One-pot Formation Research Articles

Open Sharing During COVID-19: CRISPR-Based Detection Tools.

Open Sharing During COVID-19: CRISPR-Based Detection Tools.

Photopatternable, Branched Polymer Hydrogels Based on Linear Macromonomers for 3D Cell Culture Applications.

Photochemical ligation strategies in hydrogel materials are crucial to model spatiotemporal phenomena that occur in the natural extracellular matrix. We here describe the use of cyclic 1,2-dithiolanes to cross-link with norbornene on linear poly(ethylene glycol) polymers through UV irradiation in a rapid and byproduct-free manner, resulting in branched macromolecular architectures and hydrogel materials from low-viscosity precursor solutions. Oscillatory rheology and NMR data indicate the one-pot formation of thioether and disulfide cross-links. Spatial and temporal control of the hydrogel mechanical properties and functionality was demonstrated by oscillatory rheology and confocal microscopy. A cytocompatible response of NIH 3T3 fibroblasts was observed within these materials, providing a foothold for further exploration of this photoactive cross-linking moiety in the biomedical field.

Asymmetric photocatalysis over robust covalent organic frameworks with tetrahydroquinoline linkage

The asymmetric photocatalytic organic synthesis (APOS) process is a sustainable and environmentally benign method for the production of optically active chemicals with sunlight as an energy source. However, it still lacks efficient semiconductors with tunable band structures and has a low recycling stability. Herein, we report the synthesis of tetrahydroquinoline-linked covalent organic frameworks (QH-COFs) with irreversible tetrahydroquinoline linkage as efficient semiconductors for the visible-light-driven asymmetric α-alkylation of aldehydes by merging with a chiral secondary amine. Up to 94% ee was obtained over QH-COFs, and the activity of QH-COFs was significantly higher than those of inorganic semiconductors (e.g., TiO2, BiVO4, and WO3) under similar conditions, which is mainly attributed to their narrow band gap and suitable band edge. As far as we know, QH-COFs are the most active semiconductors for asymmetric α-alkylation of aldehydes ever reported. The QH-COFs were prepared via a one-pot Povarov cascade imine formation and cycloaddition reaction using Sc(OTf)3/Yb(OTf)3 as Lewis acid catalysts. Attributed to the tetrahydroquinoline linkage, QH-COFs showed extremely high recycling stability, which made practicals application possible. This work not only opens up a new avenue for asymmetric photocatalysis but also provides an efficient and general method for the construction of robust COFs.

Increasing Complexity: A Practical Synthetic Approach to Three-Dimensional, Cyclic Sulfoximines and First Insights into Their in Vitro Properties.

A short synthetic approach with broad scope to access five- to seven-membered cyclic sulfoximines in only two to three steps from readily available thiophenols is reported. Thus, simple building blocks were converted to complex molecular structures by a sequence of S-alkylation and one-pot sulfoximine formation, followed by intramolecular cyclization. Seventeen structurally diverse cyclic sulfoximines were prepared in high overall yields. In vitro evaluation of these underrepresented, three-dimensional, cyclic sulfoximines with respect to properties relevant to medicinal chemistry did not reveal any intrinsic flaw for application in drug discovery.

Chemiluminescent microplate-based assay of DNA based on isothermal circular strand-displacement polymerization reaction (ICSDPR)

Sensitive microplate-based chemiluminescent assay coupled with isothermal circular strand-displacement polymerization reaction (ICSDPR) for DNA detection was developed. The assay sensitivity was improved using a triple amplification strategy based on employment of ICSDPR, streptavidin-polyperoxidase conjugate and an enhanced chemiluminescent reaction. To increase the accuracy all stages of the assay (one-pot format) were carried out in the same microplate well. The proposed assay detected the target DNA in fM-pM ranges and distinguish target DNA from related mismatched DNAs, demonstrating high sensitivity and high selectivity. This format is highly suitable for the development of sensitive and high-throughput kits of nucleic acids which can be easily automated.

