Review
Chemistry, Organic
Ling-Yan Chen, Pei-Qiang Huang
Summary: Although asymmetric catalysis has advanced, the use of chiral auxiliaries remains crucial in asymmetric synthesis. Evans' method is widely used and has inspired the development of related methods. However, a comprehensive review on the extensions of Evans' chiral non-racemic oxazolidinone-based asymmetric methodology is still elusive. This review summarizes the extensions of the Evans asymmetric methodology, covering various aspects such as auxiliary modification, aldol reaction extension, and asymmetric reaction type extension. Asymmetric methodology remains an indispensable tool for accessing enantiomeric natural products and medicinal agents.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Review
Chemistry, Organic
Zi-Lu Wang, Yun-He Xu
Summary: The synthesis of chiral compounds has always been a major focus of organic chemists. In recent years, axially chiral compounds have gained considerable attention due to their widespread utility in asymmetric catalysis and synthesis. However, compared to chiral allenes and chiral biaryl compounds, there are fewer methods available for the asymmetric synthesis of axially chiral cycloalkylidenes.
SYNTHESIS-STUTTGART
(2023)
Article
Chemistry, Inorganic & Nuclear
Dominik Baran, Sergei I. Ivlev, Eric Meggers
Summary: In this work, an auxiliary-mediated deracemization protocol was introduced for the synthesis of a non-C-2-symmetric chiral-at-ruthenium catalyst, which was then applied to an enantioselective ring-closing reaction.
Article
Chemistry, Multidisciplinary
Stuart C. D. Kennington, Saul F. Teloxa, Miguel Mellado-Hidalgo, Oriol Galeote, Sabrina Puddu, Marina Bellido, Pedro Romea, Felix Urpi, Gabriel Aullon, Merce Font-Bardia
Summary: A direct and asymmetric aldol reaction of N-acyl thiazinanethiones with aromatic aldehydes catalyzed by chiral nickel(II) complexes was reported. The reaction gives high yields of O-TIPS-protected anti-aldol adducts with remarkable stereocontrol and atom economy. The removal of the achiral scaffold provides enantiomerically pure intermediates with synthetic interest for producing anti-alpha-amino-beta-hydroxy and alpha,beta-dihydroxy carboxylic derivatives, with theoretical calculations explaining the observed high stereocontrol.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Yuki Saito, Shu Kobayashi
Summary: The application of heterogeneous catalysts in continuous-flow enantioselective hydroacylation reactions was studied. Catalysts were prepared by mixing supports and rhodium complexes, and showed excellent activity and enantioselectivity. Under optimized conditions, the catalysts exhibited high turnover numbers and could be applied to various substrates. Furthermore, sequential-flow reactions with other heterogeneous catalysts were demonstrated for the synthesis of biologically active molecules and functional materials.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Azusa Togo, Shiori Suzuki, Satoshi Kimura, Tadahisa Iwata
Summary: The mechanical properties of regenerated alpha-1,3-glucan fiber were improved by transforming the crystal structure and stretching methods, resulting in comparable tensile strength with viscose rayon. Two different crystal polymorphs, polymorph II and polymorph III, were identified in the regenerated fibers depending on post-treatment methods. Additionally, the study revealed that polymorph III is identical to polymorph IV based on distinctive 2D-WAXD patterns.
