Article
Chemistry, Multidisciplinary
Anna Pees, Maria J. W. D. Vosjan, Neil Vasdev, Albert D. Windhorst, Danielle J. Vugts
Summary: This article describes the first synthesis and application of fluorine-18 labelled Ruppert-Prakash reagent [F-18]Me3SiCF3, which was used to successfully prepare F-18-trifluoromethylated compounds by reacting with benzaldehydes, acetophenones and benzophenones.
CHEMICAL COMMUNICATIONS
(2021)
Article
Chemistry, Multidisciplinary
Alexey L. Trifonov, Alexander D. Dilman
Summary: A metal-free one-pot process for the gem-difluoroolefination of amides is presented, where the reaction involves the interaction between in situ generated alpha-chloroiminium salts and difluorinated phosphorus ylide formed from difluorocarbene and triphenylphosphine. The olefination proceeds via nucleophile-assisted dephosphorylation and takes place within one hour at low temperature. The gem-difluoroenamines obtained can be further transformed into a variety of fluoroalkylated amines.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Organic
Yanyao Cai, Wenjie Zhu, Shujuan Zhao, Chanjuan Dong, Zhenchuang Xu, Yanchuan Zhao
Summary: A difluorocarbene-mediated cascade cyclization reaction has been developed for rapid synthesis of gem-difluorinated 3-coumaranone derivatives, showing its potential application in the late-stage modification of diethylstilbestrol. Mechanistic studies revealed the multiple crucial roles played by the Ruppert-Prakash reagent.
Article
Chemistry, Organic
Junya Yukiyasu, Ryoto Inaba, Takashi Yumura, Hiroaki Imoto, Kensuke Naka
Summary: The catalytic Wittig reaction is commonly used for generating alkenes without the production of phosphine oxide in stoichiometric amounts. The catalytic arsa-Wittig reaction, which utilizes arsine catalysts instead of phosphine, provides excellent E-selectivity but requires high temperatures due to the low nucleophilicity of arsines. In this study, cyclic and acyclic arsines were prepared and examined for their catalytic activities, with tris(p-(dimethylamino)phenyl)arsine (5) showing high catalytic activity despite being an acyclic arsine. The optimized conditions allowed for the room-temperature arsa-Wittig reaction to proceed with high yield and E-selectivity, with density functional theory calculations helping to elucidate the reaction mechanism when using compound 5 as a catalyst.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Chemistry, Organic
Denys A. Kvasha, Andrii Deviatkin, Andrii S. Poturai, Pavel S. Nosik, Andrii A. Kyrylchuk, Sergiy Suikov, Alexander B. Rozhenko, Dmitriy M. Volochnyuk, Oleksandr O. Grygorenko
Summary: Imidazoles reacted with trimethyl(trifluoromethyl)silane-tetrabutylammonium difluorotriphenylsilicate (CF3SiMe3-TBAT) to undergo C-difluoromethylation at the C-2 position, with the intermediates 2-(trimethylsilyl)difluoromethyl-substituted derivatives eventually converting to 2-difluoromethyl-substituted imidazoles. Quantum chemical calculations propose two possible reaction mechanisms, both involving intermediate imidazolide anions stabilized by solvent molecules and counterions. These mechanisms proceed without high activation barriers.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Vitalij V. Levin, Alexander D. Dilman
Summary: A new synthesis method of alpha-trifluoromethylstyrenes from aromatic ketones and (trifluoromethyl)trimethylsilane is described, which involves nucleophilic trifluoromethylation and elimination of trimethylsilanol within one reaction flask. This innovative method streamlines the process of synthesizing alpha-trifluoromethylstyrenes by combining two important reactions in a single step.
MENDELEEV COMMUNICATIONS
(2021)
Article
Chemistry, Multidisciplinary
Simon Trzmiel, Jan Langmann, Daniel Werner, Caecilia Maichle-Moessmer, Wolfgang Scherer, Reiner Anwander
Summary: The reaction of CHI3 with six equivalents of CrCl2 at low temperatures resulted in the first isolable high-yield Cr-III mu(3)-methylidyne complex. Substitution of terminal chlorido ligands with alkali-metal cyclopentadienides produced isostructural half-sandwich chromium(III)-mu(3)-methylidynes. Side and decomposition products of the Cl/Cp(R) exchange reactions were identified and characterized.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Mixiang Tian, Lidong Shao, Xiaosan Su, Xuhong Zhou, Honglei Zhang, Kun Wei, Ruifen Sun, Junliang Wang
Summary: A new method has been developed for selective oxygenation of benzaldehydes and benzylic amines at the ortho positions to prepare fluoroalkyl aryl ethers.
