Tertiary Carbonate Research Articles

Construction of Vicinal Quaternary Centers via Ru-Catalyzed Enantiospecific Allylic Substitution with Lithium Ester Enolates.

The installation of vicinal quaternary centers with absolute stereocontrol constitutes a considerable challenge in organic synthesis. Herein, we introduce a novel [Cp*Ru(MeCN)3]PF6/phenoxythiazoline catalyst system that achieves enantiospecific allylic substitution of tertiary carbonates with α,α-disubstituted lithium ester enolates to give products containing vicinal quaternary centers. Noteworthy features include the direct use of nonstabilized ester enolates, a class of nucleophiles which has rarely been used in transition metal-catalyzed allylic substitution reactions. The approach is demonstrated for a broad scope of tertiary electrophiles as well as ester enolates and accomplishes stereoretentive substitution with excellent conservation of ee (89-99%) and branched/linear regioselectivities (up to 40:1).

Reinterpretation of Salodik Group Performance Based on Facies and Diagenesis Approaches to Classify Reservoir Quality

An integrated study of several methods to characterize a carbonate reservoir provides a comprehensive result on carbonate facies and diagenesis. Therefore, a study on the Tertiary carbonate reservoir at the East Arm of Sulawesi area, Banggai – Sula Basin, is intended to determine the Salodik Group carbonate reservoir facies and diagenesis. Moreover, the purpose of this study is to determine the intensity and implication of syn-depositional or post-depositional processes, and to provide the reservoir final properties values, such as porosity and permeability to classify the reservoir quality. The methods of the study are based on carbonate fieldwork mapping to obtain samples on distributed traverses. Further analyses are the laboratory works to determine facies and diagenesis features on a more detailed scale. This study shows several facies, dominantly classified into reefal packstone, planktonic foraminifera packstone-wackestone, large foram packstone-mudstone, skeletal packstone-wackestone, planktonic-large foraminifera packstone-wackestone, and large foraminifera-red algae packstone. The dominant diagenesis processes are cementation and dissolution. Moreover, meteoric vadose and meteoric phreatic are predominantly the main diagenesis environment of Salodik Group formations. Furthermore, the dominant diagenesis stage is Eogenetic. The post-depositional process or the diagenetic processes, provides a more significant impact on carbonate reservoir properties than the syn-depositional process as shown on lithofacies texture. However, in general, from the younger to the oldest formation of Salodik Group, this shows a decreasing trend of reservoir properties due to the dominantcementation process in the oldest formation. Overall, the reservoir quality referring to porosity value is classified as negligible to excellent. While, based on permeability data, it is classified as the tight to good reservoir.

Exploring carbonate reservoirs potential, north Egypt

Carbonate reservoirs contain a significant portion of the world's oil reserves. The Middle East is home to many of these reservoirs. Carbonate reservoirs can be found in a few very large oil fields, including Egypt's Zohr field, the largest conventional gas field in Egypt. In this article, we present a couple of successful tertiary carbonate reservoirs that are bearing hydrocarbon in the Egyptian Western Desert and Gulf of Suez provinces, they are distributed across Egypt's subsurface, and they are characterized by heterogeneous porosity and permeability. These heterogeneities are caused by the wide spectrum of tectonostratigraphic environments in which carbonates are deposited and by subsequent diagenetic alteration of the original rock fabric. The structural analysis of the study areas based on the interpretation of both geophysical and geological data, in JD, Abu Sennan, and the North Amer areas in the Western Desert and offshore Gulf of Suez respectively showed that tectonostratigraphic history during tertiary time affected a great extent carbonate reservoir quality. Major fault trends formed secondary fracture porosity possibly allowing hydrothermal solutions to pass through the reservoirs and form secondary vuggy porosity. These characteristics are considered important factors of promising carbonate reservoirs. In this study, several carbonate reservoirs have been outlined. The study workflow helped us better identify carbonate prospects with high fractured density.

