Article
Chemistry, Physical
Angel Campos-Lendinez, Nuria Crivillers, Stefan T. Bromley, Concepci o Rovira, Gary W. Breton, Marta Mas-Torrent
Summary: This study successfully prepared self-assembled monolayers (SAMs) of a 1-arylurazole radical on Au surfaces using two different approaches. These SAMs exhibited active radical behavior, with the SAM prepared using the first approach demonstrating greater surface coverage.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Organic
Vera A. Vil', Valentina M. Merkulova, Alexey I. Ilovaisky, Stanislav A. Paveliev, Gennady Nikishin, Alexander O. Terent'ev
Summary: Fluorinated ketones were synthesized via electrochemical method in an undivided cell, with yields ranging from 20% to 85%.
Article
Chemistry, Medicinal
Junhui Lu, Huimin Zhang, Jinhui Yu, Dezun Shan, Ji Qi, Jiawen Chen, Hongwei Song, Minghui Yang
Summary: The study developed a machine learning approach to predict the temperature-dependent site-specific rate constants of hydrogen abstraction reactions, demonstrating robustness in accurately predicting the site-specific and overall rate constants.
JOURNAL OF CHEMICAL INFORMATION AND MODELING
(2021)
Review
Chemistry, Applied
Yi-Chao Li, Yu-Hao Wang, Subarna Jyoti Kalita, Yi-Yong Huang
Summary: This review summarizes the recent advancements in nucleophilic phosphine catalysis for incorporating fluorine/s or fluoroalkyl group/s into organic molecules, focusing on the methodological progress of cycloaddition, addition, and coupling reactions using fluorinated building blocks as electrophilic and/or nucleophilic partners. The article highlights the synthetic strategies, proposed reaction mechanisms, and synthetic utilities of these organofluorine compounds.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Multidisciplinary
Mikhail Feofanov, Vladimir Akhmetov, Ryo Takayama, Konstantin Amsharov
Summary: A novel catalyst-free approach to benzoannulated oxygen-containing heterocycles from fluorinated oligophenylenes is reported, utilizing potassium tert-butoxide as an O2- synthon. The radical nature of the reaction enables nucleophilic substitution and facilitates de-tert-butylation, allowing for multiple annulations and the synthesis of ladder-type O-heteroacenes and oligodibenzofurans.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Review
Chemistry, Applied
Serena Pillitteri, Prabhat Ranjan, Erik V. Van der Eycken, Upendra K. Sharma
Summary: The chemistry of boron compounds has been extensively studied and applied in synthetic and biologically active molecules. The advent of photoredox catalysis has led to a surge in the discovery of suitable radical precursors, with boron playing a prominent role. However, the use of boronic acids and esters in photocatalyzed reactions has received less attention, and methods to enable their involvement have only recently been developed. Nonetheless, this review summarizes novel strategies to unlock their potential as radical precursors in photochemical reactions by exploiting their intrinsic chemical properties.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Energy & Fuels
Zhilin Xi, Mengmeng Li, Xue Li, Linping Lu, Jiawei Wang
Summary: This study investigates the reaction mechanisms involving hydroxyl radicals in coal and the inhibitory effect of hydroxytyrosol on coal spontaneous combustion. The results suggest that hydroxyl radicals are primarily formed through the decomposition of peroxyl radicals, and then they participate in the oxidation reactions of hydrocarbons and oxygen-containing groups in coal. Hydroxytyrosol effectively removes free radicals from coal and inhibits coal spontaneous combustion.
Article
Chemistry, Multidisciplinary
Teruhiko Matsubara, Kenjiro Takemura
Summary: By using alternative process designs without plastics for chemical and biological reactions, researchers can achieve a more sustainable and risk-free reaction process, benefiting future generations.
Review
Chemistry, Physical
Giulio Goti
Summary: This article discusses the application of catalytic radical methods in the functionalization of unsaturated carbohydrates, highlighting the opportunities they offer for new reaction design. These methods overcome the limitations of classical protocols and provide new routes for the synthesis of complex carbohydrates.