Article
Chemistry, Organic
Chuyuan Lin, Lu Chen, Huaping Lin, Yibiao Li, Chengshuo Shen, Min Zhang
Summary: In this study, we present a new and practical approach for synthesizing aryl α,α-chlorofluoro arylketones directly in aqueous trifluoroethanol using a compatible system of selectfluor and NaCl. The method is metal-free and utilizes readily available feedstocks, demonstrating good tolerance towards functional groups. This work provides a raw material basis for the further preparation of fluorinated organic molecules.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Review
Chemistry, Multidisciplinary
Arturs Sperga, Janis Veliks
Summary: This review discusses the synthesis methods of monofluorinated compounds and their applications in the synthesis of organofluorine compounds. The use of monofluorinated carbenes and related reactive species allows for the formation of C-C or C-X bonds while introducing valuable fluorine atoms into the target structure.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Multidisciplinary Sciences
Muhammad Awais Ashraf, Yunjeong Lee, Naila Iqbal, Naeem Iqbal, Eun Jin Cho
Summary: Trifluoromethylated molecules have gained privileged recognition among medicinal and pharmaceutical chemists. Sustainable photoredox- and electrochemical processes were employed to access trifluoromethyl- and allyl-substituted tert-alcohols through radical cross-electrophile coupling, providing valuable tertiary alcohols with trifluoromethyl and allyl groups. The transformations are mild and chemo-selective, with potential applications in the synthesis of amine variants as amide bioisosteres.
Article
Chemistry, Organic
Min Zeng, Fuli Huang, Minghui Zhu, Jichao Ding, Tong Qin, Maoting Xu, Wanqing Liu, Jun Lu, Jicheng Wu, Xurong Qin, Qiao Ren
Summary: Despite the availability of chemical feedstocks, developing useful cross-coupling reactions with methyl esters as acyl electrophiles is still challenging due to their chemical inertness. We present a simple nickel-catalyzed intramolecular alkene hydroacylation method for the efficient synthesis of various medicinally active indanone and indazolone derivatives. This approach offers good functional group tolerance, easy post-synthetic modifications, total synthesis, and fluorescent probe synthesis. Preliminary in vitro antioxidant evaluation reveals promising free radical scavenging activities of 2-(4-dimethylaminophenyl)-1-indanone and 2-aryl-3-indazolone derivatives.
ORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Organic
Tommy Lussier, Claude Y. Legaul
Summary: Using readily available chiral HVI reagents, enantioenriched gamma-butyrolactones can be prepared with generally high enantioselectivities and modest to high yields. The resulting chiral iodoarene can be easily recovered and reused for multiple reactions without loss of yield or enantioselectivities.
Article
Chemistry, Multidisciplinary
Jiaming Peng, Cangsong Liao, Carsten Bauer, Florian P. Seebeck
Summary: Strategically replacing protons with fluorine atoms or functional groups has proven to be an effective way to optimize the activity of therapeutic compounds, leading to intense development in the field of organofluorides. However, literature on fluorine biocatalysis is still limited, with the introduction of SAM-dependent methyltransferases as a new tool for producing fluorinated compounds being a key innovation in the field. This approach demonstrates the ability of halide methyltransferases to form unstable fluorinated SAM, accepted as a substrate by specific methyltransferases for enzyme-catalyzed fluoromethylation of small molecules.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Organic
Jia Wang, Xiao-Xiao Lu, Run-Ping Yang, Bing-Bing Zhang, Zhi-Hao Xiang, Jia-Cheng Li, Lixia Liu, Shujun Chao, Xuefang Shang
Summary: A new electrophilic trifluoromethylselenolation reagent, Phth-SeCF3, has been developed for the synthesis of 4-trifluoromethylselenolated isoxazoles through electrophilic trifluoromethylselenolation cyclization. This protocol has the advantages of broad substrate scope, good functional group tolerance, and high yields.
Article
Biochemical Research Methods
Deepti Katiyar, Rashmi Saxena, Abhishek Kumar, Surya Prakash, Abhay Bhardwaj, Priya Bansal
Summary: This article presents a literature metasynthesis on Bryonia laciniosa, highlighting its phytochemical and therapeutic profile. The plant exhibits a range of pharmacological activities including antimicrobial, anti-inflammatory, analgesic, antipyretic, anticonvulsant, anti-asthmatic, anticancer, antioxidant, antidiabetic, and aphrodisiac effects.
