Article
Polymer Science
Yujin Cha, JiHyeon Hwang, Luis Ramos, Huina Lin, Tianyu Zhu, Chuanbing Tang
Summary: The synthesis of cyclic cobaltocenium and its application in the synthesis of high-performance copolymers have been reported.
Article
Chemistry, Multidisciplinary
Wensen Chen, Changjuan Guo, Hao Ding, Xingyu Yang, Ke Zhang
Summary: A novel controlled ring-opening polymerization method has been developed using a trimethyl lock unit as a ring-opening trigger, which enables the synthesis of polymers with controlled molecular weights and narrow dispersities. This versatile method can be applied to the synthesis of various polymers with different functionalities and structures.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Taeyang An, Hanseul Ryu, Tae-Lim Choi
Summary: This study presents a versatile approach to improve the alternation and degradability of 2,3-dihydrofuran (DHF) copolymers by carefully controlling the reactivity of both the Ru initiators and the monomers. The DHF copolymers showed outstanding A, B-alternation and could be broken down to a single repeat unit level under acidic conditions.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Phong K. Quach, Jesse H. Hsu, Ivan Keresztes, Brett P. Fors, Tristan H. Lambert
Summary: The ring-opening metathesis polymerization of cyclopropenes using hydrazonium initiators was investigated. The initiators, formed by condensing 2,3-diazabicyclo[2.2.2]octane and an aldehyde, polymerize cyclopropene monomers through a sequence of [3+2] cycloaddition and cycloreversion reactions. The study showed that the monomer to initiator ratio had a positive correlation with the degree of polymerization.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Polymer Science
Francis O. Boadi, Nicole S. Sampson
Summary: Bicyclo[4.2.0]oct-6-ene-7-carboxamide can form an alternating copolymer with cyclohexene in the presence of N-heterocyclic carbene-ruthenium catalyst. By creating a gradient copolymer with two different monomers, specific surface hydrophobicity, topology, and thermal properties can be controlled.
Article
Chemistry, Multidisciplinary
Antonio Rizzo, Eunsong Jung, Hojoon Song, Yunhyeong Cho, Gregory I. Peterson, Tae-Lim Choi
Summary: Cascade polymerization of unique polycyclic enyne monomers was explored, with modifications to monomer structure parameters allowing control over polymerization performance and efficiency. By analyzing degradation products under mild acidic conditions, the cascade efficiency could be calculated, leading to controlled living cascade polymerizations of multiple monomers with high efficiency.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Polymer Science
Yuxiang He, Ying Wu, Minghui Zhang, Yuanxing Zhang, Hao Ding, Ke Zhang
Summary: A novel controlled ring-opening polymerization (ROP) method based on the nucleophilic ring-opening mechanism was developed for the first time, utilizing a quinone methide elimination-based self-immolative spacer as the trigger. This method successfully synthesized backbone functional and sequence-defined polymers with controlled molecular weights and narrow dispersities.
Review
Chemistry, Applied
Nina Guy, Olivia Giani, Sebastien Blanquer, Julien Pinaud, Jean-Jacques Robin
Summary: Photopolymerization is gaining interest in both industrial and academic fields due to its high reaction kinetics, low emissions of organic solvents, and reduced shrinking stress. This method has mainly been developed for radical polymerization of vinyl monomers and to a lesser extent for ring-opening polymerization (ROP). With the emergence of new initiating systems, the photopolymerization of various cyclic monomers has expanded beyond epoxides, which were the first monomers polymerized by cationic ring-opening polymerization (CROP).
PROGRESS IN ORGANIC COATINGS
(2021)
Article
Chemistry, Multidisciplinary
Dmitry S. Belov, Logesh Mathivathanan, Melanie J. Beazley, William Blake Martin, Konstantin V. Bukhryakov
Summary: The study explores the capability of an iron-based catalyst in performing ring-opening metathesis polymerization of olefins, demonstrating that the use of in situ prepared heteroleptic iron catalysts significantly enhances polymerization rate and selectivity.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Review
Chemistry, Multidisciplinary
Alex J. Plajer, Charlotte K. Williams
Summary: Heteroatom-containing polymers have potential as sustainable replacements for petrochemicals, offering a wide range of properties for various applications. Catalysed ring-opening copolymerisation (ROCOP) provides a route to create precise new polymer structures, leading to a renaissance in research and commercial products.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Polymer Science
Jeffrey C. Foster, Joshua T. Damron, Honghai Zhang
Summary: Controlling the monomer sequence of synthetic polymers is a major challenge in polymer science. This study investigates cyclic olefin monomers for ring-opening metathesis polymerization (ROMP) and identifies easily synthesized oxanorbornene imide monomers suitable for single unit addition reactions. The findings enable the synthesis of multiblock copolymers with precise functionalization sites and singly cross-linked four-armed star copolymers.
