and liquid flow rate, which defines it as a governing factor of foam flow and can be considered when modeling foam flow.

Effects of internal hydrophilic groups of a newly developed sustainable anionic surfactant on biodegradability and ecotoxicity

Recently, a new sustainable anionic surfactant called bio-based internal olefin sulfonate (Bio IOS) has been developed. This surfactant enables excellent water solubility and high surface activity. It has a unique structure of long hydrophobic alkyl chains (C16 to C18) with two types of hydrophilic groups in its midsection, which distinguish it from other conventional anionic surfactants. However, the effects of the specific structural features of the surfactant on its environmental properties and the consequent effects on the environment remain unclear. In this study, we investigated the environmental fate and ecotoxicity of Bio IOS and the effects of the types and positions of hydrophilic groups on biodegradability and ecotoxicity. Biodegradation studies demonstrated that Bio IOS was readily biodegradable with >99.5% removal in wastewater treatment activated sludge (test concentration: 1 mg/L) and a fast half-life of 5.8 h in river water (test concentration: 10 μg/L); the excellent biodegradability was likely due to the high water solubility attributed to the internal hydrophilic groups. Meanwhile, moderately toxic effects were observed, whereby the 50% lethal and effect concentrations of the three freshwater species were above 1 mg/L. Ecotoxicity studies with different types and positions of hydrophilic groups revealed that hydroxyalkane sulfonate was less toxic and that toxicity was reduced in the presence of more internally located hydrophilic groups. These findings suggest that the hydroxyl group and the internal positions of hydrophilic groups that constitute the molecular configuration resembling two separate shorter alkyl chains may reduce the adverse effects on organisms despite the long alkyl chains.