Article
Chemistry, Organic
Donghui Guo, Qiupeng Peng, Bei Zhang, Jian Wang
Summary: The novel method described in this report allows for the atroposelective generation of axially chiral amino esters using hemiaminals formed in situ, with a wide substrate scope, good functional group tolerance, and rapid assembly of axially chiral amino esters with high enantioselectivities in good to high yields.
Article
Chemistry, Physical
Muhammad Hassan, Raqiqa Tur Rasool, Ghulam Abbas Ashraf, Miao Lv, Abeer A. AlObaid, Suwanna Kitpati Boontanon, Zhengjun Gong
Summary: In this study, CoFe2-xMoxO4 heterogeneous catalysts were prepared and used as peroxymonosulfate (PMS) activators for the degradation of p-phenol sulfonic acid (PSA). The results showed that CoFe2-xMoxO4/PMS exhibited efficient catalytic degradation performance under the reaction conditions, and the Mo content had a positive correlation with catalytic activity, indicating the potential application of this catalyst for recalcitrant pollutant remediation.
SURFACES AND INTERFACES
(2023)
Article
Chemistry, Applied
Agata Wawrzynczak, Sylwia Jarmolinska, Izabela Nowak
Summary: In this study, ordered nanostructured KIT-6 silica with different numbers of sulfonic groups were synthesized. The amount of the functional group precursor used affected the structural and textural parameters of the synthesized materials. The samples modified by grafting exhibited a stable mesoporous structure, while the ones synthesized by co-condensation showed characteristics of KIT-6 materials. The developed synthesis procedures yielded potential solid acid catalysts with desirable catalytic performances.
Article
Polymer Science
Panagiotis G. Falireas, Jean-Michel Thomassin, Antoine Debuigne
Summary: This study introduces the first imidazolium-catalyzed epoxy vitrimers, which can be reshaped and recycled through catalyzed associative transesterification reactions, demonstrating their potential as catalysts in the field of adaptable networks and expanding the scope of vitrimers with the large variety of ILs and IL-catalyzed reactions.
EUROPEAN POLYMER JOURNAL
(2021)
Article
Chemistry, Organic
Uttam Dhawa, Robert Connon, Joao C. A. Oliveira, Ralf Steinbock, Lutz Ackermann
Summary: The asymmetric ruthenium-catalyzed C-H alkylations were achieved using a chiral C2-symmetric carboxylic acid, resulting in chiral tetrahydrocarbazoles and cyclohepta[b]indoles with high enantioselectivity at room temperature. Mechanistic studies revealed a fast C-H ruthenation process, with a rate- and enantio-determining proto-demetalation step. The asymmetric induction was governed by weak attractive secondary dispersion interactions, as shown in NCI analysis of the key transition states.
Article
Chemistry, Physical
Ashok Ramakrishnan, Stefan G. Romeijn, Elisabeth Bouwman
Summary: This article describes an efficient and additive-free palladium catalyzed hydrocarbonylation reaction of alkenes using carboxylic acids as nucleophiles. Acid anhydrides are obtained in moderate to excellent yields. The relative concentrations of substrate and reagents play a crucial role in driving the reaction forward, reaching an equilibrium at equimolar concentrations under a given CO pressure. The use of electron-poor phosphine ligands is essential for obtaining higher rates of the catalytic reaction, and various substrates, including unactivated alkenes, were successfully converted to symmetric and mixed anhydrides.
JOURNAL OF CATALYSIS
(2023)
Article
Food Science & Technology
William Cardoso Lima, Leandro S. Oliveira, Adriana S. Franca
Summary: This study developed a low-cost adsorbent with a chemically modified surface bearing sulfonic groups using sunflower crop residue, which showed advantages in adsorption of phenylalanine. Optimization results indicated a higher adsorption capacity under specific conditions.