Article
Chemistry, Organic
Alberto Marban-Gonzalez, Gaspar Maravilla-Moreno, Josue Vazquez-Chavez, Marcos Hernandez-Rodriguez, Rodrigo Said Razo-Hernandez, Mario Ordonez, Jose Luis Viveros-Ceballos
Summary: A versatile intermediate for further stereocontrolled transformations to access enantiopure cis-fused octahydroisoindolones was synthesized through kinetically controlled cyclocondensation of stereoisomeric and ring-chain tautomeric mixture of (+/-)-hydroxylactone 1 and 0.5 equiv of (R)-phenylglycinol. An extension of this methodology was successfully applied to the synthesis of the 5,6-dihydroxy derivative.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Bo-Bo Gou, Yue Tang, Yan-Hong Lin, Le Yu, Qing-Song Jian, Huai-Ri Sun, Jie Chen, Ling Zhou
Summary: A new type of chiral all-carbon tetrasubstituted VQMs was successfully prepared via nucleophilic addition of 2-alkynylnaphthols to o-quinone methides or imines, catalyzed by chiral phosphoric acids. The method showed high efficiency and excellent diastereoselectivities and enantioselectivities, leading to the synthesis of naphthyl-2H-chromenes with axially and centrally chiral elements and axially chiral quinone-naphthols. The obtained axially chiral naphthols could further be converted into valuable phosphine ligands and other functional molecules.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Review
Biochemistry & Molecular Biology
Cuong Viet Bui, Thomas Rosenau, Hubert Hettegger
Summary: The review summarizes recent developments in chiral selectors, CSP preparation, chiral recognition mechanisms, and enantiomeric separation methods based on polysaccharides and beta-cyclodextrins as chiral selectors, focusing on the years 2019-2020 in this rapidly evolving field.
Article
Polymer Science
Marwa Faisal, Tingting Kou, Yuyue Zhong, Andreas Blennow
Summary: As biodegradable and eco-friendly bio-resources, polysaccharides from a wide range of sources are gaining increasing interest. High amylose starch (HAS) has made significant progress in the market due to its unique properties and improved nutritional values, and HAS variants of other crops are also expected to be commercially available soon. This review focuses on the various forms and processing techniques of HAS-based polymers and composites, as well as the development of low toxic and high compatibility natural plasticizers. The review also highlights the importance of mechanical and barrier properties for HAS-based materials, and discusses opportunities for HAS-based food and biomedical fabrications.
Article
Chemistry, Organic
Tao Zhang, Wen-Ao Li, Hong-Cheng Shen, Shu-Sen Chen, Zhi-Yong Han
Summary: An asymmetric Heck-Matsuda reaction targeting acyclic internal alkenes was successfully developed through the strategy of chiral anion phase transfer, resulting in high levels of enantioselectivity in the formation of chiral ketones. The use of a catalytic amount of dimethyl sulfoxide (DMSO) as an additive is crucial for suppressing palladium-hydride-mediated side reactions.
Review
Multidisciplinary Sciences
Anastasy O. Kolodiazhna, Oleg Kolodiazhnyi
Summary: This review focuses on the development of methods for catalytic asymmetric synthesis of phosphonates with chiral centers in the side chain. These methods have practical applications in synthesizing phosphonates with diverse biological activities found in natural compounds.
Article
Chemistry, Applied
Fan Wang, Weiqi Wang, Yuqing Wang, Wei Zheng, Ting Zheng, Lili Zhang, Yoshio Okamoto, Jun Shen
Summary: Three novel amylose and cellulose phenylcarbamate derivatives were synthesized as chiral fluorescent sensors, showing good enantioselective properties. These derivatives demonstrated high efficiency in chiral fluorescent sensing for important chiral drug intermediates and also displayed good resolution powers as chiral stationary phases in high-performance liquid chromatography. The excitation-dependent chiral fluorescent sensing mechanism was found to be different from chromatographic enantioseparation.
CARBOHYDRATE POLYMERS
(2023)
Article
Multidisciplinary Sciences
Monica Fiorenza Boselli, Chiara Faverio, Elisabetta Massolo, Laura Raimondi, Alessandra Puglisi, Maurizio Benaglia
Summary: The development of new methods for introducing fluorine atoms or fluorinated moieties in molecular scaffolds is crucial in organic synthesis. The incorporation of the SCF3 group into organic molecules has shown beneficial effects on drug stability and bioavailability. By using a chiral auxiliary, enantioenriched alpha-SCF3-tetrasubstitued beta-keto esters can be synthesized in good yields with high enantioselectivity.