Predicating of Formation Pore Pressures in Tertiary Reservoirs Using Geophysical Wireline Log Data

Changes to certain geophysical characteristics, such as sonic transit time with depth, indicate the pressure system of over-pressured zones. In this study, well-log data is used to investigate the distribution of formation overpressures in the tertiary reservoirs of one Iraqi oil field. Three wells located within the tertiary carbonate reservoir of one Iraqi oil field are of interest in this study. To assess the reservoirs, a petrophysics log analysis was carried out. The reservoir's intervals are the area of interest. The sonic velocity data was used to create a normal compaction trend line, and the overpressure zones were identified by observing the reversals in the normal compaction trend line. The pore pressure, fracture pressure, and gradients were calculated using the Eaton method. The method relies on the correlation between the normal transit time found on the normal compaction trend and the observed transit time from the log reading. The sonic log determines the bulk density and matches the density derived from the density log. Abnormal pressures were identified primarily within the area of interest, especially with unit B in Well 1. In Well 2, the abnormal pressures were recognized in zones above the area of interest. Abnormal pressures in Well 3 were identified primarily within all areas of interest. The importance of this work is to help predict overpressure zones in the research area before drilling or workover.

Determine the Reservoir Characterization, Using Seismic Data, Well Logs, Attribute Interpretation, and Static Modelling in the Duhok Province, Kurdistan Region, Iraq

Although the High Folded Zone in the Kurdistan Region of Iraq forms part of the Zagros-Taurus Folds and Thrust belt considered one of the potential hydrocarbon provinces, the oil fields within the zone are still lacking in geophysical exploration and scientific research. So, the rationale behind this study is the prospecting and evaluation of one of the Tertiary carbonate reservoirs at the “WN” oil field in the Duhok area by integrating the 3D seismic and well-log data. The methodology covered seismic interpretation, well logs and their relevant petrophysical analysis, attribute computation, and 3D static property modeling. The constructed reservoir maps revealed a double-plunging rollover anticlinal structure trending in the East-West direction parallel to the Taurus Mountain series. A total of nineteen minor reversal faults trending E-W to ENE-WSW dissecting the northern limb of the anticline were manually interpreted. The isopach map shows various thicknesses ranging from 160 to 330 m, averaging 245 m. The property models show the limited values of their parameters as the effective porosity is limited (0.97-23%), the secondary porosity (0.43-11.7%), permeability (0.00-238.8 mD), the water saturation (12.44-99.8%), and the clay volume (0.00-9.8%). The results of this research indicate that the horizon is a promising reservoir characteristic.

Application of stable isotopes, mixing models, and K-means cluster analysis to detect recharge and salinity origins in Siwa Oasis, Egypt

Waterlogging, soil salinization, and groundwater depletion in non-rechargeable aquifers are among the causes endangering the sustainability of Siwa Oasis. The water resources include the tertiary carbonate aquifer (TCA), Nubian sandstone aquifer (NSSA), springs, drains, and hypersaline lakes. Geophysical logs were used to identify various aquifer systems. Stable isotopes, major ions, and heavy metals were examined. K-means cluster analysis based on principal component analysis (PCA), hydrochemistry, stable isotopes, and mixing models using NETPATH were applied in order to understand the complex hydrogeological conditions in the different aquifer systems. The results showed that all water samples were under-saturated (SI < 1) with respect to anhydrite, halite, and gypsum minerals, indicating the water's ability to dissolve more from these minerals and increase water salinity.In contrast, calcite, dolomite, Ca-montmorillonite, and illite minerals were supersaturated in most water samples (SI > 1), showing their ability to precipitate these minerals. There is no recharge for the aquifer systems, and all the groundwater resources have paleo meteoric origin, where the maximum values of δ18O and δ2H are −8.45 and −65.63, respectively. All of the springs originated from the TCA, as indicated from the K-mean cluster analysis. There is a rapid increase in the water salinity of the TCA from 1998 to 2022 due to evaporation, rock weathering, mixing with old trapped sea water, and seepage of saline water from salt lakes. The significant variations in the water salinity of the TCA aquifer are due to the mixing between fresh water of NSSA (dilution) and salt water from Zeituna and Siwa lakes through downward flow in some locations, where over-extraction of water for irrigation purposes has decreased the water pressure in the TCA. The mixing model confirmed salt lakes' contribution in increasing the TCA salinity by 2%–4%. Mixing water from TCA and NSSA could be the best management of the water resources in Siwa Oasis, as well as the application of subsurface drip irrigation.