Investigations on the nature of electrolyte on the electrochemical supercapacitor performance of heteroatom doped graphene

A rapid facile and one-pot formation of N-doped graphene by benzimidazole as a heterocyclic nitrogen source was explored by supercritical fluid technique. Here, we have investigated the electrochemical capacitance of N-doped graphene using various electrolytes. The availability of nitrogen-containing functionalities was scrutinized by FT-IR spectra. The type and quantity of N-doping were examined via elemental analysis and XPS, separately. Three various weight fractions of graphene oxide and benzimidazole were prepared. The electrochemical capacitance studies illustrated the N-doped graphene bearing 4.4 wt% of N achieved an improved capacitance of 256 F g−1 at 1 A g−1. The capacitive behavior for the full cell using two different aqueous electrolytes was performed and revealed an energy density of 12.3 Wh kg−1 in the aqueous solution of 1 M NaClO4 which was three times superior to 20% KOH solution (4.1 Wh kg−1) and in further the full cell examination in two different non-aqueous electrolytes, suggesting that the energy density accomplished in EMIMBF4 electrolyte at 0.2 A g−1 was found to be 30 Wh kg−1 which was superior to 1 M TBABF4 in acetonitrile (13.8 Wh kg−1).

One-pot microplate-based chemiluminescent assay coupled with catalytic hairpin assembly amplification for DNA detection.

Nowadays, considerable efforts are focused on advancing DNA detection methods, which are extremely important in clinical diagnostics, pathogen determination, gene therapy, and forensic analysis. A one-pot sensitive microplate-based chemiluminescent assay coupled with catalytic hairpin assembly (CHA) amplification for detection of a 35-mer DNA oligonucleotide was developed. To improve the assay sensitivity, a triple amplification strategy based on the application of CHA (1), streptavidin-polyperoxidase conjugate (Stp-polyHRP) (2), and an enhanced chemiluminescent reaction (3) was used. The one-pot format of the assay, where all steps of the DNA determination are performed in the same well without transfer of samples from one test tube to another, increased its precision. The proposed assay detected the target DNA in the fM range and distinguished the target DNA from related DNAs, demonstrating its high sensitivity and high selectivity. Moreover, the assay was applied successfully for the quantitative determination of the target in spiked samples of human plasma. A microplate format of the assay was convenient for the analysis of a large number of samples. This study provides a prospective tool for DNA detection. Graphical abstract.

A formal [3 + 2] annulation reaction of propargyl sulfonium compounds and N-ylides: access to pyrrolo[2,1-a]quinolines, pyrrolo[2,1-a]phthalazines and indolizines.

A sequential [3 + 2] annulation of prop-2-ynylsulfonium salt and N-ylides was developed, leading to the formation of a series of pyrrolo[2,1-a]quinolines, pyrrolo[2,1-a]phthalazines and indolizines. The protocol featured the simultaneous one-pot formation of three new C-C bonds in moderate yields under mild conditions. In this reaction, the prop-2-ynylsulfonium salts acted as the C2 synthons and sulfide served as the leaving group. The resultant products could serve as useful precursors for the synthesis of diverse chemical compounds.

Synthesis of 1-(methylsulfonyl)-1-propene and N,N-dimethyl-1-propene-1-sulfonamide