Article
Chemistry, Organic
Yi Sun, Fengjiao Liu, Jacob N. Sanders, K. N. Houk
Summary: The influence of steric effects on the rates of hydrogen atom transfer reactions between oxyradicals and alkanes is explored computationally. The study shows that bulky substituents on the radical significantly affect activation barriers and reaction enthalpies, while substituents on the alkane have little effect. The results suggest that the Evans-Polanyi relationship can still describe the HAT reactions between bulky molecules even when steric repulsion effects become important.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Energy & Fuels
Zhilin Xi, Lianquan Suo, Tong Xia
Summary: In this study, the microscopic mechanism of coal spontaneous combustion (CSC) was investigated using computational chemistry. The results revealed that the reactions involved various reactive tissues and free radicals, and the reactions with free radicals played a crucial role. Understanding the key steps and heat generation process of CSC can be achieved through analyzing these reactions.
Article
Multidisciplinary Sciences
Kenji Ota, Kazunori Nagao, Dai Hata, Haruki Sugiyama, Yasutomo Segawa, Ryosuke Tokunoh, Tomohiro Seki, Naoya Miyamoto, Yusuke Sasaki, Hirohisa Ohmiya
Summary: This study demonstrates a light-driven radical-polar crossover mechanism for the tertiary alkylation of phosphorus atoms in nucleotides, enabling the synthesis of alkylphosphonate structures that are difficult to obtain using existing methods.
NATURE COMMUNICATIONS
(2023)
Article
Energy & Fuels
Zhilin Xi, BangXin Jin, Ze Shan
Summary: Research has explored the mechanisms of peroxy radicals in the low temperature oxidation of coal through quantum chemical calculations and analysis of thermodynamic parameters. The study revealed the existence of active sites and different energy barriers and reaction rate constants for chemical adsorption and H transfer reactions involving ROO.. Additionally, an antioxidant enzyme inhibitor compound containing superoxide dismutase (SOD) was found to effectively eliminate ROO., providing theoretical support for coal spontaneous combustion prediction.
Article
Chemistry, Applied
Nicholas D. C. Tappin, Philippe Renaud
Summary: An improved procedure for halogen atom and chalcogen group transfer radical additions is reported, utilizing the thermal decomposition of DTBHN to produce reactive methyl radicals. This initiation method generates gaseous or volatile byproducts for easy purification, with simple reaction conditions and broad scope of application demonstrated. Additionally, an alternative source of radicals, DTBPO, is also shown to be effective under identical conditions.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Multidisciplinary
Yusuke Imamura, Kyohei Takaoka, Yuma Komori, Masanori Nagatomo, Masayuki Inoue
Summary: This study presents a 34-step synthesis of Taxol, involving inter- and intramolecular radical reactions to connect the A- and C-ring fragments and cyclize the B-ring. The A- and C-ring functional groups were then efficiently modified using newly developed selective reactions. The construction of the D-ring and its conjugation with the beta-amino acid led to the successful synthesis of Taxol. This synthesis provides useful insights for the design of multistep syntheses of diverse bioactive natural products.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Biochemistry & Molecular Biology
Damian E. Yerien, Sebastian Barata-Vallejo, Daniela Mansilla, Al Postigo
Summary: The photocatalyzed perfluorohexylation of olefins, alkynes, and electron-rich aromatic compounds in water was achieved, resulting in the incorporation of fluoroalkyl moieties. This is the first example of photocatalyzed atom transfer radical addition (ATRA) reactions carried out exclusively in water, and examples of incorporating fluoroalkyl groups into commercial drugs were reported.
PHOTOCHEMICAL & PHOTOBIOLOGICAL SCIENCES
(2022)
Review
Chemistry, Physical
Sebastian Barata-Vallejo, Damian E. Yerien, Al Postigo
Summary: Due to the need for more environmentally friendly processes in synthetic organic chemistry, the use of photocatalysts found in nature and mimicking natural processes to achieve organic transformations is highly appealing. This article discusses the photocatalysis of oxidation, reduction, carbon-oxygen, carbon-carbon and carbon-sulfur bond formation reactions, as well as E-Z geometrical isomerization reactions, using biological natural pigments, vitamins, cofactors, and compounds with antiviral activity.