Mechanism of palladium-catalyzed allylic substitution of tertiary allylic carbonates with sodium sulfinates: unusual bifunctional nucleophile-enabled inner-sphere pathway and origin of regio- and enantioselectivities

DFT calculations were performed to investigate Pd-catalyzed allylic sulfonylation of tertiary allylic carbonates. The bifunctional role of the sulfonate nucleophile enables the C–S bond formation via a unique inner-sphere pathway.

Experimental and Computational Studies on Cobalt(I)‐Catalyzed Regioselective Allylic Alkylation Reactions

AbstractHere, we report the development of cobalt(I)‐catalyzed regioselective allylic alkylation reactions of tertiary allyl carbonates with 1,3‐dicarbonyl compounds. A family of well‐defined tetrahedral cobalt(I) complexes bearing commercially available bidentate bis(phosphine) ligands [(P,P)Co(PPh3)Cl] are synthesized and explored as catalysts in allylic alkylation reactions. The catalyst [(dppp)Co(PPh3)Cl] (dppp=1,3‐Bis(diphenylphosphino)propane) enables the alkylation of a large variety of tertiary allyl carbonates with high yields and excellent regioselectivity for the branched product. Remarkably, this methodology is selective for the activation of tertiary allyl carbonates even in the presence of secondary allyl carbonates. This contrasts with the selectivity observed in cobalt‐catalyzed allylic alkylations enabled by visible light photocatalysis. Mechanistic insights by means of experimental and computational investigations support a Co(I)/Co(III) catalytic cycle.

Experimental and Computational Studies on Cobalt(I)-Catalyzed Regioselective Allylic Alkylation Reactions.

Here, we report the development of cobalt(I)-catalyzed regioselective allylic alkylation reactions of tertiary allyl carbonates with 1,3-dicarbonyl compounds. A family of well-defined tetrahedral cobalt(I) complexes bearing commercially available bidentate bis(phosphine) ligands [(P,P)Co(PPh3 )Cl] are synthesized and explored as catalysts in allylic alkylation reactions. The catalyst [(dppp)Co(PPh3 )Cl] (dppp=1,3-Bis(diphenylphosphino)propane) enables the alkylation of a large variety of tertiary allyl carbonates with high yields and excellent regioselectivity for the branched product. Remarkably, this methodology is selective for the activation of tertiary allyl carbonates even in the presence of secondary allyl carbonates. This contrasts with the selectivity observed in cobalt-catalyzed allylic alkylations enabled by visible light photocatalysis. Mechanistic insights by means of experimental and computational investigations support a Co(I)/Co(III) catalytic cycle.

Degradation of modified polystyrenes having degradable units by near‐infrared light irradiation

AbstractModified polystyrenes having tertiary ether linkages or carbonate linkages were degrade by irradiation of near‐infrared light (NIR) and subsequent heating. The polymer films containing a photoacid generator and commercially available photon upconversion nanoparticle (UCNP) were decomposed to form isobutene and/or carbon dioxide by irradiation of NIR and subsequent heating. The thermal decomposition behaviors of the polymers were investigated and discussed in terms of the chemical structures of degradable units. The thermal stability of the polymers was found to be in the order: tertiary ester &gt; tertiary carbonate. We believe that the degradation of NIR and subsequent heating contributes easy recycling of composite materials.