COMBINATORIAL CHEMISTRY & HIGH THROUGHPUT SCREENING
(2023)
Article
Geosciences, Multidisciplinary
K. A. Kamesh Raju, V. Yatheesh, A. Srinivas Rao, L. Surya Prakash, Durbar Ray, Abhay Mudholkar, Kiranmai Samudrala, Nico Augustin, P. John Kurian
Summary: The topographic fabric of the rift valley floor in a segment of the slow-spreading Central Indian Ridge was analyzed using data obtained by the autonomous underwater vehicle (AUV) Abyss. The AUV dives revealed features such as a lava lake, a cratered volcano, an oceanic core complex (OCC), and a foot wall volcanic complex. The analysis of CTD data indicated the presence of temperature spikes related to leaky venting of fluids from a linear fissure on the seafloor.
GEO-MARINE LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Christopher J. J. Koch, Anushan Alagaratnam, Alain Goeppert, G. K. Surya Prakash
Summary: Cellulose, a major component of plant matter, is a potential target for biomass conversion to fuels. Direct conversion of cellulose to methane using nickel-based catalysts often faces challenges due to carbon agglomeration. The addition of rare-earth metals as promoters increases cellulose conversion to methane, but leads to catalyst deactivation in the form of nickel-rare-earth-carbon nanoparticles. Adding zinc metal as an additional promoter eliminates carbon agglomeration and improves methane yields. This study reports an 81% methane yield from cellulose within 48 hours using a Ni/Zn/Y/Al2O3 catalyst, at 225 degrees C and under 50 bar H-2 pressure.
ISRAEL JOURNAL OF CHEMISTRY
(2023)
Article
Chemistry, Organic
Xanath Ispizua-Rodriguez, Vinayak Krishnamurti, Vanessa Carpio, Colby Barrett, G. K. Surya Prakash
Summary: An efficient method for direct difluoromethylation of terminal alkynes and desilylation-difluoromethylation of (trimethylsilyl)acetylenes is reported. Copper-catalyzed transformation using a (difluoromethyl)zinc reagent and an organic oxidant provides access to a variety of structurally diverse CF2H alkynes in good yields. The synthetic utility of these (difluoromethyl)alkynes is demonstrated by selected cycloaddition reactions, and a slight modification to the reaction conditions allows the selective preparation of a 2-difluoromethylindole.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Geochemistry & Geophysics
P. Linsy, L. Surya Prakash, Parijat Roy, Muhammad Shuhail, P. John Kurian
Summary: This study conducted a detailed investigation on the geochemical characteristics of iron using a sediment core from the eastern Southwest Indian Ridge. The results revealed that a significant amount of hydrothermal iron precipitates near the source and plays a crucial role in oceanic elemental cycling.
Article
Chemistry, Multidisciplinary
Daniel Lin, Juan Pablo de los Rios, G. K. Surya Prakash
Summary: N-(difluoromethyl)amino (-NCF2H) compounds have unique and underexplored physiochemical properties, but lack structural diversity due to a shortage of efficient installation protocols. This study presents a new shelf-stable pyridinium reagent that enables direct installation of the N-(difluoromethyl)sulfonamide moiety onto (hetero)arenes and alkenes, diversifying the aryl and alkyl NCF2H compounds. The protocol utilizes blue light photoredox catalysis, demonstrating broad functional group tolerance and excellent chemoselectivity. Additional transformations and applicability towards a photoredox continuous flow protocol are also shown.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Review
Chemistry, Multidisciplinary
Daniel Lin, Matthew Coe, Vinayak Krishnamurti, Xanath Ispizua-Rodriguez, G. K. Surya Prakash
Summary: In recent years, many reagents and protocols have been developed for efficient fluorofunctionalization of various scaffolds. Organofluorine chemistry and visible light-mediated synthesis have played complementary roles in expanding the fields and discovering new bioactive compounds. This review focuses on the recent advances made in visible light-mediated fluoroalkylation and heteroatom centered radical generation.
Article
Engineering, Electrical & Electronic
Vivek Singh Baghel, Surya Prakash
Summary: Biometric authentication systems are widely used for securing various applications, including consumer electronics devices. However, the increased use of biometric authentication poses the risk of permanently compromising a person's biometric identity, as biometric data cannot be changed. This paper proposes a secure and non-invertible fingerprint based user template protection technique, which utilizes 3D-grid mapping and Discrete Fourier Transform. The technique is evaluated using publicly available fingerprint databases and demonstrates superior results compared to state-of-the-art techniques.