Review
Chemistry, Multidisciplinary
Sebastian Barata-Vallejo, Sergio M. Bonesi, Al Postigo
Summary: This article discusses direct fluoroalkoxylation reactions of (hetero)arenes, carbon-carbon multiple bonds, and substitution reactions at Csp(3) carbon centers by CF3O, CHF2O, and (CF3)(2)CFO groups. The emphasis is placed on thermal radical, electron transfer, photocatalytic, electrochemical and redox-neutral radical methods to achieve fluoroalkoxylation reactions. All these methods involve the use of radical fluoroalkoxylating reagents or nucleophilic trifluoromethoxylating sources of CF3O. A summary of all these methods is provided in Table 2.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Organic
Ivan E. Romero, Beatriz Lantano, Al Postigo, Sergio M. Bonesi
Summary: This study systematically investigated the direct irradiation of mono-, di-, and trisubstituted triphenylamine derivatives in acetonitrile as solvent with light of 254 nm. The results showed that the nature of the substituents affected the formation of photoproducts, and the kinetic parameters correlated with the substituent properties were analyzed.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Biochemistry & Molecular Biology
Chryssostomos Chatgilialoglu, Marios G. Krokidis, Annalisa Masi, Sebastian Barata-Vallejo, Carla Ferreri, Barbara Pascucci, Mariarosaria D'Errico
Summary: This study compared the purine lesions in mtDNA and tDNA under specific conditions, finding that mtDNA is less responsive to oxidative or degenerative environments compared to tDNA.
Article
Chemistry, Organic
Damian E. Yerien, Jessica Groppi, Al Postigo, Alberto Credi, Romina S. Conde, Massimo Baroncini, Sebastian Barata-Vallejo
Summary: Modified crown ethers are essential in supramolecular chemistry, and have applications in various fields such as phase transfer catalysis, metal extraction, smart materials, and molecular machines. In this study, a one-pot highly selective photocatalytic fluoroalkylation protocol was developed for the mono-functionalization of benzo substituted crown ethers. With broad applicability and high yield, this method allows for the late-stage functionalization of various aromatic crown ethers, including those involved in mechanically interlocked molecules.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Ivan E. Romero, Al Postigo, Sergio M. Bonesi
Summary: This study investigates the effects of substituents and solvents on the spectroscopic behavior and the photoinduced [6x]-electro-cyclization reaction of substituted triphenylamine derivatives. It is found that triphenylamines with electron-donor substituents produce substituted exo/endo carbazole derivatives, while those with electron-withdrawing substituents form charge transfer complexes (CTCs) instead of carbazoles. The photoreaction is favored by weak electron-acceptor groups in polar solvents. The absorption and fluorescence spectra of these derivatives show dependence on solvent polarity.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Physical
Damian E. E. Yerien, Sebastian Barata-Vallejo, Al Postigo
Summary: This article focuses on a variety of perfluoroalkylation reactions of aliphaticsubstrates, providing examples of their applications and mechanistic details. Synthetic approaches for fluoroalkylation reactions, particularly radical protocols, are documented. Addition reactions of perfluoroalkyl radicals R(F) (R-F=C n F2n+1, n > 1) to unsaturated organicsubstrates are highlighted as a direct and efficient method to access fluoroalkylated scaffolds.
Article
Chemistry, Organic
Ivan E. Romero, Al Postigo, Sergio M. Bonesi
Summary: The effects of substituents and solvents on the spectroscopic behavior and photoinduced [6x]-electrocyclization reaction of substituted triphenylamine derivatives were investigated. Triphenylamines with electron-donor substituents yielded substituted exo/endo carbazole derivatives under direct irradiation in different solvents, while those with electron-withdrawing substituents did not due to the formation of charge transfer complexes (CTCs). Weak electron-acceptor groups in polar solvents favored the photoreaction. The lowest-frequency absorption bands and fluorescence emission spectra of the triarylamines depend on the solvent polarity, showing mirror image behavior for electron-donor substituents and good fluorescence chromophores for formyl, acetyl, and nitro groups. Hammett correlations on the energies of monosubstituted amines showed a bell-shape trend dependent on solvent polarity. The physical quenching of the photoreaction demonstrated that the triplet excited state is the reactive state leading to carbazole derivatives.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Review
Chemistry, Physical
Sebastian Barata-Vallejo, Damian E. Yerien, Al Postigo
Summary: The syntheses and applications of fluorosulfonylated organic compounds have greatly expanded in the past decade due to their versatility in click chemistry reactions. Combining the SO2F group with other functional moieties has increased the diversity and applications of these compounds. Sequential click chemistry protocols involving alkynes and SuFExable groups have been developed to enhance the diversity of scaffolds. This article also discusses the syntheses of various sulfonyl fluorides and compounds containing N-SO2F and O-SO2F bonds, showcasing their reactivity in SuFEx click chemistry and other reactions.
CATALYSIS SCIENCE & TECHNOLOGY
(2023)