(Invited) Isotopic Labeling of Carbonate Solvents for Mechanistic Insights into Battery Gassing and Gas Reduction By Fluorinated Organosilanes

During cycling and high temperature storage, conventional lithium-ion electrolytes degrade through mechanisms that can lead to insoluble electrode surface films, solution-phase products, and gaseous species. Gas degradation products can cause significant cell swelling, leading to performance and safety problems. Innovations in electrolyte materials that can reduce gassing are highly desired, and gaining a greater understanding of the mechanisms of gas generation can further inform electrolyte development and optimization for reduced gassing.Fluorinated organosilicon (OS) compounds developed by Silatronix® have been studied in lithium-ion batteries, and their inclusion in the electrolyte has been shown to dramatically reduce gassing, as well as increasing cycling stability in nickel-rich battery systems.1 In this prior study, the gas species were identified and quantified, but the mechanistic origin of each gas remained unknown, Therefore, the mechanism of gas reduction by OS, as well as the effects of varying the OS molecule structure, required more investigation.In this study, isotopic labeling of multiple electrolyte components is used to provide insight into the origin of gas products, and the nature of gas reduction by several different OS materials. In a previous study, Silatronix® used 13C-labeled ethylene carbonate (EC) to identify the gases produced from EC during the battery’s first charge, as well as during high temperature storage.2 This follow-up investigation expands the 13C-labeled electrolyte components to include diethyl carbonate (DEC) and dimethyl carbonate (DMC) in addition to EC. Tertiary carbonate blends are used, each containing one 13C-labeled carbonate solvent blended with two unlabeled carbonates. Carbonate-only electrolytes are also compared to electrolytes with several different OS compounds added to the labeled carbonate formulations. NMC811/Gr pouch cells are charged and stored at high temperature, followed by gas generation measurements. GC-MS is used to analyze the gas components, labeled and unlabeled, generated in the battery pouch cells. Gases coming from EC, DEC, and DMC are each identified and quantified. The results show that all OS-containing cells have significant reductions in gas volume (-63%) compared to the carbonate-only cells, primarily through decreasing CO2. The quantification of gases shows that the largest fraction of solvent-generated CO2 comes from EC. All labeled gas species and quantities originating from each labeled carbonate are presented, and the effects of OS on the gases and their source carbonate components are shown, as well as the effect of different OS structures on gas reduction. Overall, this study illuminates in detail the origins of gassing from each of three common carbonate solvents when combined in a complex electrolyte formulation, and demonstrates that organosilicon materials are effective gas-reducing electrolyte components.

Green Chemistry Approach toward the Regioselective Synthesis of α,α-Disubstituted Allylic Amines.

Molybdenum-catalyzed allylic substitution reactions are known to provide direct and practical ways to construct new carbon-carbon bonds and privileged compounds. However, due to the lack of reports on carbon-heteroatom bond formation as a common deficiency, these reactions still face a great challenge. Described herein is a robust and convenient molybdenum-catalyzed regioselective allylic amination of tertiary allylic carbonates with an amine as the heteroatom nucleophile. Both aromatic and aliphatic amines react with various tertiary allylic alcohol derivatives to deliver the desired α,α-disubstituted allylic amines in high yield with complete regioselectivity. In addition, ethanol as the green solvent, a recyclable catalyst system through simple centrifugation techniques, and simple handling procedures make the current approach green, economic, and sustainable.

Vinyl acetate polymers modified by siloxane for improving reinforced concrete: Water proofness and anticorrosion

Concrete, which is commonly destroyed by erosion in adverse environments, cannot satisfy the demands of foundation construction engineering applications. The optimal wayto ensure concrete's durability is to cover its surface with a barrier coating that prevents potentially harmful particles from penetrating the inside. Vinyl acetate polymers were applied as coatings owing to excellent flexibility and strong adhesion to the substrate. However, their hydrophilicity and low hardness will inevitably limit the usage in various areas, in particular the construction materials field. In this study, a method of modifying vinyl acetate polymers (PVAc) by vinyl triethoxysilane (VTES) and vinyl neononanoate (VeoVa-9), vinyl neodecanoate (VeoVa-10) in tertiary vinyl carbonates was reported to enhance the anticorrosion of concrete, where the former VTES could act a coupling agent, while the latter tertiary vinyl carbonates provide shielding against invasion through steric effect. Following modification, the hydrophilic PVAc becomes a hydrophobic coating with a contact angle as high as 98°; the coating's water absorption rate in one week is merely 1.25%; higher hardness and modulus were validated by nanoindentation measurements, while sandpaper friction and lap-shear trial indicated an enhancement in wear resistance and adhesion; three-electrode electrochemical analysis revealed that the modified coating has a 98% anti-corrosion efficacy, and its excellent anticorrosion performance is further confirmed by 480-hour salt spray test on reinforced concrete models.