Article
Chemistry, Multidisciplinary
Yohei Shimizu, Motomu Kanai
Summary: In this article, we discuss the boron-catalyzed alpha-functionalizations of carboxylic acids developed in our group, including five reaction types. The reversible boron carboxylate formation plays a crucial role in the acidification of alpha-protons and enolization using mild organic bases, enabling chemoselective and asymmetric bond formations of carboxylic acids. We summarize the ligand effects on reactivity and stereoselectivity, substrate scopes, and mechanistic insights.
Article
Chemistry, Multidisciplinary
Mengsheng Li, Jing Zhang
Summary: Efficient strategies for accessing nitriles from common organic functionalities are of great importance in synthetic and medicinal chemistry. This study presents an iron-catalyzed deoxynitrogenation strategy to convert carboxylic acids into nitriles. The method utilizes a cyanamide as the recyclable nitrogen donor and deoxygenating reagent, and can be applied to aryl, alkenyl, and alkyl carboxylic acids without the need for inert gas protection. The practicality of this method is demonstrated through its application in late-stage modification of drug molecules, synthesis of a pharmaceutical structure, and scaleup reactions and downstream derivatizations.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Physical
Yan Li, Xiangpeng Lin, Cheng Zhang, Qiu Zhuang, Wei Dong
Summary: The study synthesized magnetic polydopamine sub-microspheres with sulfonic acid groups for removing tetracycline antibiotics. The maximum adsorption capacity reached 138.98 mg/g, with Langmuir isotherm and pseudo-second-order kinetic model fitting the equilibrium adsorption data. The adsorbent showed good performance even after six cycles, making it a promising option for wastewater treatment.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2021)
Article
Materials Science, Multidisciplinary
Zi-Han Zhao, Da-Peng Wang, Jing-Lin Zuo, Cheng-Hui Li
Summary: The study designed and synthesized a phenol compound with three hydroxyl groups, successfully fabricating a series of strong and tough elastomers with self-healing capacities, providing a new approach for synthesizing durable and functional self-healing materials.
ACS MATERIALS LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Mathias Schelwies, Rocco Paciello, Ralf Pelzer, Wolfgang Siegel, Michael Breuer
Summary: A direct carbonylation of allylic alcohols has been achieved for the first time with high catalyst activity at low CO pressure. The activation of the substrate by catalytic amounts of carboxylic anhydride, constantly regenerated with CO, plays a key role in the reaction. The identified reaction conditions are transferable to other substrates, opening up new possibilities in synthesis.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Physical
Fan Yang, Ruimin Shi, Hongliang Huang, Zhengqing Zhang, Xiangyu Guo, Zhihua Qiao, Chongli Zhong
Summary: Researchers have developed a highly proton-conducting material by grafting sulfonic groups onto the nanochannels of metal-organic frameworks. This material exhibits enhanced water adsorption behavior, proton-donating capability, and significantly higher proton conductivity compared to the pristine material, providing a new avenue for constructing proton-conducting materials.
ACS APPLIED ENERGY MATERIALS
(2022)
Article
Chemistry, Physical
Amit Singh Adhikari, Soumen Pandit, Ruchir Kant, Nilanjana Majumdar
Summary: An efficient method for highly selective allylic substitution of vinylcyclopropanes using carboxylic acids via iridium catalysis has been developed, providing a high yield of synthetically useful chiral building blocks. The practical application of the products in useful transformations demonstrates its utility.
Article
Polymer Science
Klara M. Saller, Gernot Hubner, Clemens Schwarzinger
Summary: In this study, a selective reaction method was developed to introduce free carboxylic acid groups into industrial polyester production, providing a new approach for the development of biodegradable polyester polymers. The reaction behavior was thoroughly investigated using a multimethod approach, allowing further applications in drug delivery, hydrogels, superabsorbers, coatings, dispersants, and wastewater treatment.