Article
Polymer Science
Thomas R. Hoye, Mengyuan Jin
Summary: The purpose of this study was to develop a convenient 1H NMR method to estimate the propensity of lactones to participate in ring-opening transesterification polymerization (ROTEP). Methanolysis of 18 lactones was observed in CD3OD solution with sulfuric acid as a catalyst, and the ratio of remaining lactone to ring-opened methyl ester/alcohol could be measured through NMR spectroscopy. The thermodynamic driving force for the methanol ring openings correlated with the extent of ROTEP for different lactone classes, despite different reaction conditions. Qualitative evaluations of the rates of ring-opening methanolysis were also performed, revealing non-obvious relative reactivities. It is recommended to use this simple NMR methanolysis method for evaluating the polymerizability of new lactone monomers in the future.
Article
Materials Science, Composites
John M. Misasi, Buu N. Dao, Carmelo Dell 'Olio, Sam R. Swan, Salumeh Issadazeh, Jeffrey S. Wiggins, Russell J. Varley
Summary: This study investigates the synthesis and characterisation of macrocyclic oligomers (MCO) from 4, 4'-difluoro benzophenone and catechol, their ring opening polymerisation, fabrication into carbon fibre reinforced composite materials, and depolymerisation. The results provide important guidance on the future development of high performance thermoplastic composites through in-situ polymerisation, showcasing the reversible nature of the chemistry with MCO.
COMPOSITES SCIENCE AND TECHNOLOGY
(2021)
Article
Polymer Science
Mohammad Yasir, Andreas F. M. Kilbinger
Summary: Norbornene and cyclohexene show different polymerization behaviors using Grubbs' catalysts due to their varying ring strain energy levels; a sequence-selective cascade polymerization of a monomer containing both rings resulted in polymers with moderate molecular weight dispersities and good control over molecular weight.
Article
Biochemistry & Molecular Biology
Ervin Kovacs, Bence Balterer, Nguyen Anh Duc, Gyorgyi Szarka, Michael C. Owen, Attila Domjan, Bela Ivan
Summary: A large number of organic solvents contaminate the environment on a daily basis worldwide. This study demonstrates that benzotrifluoride can be used as a suitable solvent for olefin metathesis reactions, providing high yields and similar or even higher reaction rates compared to dichloromethane.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Article
Biochemistry & Molecular Biology
John E. Gadbery, James W. Round, Tianao Yuan, Matthew F. Wipperman, Keith T. Story, Adam M. Crowe, Israel Casabon, Jie Liu, Xinxin Yang, Lindsay D. Eltis, Nicole S. Sampson
Article
Polymer Science
Francis O. Boadi, Jingling Zhang, Xiaoxi Yu, Surita R. Bhatia, Nicole S. Sampson
Article
Chemistry, Medicinal
Amber C. Bonds, Tianao Yuan, Joshua M. Werman, Jungwon Jang, Rui Lu, Natasha M. Nesbitt, Miguel Garcia-Diaz, Nicole S. Sampson
ACS INFECTIOUS DISEASES
(2020)
Article
Biochemistry & Molecular Biology
Gyusaang Youn, Jakob Cervin, Xiaoxi Yu, Surita R. Bhatia, Ulf Yrlid, Nicole S. Sampson
Article
Chemistry, Medicinal
Tianao Yuan, Joshua M. Werman, Xingyu Yin, Meng Yang, Miguel Garcia-Diaz, Nicole S. Sampson
Summary: The study identified and characterized two genes involved in cholesterol catabolism in Mtb, shedding light on the unique metabolic pathway utilized by the bacterium. The protein products of these genes play crucial roles in the beta-oxidation of cholesterol, with distinct stereospecific hydration and dehydrogenation steps that differ from other species. The structural analysis of the enzymes reveals potential targets for therapeutic development against Mtb infection.
ACS INFECTIOUS DISEASES
(2021)
Article
Immunology
Thabatta L. S. A. Rosa, Maria Angela M. Marques, Zachary DeBoard, Kelly Hutchins, Carlos Adriano A. Silva, Christine R. Montague, Tianao Yuan, Julio J. Amaral, Georgia C. Atella, Patricia S. Rosa, Katherine A. Mattos, Brian C. VanderVen, Ramanuj Lahiri, Nicole S. Sampson, Patrick J. Brennan, John T. Belisle, Maria Cristina Pessolani, Marcia Berredo-Pinho
Summary: Upon infection, Mycobacterium leprae induces accumulation of cholesterol in Schwann cells, which is potentially delivered to the intracellular bacterium. Cholesterol oxidation is an essential catabolic pathway for M. leprae pathogenicity, with 3 beta-HSD as a potential drug target for leprosy treatment.
