Article
Chemistry, Multidisciplinary
Gaorong Wu, Xiaobo Xu, Shuai Wang, Lu Chen, Binghan Pang, Tao Ma, Yafei Ji
Summary: This study reports a novel metal-free method for C-H borylation of 2-(N-methylanilino)-5-fluoropyridines and 2-benzyl-5-fluoropyridines. The reaction exhibited high efficiency and site exclusivity, allowing for gram-scale synthesis of borylated products with good derivatization applications. Furthermore, the directing group could be easily removed.
CHINESE CHEMICAL LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Xuejiao Tang, Kun Liu, Zeming Qu, Junyan Zhan, Rukui Zhu, Fan Teng, Lili Meng, Yanmin Huang, Chusheng Huang, Yimiao He, Qiang Zhu
Summary: A [3 + 2]/[2 + 1] cycloaddition reaction of gem-difluorocyclopropenes has been developed for accessing tri- and tetra-substituted 4-fluoropyridines in a mild and efficient manner. The reaction shows excellent regioselectivity and moderate to good yields. Various synthetic applications, including process-scale reactions and modification of bioactive molecules, are described.
CHINESE CHEMICAL LETTERS
(2022)
Article
Multidisciplinary Sciences
Surasa Nagachinta, Paolo Novelli, Yoann Joyard, Nicolas Maindron, Patrick Riss, Sylvestre Dammicco
Summary: This paper describes an efficient one-step labeling procedure for synthesizing N-succinimidyl-4-[F-18]fluorobenzoate ([F-18]SFB) using a tin precursor. This method avoids volatile radioactive byproducts and simplifies the automation process. Through HPLC purification, [F-18]SFB with a radiochemical purity of more than 99% was obtained.
SCIENTIFIC REPORTS
(2022)
Article
Chemistry, Organic
James W. McDaniel, Julia M. Stauber, Evan A. Doud, Alexander M. Spokoyny, Jennifer M. Murphy
Summary: This study reports a method for labeling unprotected peptides and sugars with a Au(III)-[F-18]fluoroaryl complex, which can generate F-18-labeled S-aryl bioconjugates in an aqueous environment in 15 minutes with high yields and excellent functional group tolerance. The method utilizes a stable organometallic Au(III) complex and highlights the versatility of designer organometallic reagents as efficient agents for rapid radiolabeling.
Article
Chemistry, Multidisciplinary
Gargi Kundu, V. S. Ajithkumar, Milan Kumar Bisai, Srinu Tothadi, Tamal Das, Kumar Vanka, Sakya S. Sen
Summary: The reaction between IDipp and C5F5N can functionalize all three carbon atoms of the imidazole ring, while the reaction of SIDipp with C5F5N in the presence of BF3 leads to ring cleavage. Furthermore, analogous reactions with silylene result in oxidative addition at the Si(II) center.
CHEMICAL COMMUNICATIONS
(2021)
Article
Chemistry, Physical
Wei Hao, Candice L. Joe, Sloan Ayers, Andrea Daru, Ryan A. Daley, Michal Domanski, Jason S. Chen, Michael A. Schmidt, Donna G. Blackmond
Summary: This study reported a highly efficient and enantioselective asymmetric hydrogenation catalyzed by Ru-DTBM-segphos for a broad range of pyridine-pyrroline trisubstituted alkenes, revealing the reaction mechanism through kinetic, spectroscopic, and computational studies, as well as an intriguing Ru-catalyzed H/D exchange process.
Article
Chemistry, Physical
Wei Hao, Candice L. Joe, Sloan Ayers, Andrea Daru, Ryan A. Daley, Michal Domanski, Jason S. Chen, Michael A. Schmidt, Donna G. Blackmond
Summary: A highly efficient and enantioselective Ru-DTBM-segphos catalyzed asymmetric hydrogenation of pyridine-pyrroline trisubstituted alkenes is reported. Kinetic, spectroscopic, and computational studies suggest that the rate-determining step is the addition of H2, alkene insertion determines the enantioselectivity, and the presence and position of the pyridine nitrogen are critical for enantioselectivity. These studies also reveal a Ru-catalyzed H/D exchange process facilitated by the substrate at room temperature and low pressure, where hydrogenation activity is suppressed. A mechanistic proposal is provided to further define the roles of hydrogen gas, Ru-H species, and protic solvents in this catalytic system.
Article
Chemistry, Multidisciplinary
Daniel Hernandez-Valdes, Saman Sadeghi
Summary: The development of F-18-based radiopharmaceuticals requires innovative fluorination methods, where [F-18]fluoride is the preferred isotope form. Challenges arise in the late-stage use of [F-18]fluoride, leading to a growing interest in electrochemical fluorination as an alternative approach.