EUROPEAN POLYMER JOURNAL
(2023)
Article
Chemistry, Physical
Olessya P. Loiko, Johan P. A. Heuts, Alex M. van Herk
Summary: This article reports the synthesis of polymer-vesicle latex particles using extruded vesicles of DODAB via an atom transfer radical polymerization-based approach. Cryo-TEM characterization reveals that the final morphology of the particles is affected by monomer feed composition and chain length. Protrusions or nanocapsules were synthesized depending on the monomer combinations used.
COLLOID AND POLYMER SCIENCE
(2022)
Article
Biochemistry & Molecular Biology
Jie Liu, Ying Zhang, Kim van Dongen, Chris Kennedy, Maaike J. G. Schotman, Patricia Marin San P. Roman, Cornelis Storm, Patricia Y. W. Dankers, Rint P. Sijbesma
Summary: Two synthetic supramolecular hydrogels, formed from bis-ureaamphiphilescontaining lactobionic acid (LBA) and maltobionic acid (MBA) bioactiveligands, are applied as cell culture matrices in vitro. They mimic essential features of the extracellular matrix, self-assembling into long supramolecular fibers that form hydrogels. The hydrogels exhibit different stiffnesses and excellent bioactive properties in hepatic cell cultures, promoting spheroid formation. These results highlight the potential of carbohydrate-functionalized hydrogels for liver tissue engineering.
Review
Chemistry, Physical
Yunfei Guo, Mikko Muuronen, Frederic Lucas, Rint P. P. Sijbesma, Zeljko Tomovic
Summary: The formation of isocyanurate via cyclotrimerization of isocyanates is widely reported to provide polyurethane materials with improved properties. The review summarizes catalysts for the cyclotrimerization of isocyanates, categorizing them into two main classes and providing detailed information on catalyst structures, reaction conditions, and trimerization efficiency. The review aims to stimulate the design of more efficient catalysts and further understanding of the trimerization mechanism.
Article
Polymer Science
Annelore Aerts, Stan F. S. P. Looijmans, Lambert C. A. van Breemen, Rint P. Sijbesma, Johan P. A. Heuts
Summary: Mechanofluorescent polymer probes were used to visualize stresses and bond scission in polystyrene and polycarbonate. Activation of polystyrene probes with a molar mass of 1.1 x 10(5) g center dot mol(-1) in solution reached 30% after 1 h of sonication, while shorter probes showed lower activation percentages. Friction tests on mechanophore-containing polystyrene and polycarbonate films revealed crack formation and activation patterns correlated with friction force, penetration depth, and mechanophore activation.
Article
Materials Science, Multidisciplinary
Yunfei Guo, Julian Kleemann, Rint P. Sijbesma, Zeljko Tomovic
Summary: Polyurethane (PU) is commonly used in various applications, and improving its thermal stability and flame retardancy is critical. This study successfully introduced polyisocyanurate (PIR) and phosphorus motifs into polyurethane through a co-trimerization reaction, resulting in high thermal stability and flame retardancy. The method has potential applications in rigid PU foams and compact thermosets.
ACS APPLIED POLYMER MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Yunfei Guo, Anna M. M. Cristadoro, Julian Kleemann, Stefan Bokern, Rint P. P. Sijbesma, Zeljko Tomovic
Summary: Polyurethane can be modified with thermally stable aromatic imide structures to enhance its mechanical and thermal properties. In this study, imide-containing isocyanate-terminated prepolymers were synthesized in solvent-free conditions and used to prepare PUI elastomers with improved char formation and stiffness. The aromatic PUI elastomer also showed enhanced flame retardancy. This work demonstrates the potential use of imide prepolymers in high thermal stability and flame retardant PU applications.