FRONTIERS IN CELLULAR AND INFECTION MICROBIOLOGY
(2021)
Article
Infectious Diseases
Xinxin Yang, Matthew F. Wipperman, Sharon Nachman, Nicole S. Sampson
Summary: Current TB diagnostic methods developed for adults are not suitable for children, especially those who are co-infected with HIV. This study established an ELISA assay to detect modified lipoprotein in plasma, which showed lower levels of TLP in active TB patients. This suggests that TLP has potential as a biomarker for TB detection in children.
BMC INFECTIOUS DISEASES
(2022)
Correction
Immunology
Thabatta L. S. A. Rosa, Maria Angela M. Marques, Zachary DeBoard, Kelly Hutchins, Carlos Adriano A. Silva, Christine R. Montague, Tianao Yuan, Julio J. Amaral, Georgia C. Atella, Patricia S. Rosa, Katherine A. Mattos, Brian C. VanderVen, Ramanuj Lahiri, Nicole S. Sampson, Patrick J. Brennan, John T. Belisle, Maria Cristina V. Pessolani, Marcia Berredo-Pinho
FRONTIERS IN CELLULAR AND INFECTION MICROBIOLOGY
(2021)
Article
Polymer Science
Xiaoxi Yu, Guofang Li, Bingqian Zheng, Gyusaang Youn, Ting Jiang, Suan P. Quah, Scott T. Laughlin, Nicole S. Sampson, Surita R. Bhatia
Summary: This study investigates the interfacial rheology of sequence-controlled copolymers and finds that an increase in microblock size enhances the interfacial storage modulus, thereby tuning surface and interfacial properties. The research indicates that microblock size can be utilized to control the interfacial rheology of amphiphilic copolymers, providing a new strategy for controlling the dynamics of fluid interfaces through precision sequence-controlled polymers.
MACROMOLECULAR CHEMISTRY AND PHYSICS
(2022)
Article
Chemistry, Multidisciplinary
Francis O. Boadi, Nicole S. Sampson
Summary: This study investigates the rates of ruthenium-catalyzed alternating ring opening metathesis (AROM) of cyclohexene using two different Ru-cyclohexylidenecarbenes derived from bicyclo[4.2.0]oct-6-ene-7-carboxamides with different side chains. The substitution of the amide directly affects the rate of ring opening of the bicyclo[4.2.0]oct-6-ene-7-carboxamide and the reaction rate of the resulting carbene with cyclohexene. Different factors, such as the stability of ligated complexes and the relative rates of ring opening reactions, are considered to determine the kinetics and gradient copolymer structures.
ACS ORGANIC & INORGANIC AU
(2023)
Article
Chemistry, Medicinal
Joshua M. Werman, Yu-Ching Chen, Tianao Yuan, Xinxin Yang, Nicole S. Sampson
Summary: By studying the effects of 6-azasteroid analogs on Mycobacterium tuberculosis and Mycobacterium marinum, we can enhance the antimycobacterial activity and gain a better understanding of the mechanism behind the potentiation of the antituberculosis drug bedaquiline.
ACS INFECTIOUS DISEASES
(2023)
Article
Polymer Science
Francis O. Boadi, Nicole S. Sampson
Summary: Bicyclo[4.2.0]oct-6-ene-7-carboxamide can form an alternating copolymer with cyclohexene in the presence of N-heterocyclic carbene-ruthenium catalyst. By creating a gradient copolymer with two different monomers, specific surface hydrophobicity, topology, and thermal properties can be controlled.
Article
Chemistry, Multidisciplinary
Gyusaang Youn, Nicole S. Sampson
Summary: This study reveals the unexpected reactivity of bicyclo[4.2.0] oct-6-ene substrates containing an alpha,ss-unsaturated amide moiety in ruthenium-catalyzed alternating ring-opening metathesis polymerization reactions. H-1 NMR and IR spectral analyses, as well as principal component analysis, are used to understand the reaction mechanism and identify key contributors to the fast ring-opening metathesis of the substrates.
ACS ORGANIC & INORGANIC AU
(2021)
Review
Biochemistry & Molecular Biology
Tianao Yuan, Joshua M. Werman, Nicole S. Sampson
Summary: Whole cell-based phenotypic screens have become the primary mode of hit generation in tuberculosis drug discovery over the past two decades, with different drug screening models developed to mimic the complexity of TB disease in the lab. Understanding the mechanism of action of TB drugs is essential for successful drug delivery due to the complex interactions between Mycobacterium tuberculosis and the drugs used for treatment.
RSC CHEMICAL BIOLOGY
(2021)
Article
Polymer Science
Jingling Zhang, Xiaoxi Yu, Bingqian Zheng, Jiachun Shen, Surita R. Bhatia, Nicole S. Sampson