Article
Chemistry, Multidisciplinary
Jialin Qi, Fang Wei, Shuai Huang, Chen-Ho Tung, Zhenghu Xu
Summary: A new method has been developed for the synthesis of sulfur-containing chiral beta-lactams with two consecutive stereogenic centers using copper(I)-catalyzed asymmetric, three-component interrupted Kinugasa reaction. The key lies in the interception of in situ formed chiral four membered copper(I) enolate intermediate with sulfur electrophiles, resulting in good yields and excellent diastereo- and enantioselectivity.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Applied
Xiaodan Wu, Zihan Wang, Guansong Shao, Bingyang Qin, Ying Wang, Tao Wang, Zhiguo Liu, Yujie Fu
Summary: In this study, a new type of cellulose-based ionic imprinting adsorbent was developed for the selective removal of cobalt ions. The adsorbent exhibited excellent adsorption performance, high cycling stability, and preferential selectivity for cobalt ions. The simple preparation method and promising application prospects make it a promising candidate for water treatment.
REACTIVE & FUNCTIONAL POLYMERS
(2024)
Article
Chemistry, Applied
Chandirasekar Shanmugam, Vanitha Marimuthu, Nagappan Rajendiran
Summary: In this study, monodispersed gold and silver nanoparticles were synthesized using cholic acid functionalized star poly(DL-lactide) as a capping and reducing agent. The synthesized materials were found to be effective heterogeneous catalysts for the reduction reaction.
REACTIVE & FUNCTIONAL POLYMERS
(2024)
Article
Chemistry, Applied
Bianca-Iulia Ciubotaru, Mirela-Fernanda Zaltariov, Mihaela Dascalu, Adrian Bele, Alexandra Bargan, Maria Cazacu
Summary: Porous networks were obtained using polysiloxanes pendant functionalized with aminopropyl groups. The addition of certain substances, such as ammonium bicarbonate and acetic acid, promoted the porosity and covalent cross-linking of the polymer. The resulting materials exhibited high dielectric permittivity and significant electrical output signal when subjected to compression, making them suitable for capacitive pressure sensors.
REACTIVE & FUNCTIONAL POLYMERS
(2024)
Article
Chemistry, Applied
Mohamed A. Zein, Basim H. Asghar, Abdulaziz M. Almohyawi, Norah F. Alqahtani, Ahmed Alharbi, J. Alkabli, Reda F. M. Elshaarawy, Lamia A. Ismail
Summary: In this study, new amphiphilic chitosan-thyme extract-nanosilver nanocomposites were prepared, which synergistically inhibited bacterial biofilm formation and bacterial proliferation. The nanocomposites disrupted bacterial cell membranes, causing cell death, and prevented biofilm formation. In addition, the nanocomposites exhibited good biocompatibility, making them potential candidates for biomedical applications.
REACTIVE & FUNCTIONAL POLYMERS
(2024)
Review
Chemistry, Applied
Norah F. Alqahtani
Summary: This review explores the potential of Imidazolium-based ionic liquids (ImILs) in improving the solubility, stability, and functionality of chitosan, and provides an overview of the types and preparation methods of functionalized imidazolium ionic liquids (FImILs). Additionally, it discusses the various opportunities offered by FImIL-chitosan derivatives.
REACTIVE & FUNCTIONAL POLYMERS
(2024)
Article
Chemistry, Applied
Olesya N. Zabegaeva, Alexey F. Kosolapov, Sergei L. Semjonov, Mariam G. Ezernitskaya, Egor S. Afanasyev, Ivan A. Godovikov, Alexander Chuchalov, Dmitriy A. Sapozhnikov
Summary: Polyimides are commonly used as primary protective coatings for optical fibers in high-temperature applications. However, the manufacturing process is complicated due to certain drawbacks. This study shows the potential use of polyamide-imides as highly reliable protective coatings for optical fibers.
REACTIVE & FUNCTIONAL POLYMERS
(2024)
Article
Chemistry, Applied
Luis Miguel Nunez Tapia, Pascal Thebault, Laurent Bischoff, Alain Ledoux, Florian Defontaine, Olivier Lesouhaitier, Fabrice Burel
Summary: A water soluble cationic bis-cyclocarbonate was prepared through a three steps procedure, and non-isocyanate polyurethanes were prepared in acetonitrile with high yields. The resulting materials exhibited good thermal properties and hydrophilic properties. The polyurethane thermoset showed high inhibition towards bacteria, and the bis-cyclocarbonate oligomer was found to be harmless to organisms.
REACTIVE & FUNCTIONAL POLYMERS
(2024)