Testing the potential of drowned shore platforms as sea level proxies in a temperate, microtidal environment: Victoria, Australia

Shore platforms are erosional benches, often found at the base sea cliffs, which form through erosion concentrated within the intertidal zone. In locations without suitable depositional proxies, these erosional landforms have been used to reconstruct past sea levels. The precision and accuracy of shore platforms as sea level proxies is highly variable as their morphology, particularly their vertical position in the intertidal zone, is modulated by boundary conditions especially those related to the geology in which they are formed. In this study the semi-horizontal shore platforms on the microtidal temperate coast of Victoria, Australia are examined to test the utility of these systems as sea level indicators. These results are then applied to a suite of submerged shore platforms found offshore using high-resolution LiDAR topographic and multi-beam sonar bathymetric data. The elevation of both the contemporary and drowned platforms are measured at both the cliff-platform junction and the mid-point of each profile line. Both methods are compared to assess their utility to represent sea level at the time of their formation. It is found that those platforms formed within resistant sandstone and basalt are the best proxies for sea level forming in the upper intertidal zone, while those formed in softer Tertiary carbonates are less precise being predominately subtidal features. The morphology of the drowned platforms is broadly similar to those at current sea level elevations, and they are concentrated at a depth 49.7 to 57.2 m below modern sea level. It is inferred that these drowned platforms likely formed during marine isotope stage 5a or 5d.

Organocatalytic allylic alkylation of alkyne-substituted MBH carbonates: access to quaternary carbon-containing 1,4-enynes.

A DABCO-catalyzed allylic alkylation of tertiary propargylic alcohol-derived MBH carbonates with nitromethane was developed. A series of substituted 1,4-enynes with an all-carbon quaternary stereocenter were efficiently obtained in moderate to high yields. The synthetic utility of the product was demonstrated by facile synthesis of 1,4-enyne-embedded 2-pyrrolidinones.

Transportation of sediments by floating processes from southern Europe to the coastal regions of eastern Libya: Pumice rock fragments from at Tariyah and Qasr Libya coasts1

Abstract&#x0D; Fragments of pumice of various sizes and roundness were found mixed with recent coastal sediments of calcareous sand, calcareous granules, and shells in At Tariyah coast southwest of Benghazi, and in the coastal area of Qasr-Libya, Al Jabal Al Akhdar, northeastern Libya. The source area for the pumice fragments appears to be the active volcanic regions of eastern and southern Sicily; Etna volcano and submarine volcano known as the CampiFlegrei del Mar di Sicilia respectively. &#x0D; The pumice must have traveled a distance of at least 1000km across the Mediterranean Sea as a floating load. &#x0D; The recent coastal sediments of the Al Jabal Al Akhdar area are derived mainly from two different sources; a southern proximal source consisting of a well-exposed sequence of Tertiary carbonate rocks that produced well-sorted sand-size fragments and a northern distal source that produced cobble-size fragments of pumice. &#x0D; The mechanism of transporting sediments by floating as a floating load, from one sedimentary basin to another is completely different from the other well-known and documented methods of bedload and suspended load. Floating fragments can be transported for long distances and finally deposited without appreciable changes in size, roundness, shape, or sorting. Pumice deposited on the eastern coast of Libya indicates that long-distance transport produces minimal or negligible changes in the textural parameters of floating load components.