Various vinylsulfones and vinylsulfonamides have a wide range of biological activities (mainly, inhibition of different types of enzymes) and are frequently used in synthetic organic chemistry (as active dienophiles, Michael acceptors and, generally, active agents in 1,4‑addition and electrocyclization reactions). However, despite numerous synthesized substances of this type, the synthetic protocols for the obtaining of the low molecular weight representatives of these compounds – 1‑(methylsulfonyl)-1-propene and N,N‑dimethyl-1‑propene-1-sulfonamide – seem to be still little known. In the present work we report a simple, efficient and general protocol for the dehydrative synthesis of 1‑(methylsulfonyl)-1‑propene and N,N‑dimethyl-1‑propene-1‑sulfonamide starting from corresponding 1-(methylsulfonyl)-2-propanol and N,N‑dimethyl-2‑hydroxypropanesulfonamide, respectively, using MeSO2Cl/organic base system basing on the preliminary experiment of 2‑(4‑bromophenyl)-N,N‑dimethylethenesulfonamide synthesis from 2‑(4‑bromophenyl)-2‑hydroxy-N,N-dimethylethanesulfonamide. The latter in its turn has been obtained starting from N,N‑dimethylmethanesulfonamide by lithiation with n-BuLi, subsequent action of 4‑bromobenzaldehyde and further workup. The applied protocol of vinyl derivatives synthesis allows to avoid isolation of intermediate mesyl derivatives, consisting of one-pot formation of leaving group and its elimination. Accordingly to coupling constants in 1H NMR spectra, synthesized N,N‑dimethyl-1-propene-1‑sulfonamide exists as mixture of E- and Z-isomers (in the ratio 88:12), while isolated 1‑(methylsulfonyl)-1‑propene and 2-(4-bromophenyl)-N,N‑dimethylethenesulfonamide are the most stable E‑isomers. The structures of the synthesized compounds are confirmed by the methods of 1H NMR-spectroscopy and mass-spectrometry.

Combinatorial Enzymatic Synthesis of Unnatural Long-Chain β-Branch Pyrones by a Highly Promiscuous Enzyme.

In this study, we described in detail a combinatorial enzymatic synthesis approach to produce a series of unnatural long-chain β-branch pyrones. We attempted to investigate the catalytic potential of a highly promiscuous enzyme type III PKS to catalyze the non-decarboxylative condensation reaction by two molecules of fatty acyl diketide-N-acetylcysteines (diketide-NACs) units. Two non-natural long-chain (C16, C18) fatty acyl diketide-NACs were prepared successfully for testing the ability of non-decarboxylative condensation. In vitro, 12 novel naturally unavailable long-chain β-branch pyrones were generated by one-pot formation and characterized by ultraviolet–visible spectroscopy and high-resolution liquid chromatography–mass spectrometry. Interestingly, enzymatic kinetics result displays that this enzyme exhibits the remarkable compatibility to various non-natural long-chain substrates. These results would be useful to deeply understand the catalytic mechanism of this enzyme and further extend the application of enzymatic synthesis of non-natural products.

Indoles from Alkynes and Aryl Azides: Scope and Theoretical Assessment of Ruthenium Porphyrin-Catalyzed Reactions.

A symbiotic experimental/computational study analyzed the Ru(TPP)(NAr)2 -catalyzed one-pot formation of indoles from alkynes and aryl azides. Thirty different C3 -substituted indoles were synthesized and the best performance, in term of yields and regioselectivities, was observed when reacting ArC≡CH alkynes with 3,5-(EWG)2 C6 H3 N3 azides, whereas the reaction was less efficient when using electron-rich aryl azides. A DFT analysis describes the reaction mechanism in terms of the energy costs and orbital/electronic evolutions; the limited reactivity of electron-rich azides was also justified. In summary, PhC≡CH alkyne interacts with one NAr imido ligand of Ru(TPP)(NAr)2 to give a residually dangling C(Ph) group, which, by coupling with a C(H) unit of the N-aryl substituent, forms a 5+6 bicyclic molecule. In the process, two subsequent spin changes allow inverting the conformation of the sp2 C(Ph) atom and its consequent electrophilic-like attack to the aromatic ring. The bicycle isomerizes to indole via a two-step outer sphere H-migration. Eventually, a 'Ru(TPP)(NAr)' mono-imido active catalyst is reformed after each azide/alkyne reaction.

Unexpected one-pot formation of the 1H-6a,8a-epiminotricyclopenta[a,c,e][8]annulene system from cyclopentanone, ammonia and dimethyl fumarate. Synthesis of highly strained polycyclic nitroxide and EPR study.

The unexpected formation of a highly strained polycyclic amine was observed in a one-pot synthesis from cyclopentanone, dimethyl fumarate and ammonium acetate. This multistep reaction includes 1,3-dipolar cycloaddition of dimethyl fumarate to the cyclic azomethine ylide formed in situ from cyclopentanone and ammonia. The polycyclic amine product was easily converted into a sterically shielded polycyclic nitroxide. The EPR spectra and spin relaxation behavior of the nitroxide were studied in solution. The spin relaxation seems well suited for the use as a biological spin label and are comparable with those of cyclic nitroxides with two spirocyclic moieties adjacent to the N–O· group.