IEEE TRANSACTIONS ON CONSUMER ELECTRONICS
(2023)
Article
Chemistry, Inorganic & Nuclear
Alexander Knieb, Vinayak Krishnamurti, Ziyue Zhu, G. K. Surya Prakash
Summary: A metal-free protocol for the synthesis of monofluoromethylarenes using diaryliodonium salts and fluorobis (phenylsulfonyl)methane (FBSM) is presented as an alternative to traditional metal-mediated monofluoromethylation reactions. Inexpensive and accessible starting materials are utilized, and the target products are obtained with excellent yields (up to 97%) and good functional group tolerance. The counter anion of the iodonium species is found to significantly affect the reaction yield, and the ionic nature of the reaction mechanism is elucidated using Hammett's linear free energy analysis, supported by control experiments.
JOURNAL OF FLUORINE CHEMISTRY
(2023)
Article
Chemistry, Physical
Christopher J. Koch, Zohaib Suhail, Alain Goeppert, G. K. Surya Prakash
Summary: Rising CO2 levels enhance the greenhouse gas effect in the atmosphere, but CO2 can be captured and converted to methane using hydroxide salts and catalysts.
Article
Oceanography
P. Linsy, Tyson Sebastian, L. Surya Prakash, Parijat Roy, John Kurian Palayil
Summary: Mineral magnetic and geochemical investigations on a sediment core from the eastern Southwest Indian Ridge revealed variations in source components. The top-bottom variability indicated an increased contribution of hydrothermal components in the upper section of the core. Thermomagnetic measurements identified magnetite as the major remanence carrier, along with minor contributions from titanomagnetite, hematite, and iron sulfides.
DEEP-SEA RESEARCH PART I-OCEANOGRAPHIC RESEARCH PAPERS
(2023)
Review
Chemistry, Inorganic & Nuclear
Thomas Mathew, Socrates B. Munoz, Olivier Forni, Alain Tressaud, G. K. Surya Prakash
Summary: Fluorine plays a significant role in the geochemical world, affecting the properties of chemical compounds both on Earth and in extraterrestrial regions. The study of its origin and abundance is crucial for understanding its relevance to terrestrial chemistry and its presence in other planets and star-forming galaxies. The literature review reveals the presence of fluorine in various extraterrestrial regions, indicating its ubiquity in the stellar and interstellar medium. Further research on the fluorine effect in extraterrestrial atmospheres is important due to its growing influence on Earth.
JOURNAL OF FLUORINE CHEMISTRY
(2023)
Article
Chemistry, Physical
Christopher J. Koch, Anushan Alagaratnam, Alain Goeppert, G. K. Surya Prakash
Summary: Phosphate salts have been studied as carbon dioxide capture reagents, but their role in the direct conversion of captured carbon dioxide to hydrogenated products is not well understood. In this study, we report the conversion of captured carbon dioxide to methane in a phosphate-assisted system. While a nickel-based catalyst showed strong inhibition due to unwanted interaction with phosphate species, 5% Ru/Al2O3 catalyst achieved 100% conversion of captured CO2 to methane after 6 hours under 50 bar H-2 at 200 degrees C. The 5% Ru/Al2O3 catalyst also maintained its reactivity over multiple capture/hydrogenation cycles.
SUSTAINABLE ENERGY & FUELS
(2023)
Article
Chemistry, Multidisciplinary
Oliver Y. Gutierrez, Katarzyna Grubel, Jotheeswari Kothandaraman, Juan A. Lopez-Ruiz, Kriston P. Brooks, Mark E. Bowden, Tom Autrey
Summary: Using hydrogen to store energy is crucial for achieving sustainability and addressing climate change. Liquid hydrogen carriers can overcome the challenges of handling molecular hydrogen. The bicarbonate-formate cycle, utilizing formate ions as hydrogen and energy carriers, offers a promising solution. This system combines electrochemical and thermochemical operations and has the potential for CO2 capture and energy storage.
Article
Chemistry, Multidisciplinary
Christopher J. Koch, Vicente Galvan, Alain Goeppert, G. K. Surya Prakash
Summary: The direct conversion of inorganic carbonate salts into methane using Ni/Al2O3 and Ni/CaAl2O4 catalysts under 50 bar of hydrogen at a temperature of 225 degrees C is reported. Water improved the conversion rate and the Ni/Al2O3 catalyst retained 99% of its activity after five hydrogenation cycles. The metal hydroxide was regenerated and reused to capture CO2 for subsequent reactions. Compared to the sequential approach, this integrated route offers energetic and economic benefits for carbon capture and conversion.