From neogene thin-skin to recent thick-skin deformation in Haiti fold-and-thrust belt (Western Hispaniola)

Haiti lies along the North Caribbean plate boundary, marked by two major left-lateral strike-slip faults. A southwest-verging Trans-Haitian fold-and-thrust belt (FTB), mostly affecting tertiary carbonate platform, developed in central Haiti between the two faults, south of the Massif du Nord and the San Juan–Los Pozos Fault Zone, as a result of north-south shortening. The large NW-SE antiformal Gonâve Island and Ridge mark the southwest termination of the FTB as it encountered the Southern Peninsula and Enriquillo-Plantain Garden Fault Zone. We show that this collision resulted in a tightening of the deformed wedge and thrust faults rooted deeper into the crust, leading to a transition from thin-skinned to thick-skinned tectonics in the Pliocene. These short- (3–6 km) and long- (15–30 km) wavelength folding deformations are temporally distinct in the north and more concomitant in the south, where compressional thin-skinned deformation is still active. The thick-skinned shortening was mostly expressed during the Quaternary, as shown by the formation of folds and uplift of terraces between 1.7 Ma and today. This thick-skinned detachment is characterised by a stronger imprint of strike-slip component, dragging the FTB to a more E-W direction in its northwest and southeast extremities. Understanding of the fault zone geometry of the recent 2010 Haiti earthquake (M = 7.2) could be reconsidered in the light of this tectonic transition.

Magnetotelluric data analysis using 2D inversion: A case study from Al-Mubazzarah Geothermal Area (AMGA), Al-Ain, United Arab Emirates

Geothermal manifestations (hot springs) emerge in the Al-Mubazzarah Geothermal Area (AMGA), Al-Ain city, Abu Dhabi Emirate, United Arab Emirates. This paper presents the application and results of a Magnetotelluric (MT) survey, which was carried out in 2017 at the AMGA geothermal field. The MT method was used to investigate the variations in the electrical conductivity beneath the AMGA. This study focuses on characterizing the patterns of subsurface electrical conductivity of the AMGA geothermal reservoir. Dimensionality analysis of the measured MT data indicate that 2D inversion is appropriate for the subsurface resistivity interpretation. The inversion results support a model consisting of three resistivity-defined layers; from top to bottom they are: (1) a shallow layer with resistivity ranging from 10 to 20 Ωm, representing recent alluvial and windblown deposits, (2) a second conductive layer with resistivities less than 10 Ωm, beneath the first layer. This layer is recognized as the Tertiary carbonate sequence in the region, (3) a deep, moderate to relatively high resistive zone, 10–30 Ωm beginning at 800 m depth and reaching 4 km depth in the northern part of the profile, representing Mesozoic basement rocks. The observed moderate to high resistivity zone (10–30 Ωm) in the 2D model may represent a region where the hot groundwaters originated (geothermal reservoir), with the hottest geothermal located at a depth greater than 4 km. The geothermal reservoir zone is also represented by a low to high density contrast and a low to moderate magnetic susceptibility, as indicated in the inverted potential field data models, and confirmed the existence of a north dipping major fault.

Rhodium-Catalyzed Stereospecific Cyanomethylation of Tertiary Allylic Carbonates

Rhodium-Catalyzed Stereospecific Cyanomethylation of Tertiary Allylic Carbonates

Regioselective and Stereospecific Rhodium-Catalyzed Allylic Cyanomethylation with an Acetonitrile Equivalent: Construction of Acyclic β-Quaternary Stereogenic Nitriles.

A highly regioselective and stereospecific rhodium-catalyzed cyanomethylation of tertiary allylic carbonates for the construction of acyclic β-quaternary stereogenic nitriles is described. This protocol represents the first example of a metal-catalyzed allylic substitution reaction using a triorganosilyl-stabilized acetonitrile anion, which permits access to several carbonyl derivatives that are challenging to prepare using conventional pronucleophiles. The synthetic utility of the stereospecific cyanomethylation is further exemplified through the construction of an intermediate utilized in the total synthesis of both (-)-epilaurene and (-)-α-cuparenone.