Constructing Robust Covalent Organic Frameworks via Multicomponent Reactions

Methodology development of robust linkages is fundamentally important for the synthesis and application of covalent organic frameworks (COFs). We report herein a new strategy based on multicomponent reactions (MCRs) to construct ultrastable COFs. With the one-pot formation of five covalent bonds in each cyclic joint, a series of imidazole-linked COFs were robustly constructed through the Debus-Radziszewski MCR from three easily available components. By reaching a higher level of complexity and precision in covalent assembly, this research explores a new direction in integrating sophisticated reversible/irreversible reactions to construct crystalline porous frameworks.

One-pot formation of magnetic layered double hydroxide based on electrostatic self-assembly to remove Cr(VI) from wastewater

Magnetic ZnAl-LDH composite materials (Fe3O4@LDH) based on the electrostatic attraction was manufactured by self-assembly method to remove Cr(VI) from wastewater simultaneously. Fe3O4 microspheres with suitable size can be surrounded by the LDH layers in the formation process to separate easily and reduce the dosage of Fe3O4. The removal behaviors of Cr(VI) from wastewater were investigated and the obtained samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopic (TEM) and molecular simulation. Equilibrium studies indicated that the experimental data was well described by Langmuir models and the removal was a charge-limited process. Compared with other reported papers, the removal capacity for Cr(VI) by this method was larger, revealing a maximum utilization of charges on LDH. By molecular simulation, the relationship among chemical bond, electron transfer and energy was explained microscopically and the removal mechanism was proved that Cr(VI) trapped onto Fe3O4@LDH involved ion electrostatic interaction. The reusability of Fe3O4@LDH composite was tested and illustrated that it can be reused for several times.

One-pot formation of sugar-immobilized monodisperse polymethylmethacrylate particles by soap-free emulsion polymerization

Soap-free emulsion polymerization was applied to fabricate monodisperse submicron-sized polymethylmetacrylate (PMMA) particles with β-D-glucopyranoside (glucose) groups immobilized on the surface. The immobilization was induced not by the direct surface chemical modification but rather by the coexistence of octyl-β-D-glucopyranoside dissolved in the starting water solvent. The presence of the immobilized glucose components on the particle surface was proven by the specific affinity for concanavalin A (ConA). Due to the hydrophobic nature of the PMMA matrix, the relatively hydrophilic glucose components tend to be oriented toward the outer aqueous phase, giving rise to the markedly increased adsorption of ConA, where the nonpolar octyl tail acts as the anchor to the relatively hydrophobic polymeric matrix.

One-Pot Formation of Sb-Carbon Microspheres with Graphene Sheets: Potassium-Ion Storage Properties and Discharge Mechanisms.

Low-cost rechargeable batteries are ardently required for large-scale energy storage applications. In this regard, nonaqueous potassium-ion batteries (KIBs) are ascendant candidates due to the abundance of potassium resources, yet their energy density and cycle stability are insufficient for practical use. In this study, we report the Sb-based multicomposite comprising Sb nanoparticles, amorphous carbon (C), and reduced graphene oxide (rGO) as an anode material for KIBs. By adopting the tartaric acid as a carbon source and a chelating agent simultaneously, a multicomposite electrode with uniform and fine-sized Sb particles is realized. The Sb-C-rGO multicomposite exhibits a reversible capacity of 310 mAh g-1 at 0.5 A g-1 and 79% of it is retained after 100 cycles. Electrochemical tests show that the capacity fading in the Sb-C-rGO cell is attributed to the side reactions in the K metal and electrolyte, rather than the degradation of Sb nanoparticles. Furthermore, the formation of the metastable product is elucidated by Ostwald's step rule and density functional theory calculations. The present synthesis approach and the understanding of the failure and working mechanisms provide general insight into developing the alloying-type electrode materials for rechargeable batteries.