Article
Polymer Science
Nicholas J. Bongiardina, Katelyn F. Long, Maciej Podgorski, Christopher N. Bowman
Summary: The thiol-thioester reaction is a promising method for developing covalent adaptable networks (CANs) due to its rapid exchange under low temperature conditions, orthogonality in various solvents, and tunability. Study on the effects of thiol substitution in two dynamic thioester reactions revealed that mixtures of primary thiols and secondary thioesters have K-eq near unity, with a slight bias towards primary thioesters in nonpolar solvents. Dynamic experiments showed that secondary thioester-based networks exhibit slower dynamics compared to primary networks by at least one order of magnitude.
Article
Chemistry, Inorganic & Nuclear
Mucahit ozdemir, Baybars Koksoy, Halid Kuruca, Ahmet Altindal, Mahmut Durmus, Sermet Koyuncu, Bahattin Yalcin, Mustafa Bulut
Summary: A series of new metallophthalocyanines with ferrocene groups were synthesized and investigated for their photovoltaic properties as electron-donor materials in BHJ solar cells. Characterization was done using various spectroscopic methods, electrochemical techniques, and density functional theory calculations. The results showed a red-shift in UV-Vis measurements for one of the complexes, and the highest photovoltaic conversion efficiency was achieved by devices based on compound 5.
DALTON TRANSACTIONS
(2022)
Article
Chemistry, Organic
Jianbo Zhao, Mengzi Chen, Min Wu, Lei Shi, Hao Li
Summary: An efficient and convenient strategy has been developed for the synthesis of pentasubstituted meta-fluoropyridines, using N-methyl-2,2,6,6-tetramethylpiperidine (PMP) as a catalyst to promote the annulation-aromatization cascade reaction between trifluoromethyl ketimines and maleimides. Two C-F bond cleavages occur in both the [4+2] cycloaddition and aromatization steps. The resulting pentasubstituted meta-fluoropyridines can be reduced to tertiary amines using BH3 in moderate yield.
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Biochemistry & Molecular Biology
Xiang Zhang, Falguni Basuli, Sameh Abdelwahed, Tadhg Begley, Rolf Swenson
Summary: A simple and efficient process for fluorine-18-labeled 1,2,3-triazole was reported, achieving successful radiofluorination through iodine-fluorine-18 exchange in an aqueous medium. The methodology was optimized on a model reaction and validated on multiple 1,2,3-triazole substrates, with radiochemical conversions ranging from 18-60%. Using this strategy, a triazole-based thiamin analogue was synthesized with isolated radiochemical yield of 10-16% in 40 minutes, showing potential for positron emission tomography (PET) imaging of thiamin-dependent enzymes.
Article
Chemistry, Physical
Shehani T. Wetthasinghe, Chunyan Li, Huina Lin, Tianyu Zhu, Chuanbing Tang, Vitaly Rassolov, Qi Wang, Sophya Garashchuk
Summary: Metallocenium cations, used in an anion exchange membrane of a fuel cell, show great thermal and alkaline stability, which can be enhanced by modifying the substituent groups on the cyclopentadienyl rings. This study establishes a relationship between the bond dissociation energy (BDE) of cobaltocenium derivatives and chemistry-informed descriptors obtained from electronic structural calculations.
JOURNAL OF PHYSICAL CHEMISTRY A
(2022)
Article
Chemistry, Physical
Athanassios C. Tsipis, Constantinos A. Tsipis
Summary: This study investigates the anomeric and Perlin effects in 2-substituted-2-fluorotetrahydro-2H-pyrans using sensitive structural, energetic, and NMR probes. Different substituents display preferences for axial or equatorial conformations, with some inducing normal Perlin effects and others the reverse. The research demonstrates a general relationship and shared stereoelectronic origin between the Perlin and anomeric effects.
JOURNAL OF PHYSICAL CHEMISTRY A
(2021)
Article
Chemistry, Physical
Chunyan Li, Shehani T. Wetthasinghe, Huina Lin, Tianyu Zhu, Chuanbing Tang, Vitaly Rassolov, Qi Wang, Sophya Garashchuk
Summary: An efficient modeling approach is presented to assess the chemical stability of cationic cobaltocenium derivatives using machine learning techniques. The stability of the complexes is found to strongly correlate with the energies of the highest occupied and lowest unoccupied molecular orbitals. Neural network models are developed to predict the bond dissociation energies with high accuracy. The results demonstrate the potential of machine learning techniques in predicting complex relationships with small data sets.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2022)