ACS APPLIED POLYMER MATERIALS
(2023)
Article
Polymer Science
Ramkrishna Sarkar, Soumabrata Majumdar, Sierd Kuil, Jorg Mallens, Joost J. B. van Der Tol, Rint P. Sijbesma, Johan P. A. Heuts, Anja R. A. Palmans
Summary: Dynamic covalent networks (DCNs) utilize chemical bonds that can break and reform to allow for network reconfiguration under appropriate processing conditions. The addition of the acylsemicarbazide (ASC) motif, capable of hydrogen bonding and dynamic bond exchange, has expanded the repertoire of dynamic covalent bonds. This study demonstrates that the sulfur congener, thioacylsemicarbazide (TASC), also functions as a dynamic covalent bond, albeit with a slower exchange rate than ASC. DCNs based on siloxane incorporating ASC, TASC, or both, exhibit tunable relaxation dynamics that decrease with a higher proportion of TASC motifs. The reduction in stress relaxation is accompanied by a decrease in network creep, and can be controlled by adjusting the ASC/TASC ratio. These networks can be easily processed and dissolved using compression molding and excess hydrazide treatment, respectively. The ability to manipulate network properties and creep in dynamic covalent polymeric networks through minor modifications in dynamic bond structure provides a versatile synthetic approach that can be applied within a wide temperature range.
JOURNAL OF POLYMER SCIENCE
(2023)
Article
Polymer Science
Huiyi Zhang, Annemiek van Hertrooij, Tobias Schnitzer, Yinjun Chen, Soumabrata Majumdar, Rolf A. T. M. van Benthem, Rint P. Sijbesma, Johan P. A. Heuts
Summary: In dynamic polyamidenetworks, B4A units serve as a dynamic covalent cross-linker and supramolecular stacking motif simultaneously. The resulting materials have a higher rubbery plateau modulus compared to a reference network with suppressed supramolecular interactions. Branching polyamides with the same B4A dynamic motif form strong and reversible supramolecular networks through hydrogen bonding and stacking, while a nonstacking reference linker leads to a viscous liquid. Covalent cross-linking and stacking cooperatively contribute to the dynamics of the network, as confirmed by wide-angle X-ray scattering and variable-temperature infrared experiments.
Article
Polymer Science
Patrick Schara, Anna Maria Cristadoro, Rint P. Sijbesma, Zeljko Tomovic
Summary: Polyurethanes have a wide range of chemical and mechanical properties, and their recyclability can be greatly improved by introducing cleavable acetal bonds. This study presents a solvent-free synthesis of acetal-containing polyols using heterogeneous catalysts, and the obtained materials can be depolymerized under acidic and basic conditions with high recovery rates.
Article
Polymer Science
Yunfei Guo, Julian Kleemann, Stefan Bokern, Andre Kamm, Rint P. Sijbesma, Zeljko Tomovic
Summary: To meet the increasing demands on thermal and mechanical properties of PU materials, polyisocyanurates (PIRs) have been introduced in PU materials as crosslinkers. A liquid PIR prepolymer with high PIR content was prepared and further reacted with long chain polyols and chain extenders to obtain PIR elastomers that exhibited good thermal stability and improved mechanical properties. This work demonstrates the potential industrial applications of the liquid PIR prepolymer.
Article
Polymer Science
Yunfei Guo, Sebastian Spicher, Anna Cristadoro, Peter Deglmann, Rint P. Sijbesma, Zeljko Tomovic
Summary: Poly(urethane imide)s (PUIs) with improved thermal properties and flame retardancy can be directly synthesized by the reaction of isocyanates with anhydrides to give aromatic imides. Experimental studies and quantum chemical calculations have investigated the mechanism of this reaction in the presence of water. The computational study has provided insights into the underlying mechanism and guided the development of a solvent-free synthetic method for industrial-scale production of PUIs.
Article
Polymer Science
Jie Liu, Xianwen Lou, Maaike J. G. Schotman, Patricia P. Marin San Roman, Rint P. Sijbesma
Summary: This article describes the design of photo-responsive supramolecular hydrogels based on coumarin dimerization and de-dimerization. The researchers chemically incorporated the photo-responsive coumarin unit into an oligo(ethylene glycol) bis-urea amphiphile, which can co-assemble with non-functionalized OEG amphiphile to form supramolecular fibers. The mechanical strength of the hydrogels can be tuned using irradiation time, providing precise control of gelation.