Hexagonal sodium yttrium fluoride mesocrystals: One-pot hydrothermal synthesis, formation mechanism and multicolor up-/down-converted luminescence for anti-counterfeiting and fingerprint detection

Abstract Currently, a precise architecture manipulation of mesocrystals with controllable morphology and tunable size remains a huge challenge and is highly desired for their practical applications. Here, we develop a facile one-pot strategy for the direct synthesis of uniform and monodispersed β-NaYF4 mesocrystals with cantaloupe-like shape and adjustable dimension. To investigate the formative mechanism of β-NaYF4 superstructures in depth, the evolution processes for the crystal structure and morphology of β-NaYF4 mesocrystals under different experimental conditions have been systematically researched and discussed. A series of experimental results demonstrate that intrinsic crystallographic structure and external factors govern the crystal growth process of hexagonal-phased NaYF4. The processes of dissolution-renucleation, anisotropic growth, subsequent oriented attachment and self-assembly are believed to be responsible for the formation of cantaloupe-shaped β-NaYF4 mesocrystals. Moreover, the luminescence properties of β-NaYF4:RE3+ (RE = Ce, Tb, Eu, Yb, Tm and Ho) mesocrystals are also studied and efficient multicolor upconverting and downshifting emissions can be easily realized. As a proof of concept experiment, the as-synthesized β-NaYF4:RE3+ phosphors are employed to demonstrate their promising applications in anti-counterfeiting and fingerprint identification.

Terminal Alkyne-Assisted One-Pot Synthesis of Arylamidines: Carbon Source of the Amidine Group from Oxime Chlorides.

A terminal alkyne-assisted protocol for the one-pot formation of a diverse range of arylamidines from a novel cascade reaction of in situ generated nitrile oxides, sulfonyl azides, terminal alkynes, and water by [3 + 2] cycloaddition and ring opening sequence was developed. The use of aryl oxime chlorides as the carbon source of the amidine group and the addition of water proved to be critical for the reaction. Moreover, terminal alkynes, which can lead to high yields of products by employing a less amount, may play a catalytic role in the reaction. A broader range of substrates was investigated.

One-Pot Synthesis and Formation Mechanism of Hollow ZSM-5.

Coffin-shaped hollow ZSM-5 zeolite (HZZ) particles with shell thickness of about 200 nm and hollow diameter of approximately 1.5 μm were synthesized in one pot by using tetrapropylammonium bromide (TPABr), aluminum triisopropoxide Al[OCH(CH3 )2 ]3 and tetraethoxysilane (TEOS) as the structure-directing agent (SDA), aluminum and silica source, respectively. The appropriate molar ratios of TPABr/SiO2 and Si/Al as well as suitable crystallization temperature are the key factors for the formation of HZZ. The formation of the HZZ can be attributed to the existence of intrinsic density variation inside the initial amorphous aggregates and the Al zoning in the outer surface of the ZSM-5 particles. Amorphous silica with low crystallinity formed at early stages and low Al concentration, which has been subsequently dissolved and recrystallized on the ZSM-5 particle surface through Ostwald ripening, leading to the formation of HZZ. This approach, which uses a high concentration of SDA, will provide new possibilities and insight into the prospective fabrication of hollow zeolites.

A novel ‘bottom-up’ synthesis of few- and multi-layer graphene platelets with partial oxidation via cavitation

The transient cavitation of diaromatic components such as 1-methylnaphthalene has been used to produce graphene platelets in a ‘bottom-up’ synthesis via the high temperature (>5000 K) conditions that are generated inside collapsing bubbles. Acoustic cavitation produced yields of 5.7 × 10−11 kgJ−1 at a production rate of 2.2 × 10−9 kgs−1. This can be improved by generating cavitation hydrodynamically, thus making commercial scale production viable. Hydrodynamic cavitation produced platelets with larger lateral dimensions (≥2 µm) than those formed by acoustic cavitation (10–200 nm). The partially oxidised nature of the platelets enables their covalent chemical functionalisation, which was achieved by combining suitable molecules in the reaction medium to affect a one-pot formation and functionalisation of graphene.