Article
Energy & Fuels
Yaozong Duan, Anhao Zhong, Zhen Huang, Dong Han
Summary: This study calculated the rate constants of the reaction between cyclopentanol and hydroxyl radical using multistructural canonical variational transition state theory. The results highlighted the importance of variational and multistructural torsional anharmonicity effects, with quantum tunneling effect being negligible. While the total rate constants were in good agreement with literature estimates, significant discrepancies were observed in the branching ratios of reaction channels.
Correction
Chemistry, Physical
Wenqi Chen, Xuan Guo, Lifang Chen, Ruiming Zhang, Yan Li, Haisong Feng, Xuefei Xu, Xin Zhang
Summary: The article provides a corrected version of a kinetics study on hydrogen abstraction reactions of cyclopentane by hydrogen, methyl, and ethyl radicals, conducted by Wenqi Chen et al. This study was published in Phys. Chem. Chem. Phys. in 2021.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Thermodynamics
Yaozong Duan, Zhen Huang, Dong Han
Summary: This study investigates the temperature-dependent rate constants and branching ratios of hydrogen atom abstraction reactions from n-propanol and iso-propanol by HO2 radical. The multistructural torsional anharmonicity effects significantly influence the calculation of rate constants, highlighting the importance of accurate calculation efforts for predicting reaction pathways and kinetic behavior. Incorporating the newly calculated rate constants into a chemical kinetic model results in decreased fuel reactivity and better prediction of key oxidation intermediates in propanol oxidation.
COMBUSTION AND FLAME
(2021)
Article
Chemistry, Multidisciplinary
Haomin Wang, Meilian Zhao, Qiwen Zuo, Mingxing Liu, Xinyu He, Zhiguo Wang, Yuxi Sun, Ruojing Song, Yunju Zhang
Summary: The conversion mechanisms and kinetics of propadiene (CH2 = C=CH2) induced by NO3 were investigated using density functional theory (DFT) and transition state theory (TST). The addition pathways of NO3 to generate IM1 (CH2ONO2CCH2) and IM2 (CH2CONO2CH2) play a significant role, with P3 (CH2CONOCHO + H) being the dominant addition/elimination product. It was found that one H atom from the -CH2- group needs to be abstracted by NO3 radicals in order to form the final product h-P1 (CH2CCH + HNO3). The H-abstraction pathway is not important for the propadiene + NO3 reaction due to the high barrier. The computed k(tot) value of propadiene reacting with NO3 at 298 K is 3.34 x 10(-15) cm(3) per molecule per s, which agrees with experimental observations. The computed lifetime of propadiene oxidized by NO3 radicals was estimated to be 130.16-6.08 days at 200-298 K and an altitude of 0-12 km. This study offers insights into the transformation of propadiene in a complex environment.
Article
Chemistry, Physical
Indu Sekhar Roy, Malte Doentgen, Can Huang, Wassja Kopp, Kai Leonhard
Summary: Biohybrid fuels, including 1,3-dioxolane, offer a promising solution for greener transportation. However, there is limited data on the oxidation kinetics of 1,3-dioxolane. This study presents the reaction kinetics of O2 addition to 1,3-dioxolanyl radicals and compares it to similar fuel molecules. The dominant pathway following the oxidation of 1,3-dioxolanyl radicals is the ring-opening beta-scission reactions of the dioxolane hydroperoxy species.
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
Article
Chemistry, Physical
Indu Sekhar Roy, Malte Doentgen, Can Huang, Wassja Kopp, Kai Leonhard
Summary: Biohybrid fuels, such as 1,3-dioxolane produced from inedible biomass, show promise in making transportation more environmentally friendly. However, there is limited data on the kinetics of low-temperature oxidation of 1,3-dioxolane. This study presents the reaction kinetics of O-2 addition to 1,3-dioxolanyl radicals and compares it to similar fuel molecules. The results show that the ring-opening beta-scission reactions dominate the oxidation of 1,3-dioxolanyl radicals.
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
Article
Energy & Fuels
Marco Osvaldo Vigueras-Zuniga, Maria Elena Tejeda-del-Cueto, Syed Mashruk, Marina Kovaleva, Cesar Leonardo Ordonez-Romero, Agustin Valera-Medina
Summary: Recent studies have shown that ammonia could potentially serve as an energy carrier to replace natural gas in gas combustion. Research has focused on understanding radical formation during the combustion of ammonia and methane blends.
Article
Engineering, Environmental
Lihua Yang, Weiqi Su, Yingyao He, Binhua Yan, Lijuan Luo, Tiangang Luan
Summary: This study aims to investigate the transformation of E2 in water containing fresh or aged DOM surrogates. The results showed that aged DOM produced higher concentrations of hydroxyl radicals, which contributed to the removal of E2. Additionally, the removal of E2 was enhanced by increasing DOM concentration, dissolved oxygen, and light supply. These findings have important implications for understanding the biogeochemical cycle and risk assessment of E2 in natural aquatic environments.
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
Energy & Fuels
Zhe Ren, Yaozong Duan, Wenming Yang, Dong Han
Summary: The rate constants for the H-abstraction reactions of C5H12 + NO2 were calculated using high-accuracy electronic structure calculations and transition state theory. The results indicate that implementing these reaction rate constants can improve the predictive performance of kinetic models and enhance the understanding of the mutual reactions between large hydrocarbon fuels and NOx.
Article
Chemistry, Physical
Anita Schneiker, Sandor Gobi, Prasad Ramesh Joshi, Gabor Bazso, Yuan-Pern Lee, Gyorgy Tarczay
Summary: The reaction of H atoms with glycine at 3.1 K in para-H-2 was studied, leading to the formation of C-a-glycyl radical with high selectivity. The radical is sensitive to UV light and can decompose into iminoacetic acid and H atom. This suggests that a-amino acids can be formed from glycine via the C-a-glycyl radical in non-energetic mechanisms in the solid phase of the interstellar medium.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Thermodynamics
Yuxiang Zhu, Chong-Wen Zhou, Alexander A. Konnov
Summary: In this study, the reaction kinetics of hydrogen-abstraction reactions from methoxymethanol by various radicals were investigated using high-level ab initio calculations. It was found that the H-abstraction reactions from the secondary carbon atom of methoxymethanol are favored pathways. Different radicals have different rate constants for hydrogen-abstraction reactions at different temperatures.
COMBUSTION AND FLAME
(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
Chemistry, Multidisciplinary
Guanqi Qiu, Chi-Li Ni, Robert R. Knowles
Summary: We report a diagnostic framework for elucidating the mechanisms of photoredox-based hydrogen isotope exchange (HIE) reactions based on hydrogen/deuterium (H/D) fractionation. The traditional thermal HIE methods proceed by reversible bond cleavage and bond reformation steps, while light-driven HIE reactions can proceed via multiple, non-degenerate sets of elementary steps. The fractionation method presented here extracts information regarding the nature of the key bond-forming and bond-breaking steps.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Physical
Jonas Elfert, Anup Bhunia, Constantin G. Daniliuc, Armido Studer
Summary: In this study, a radical transformation that enables intramolecular oxygen atom transfer to alkenes using the nitro functionality in nitroarenes as an oxygen donor is disclosed. The reaction proceeds via iron-catalyzed metal hydrogen atom transfer to alkenes and subsequent oxygenation, resulting in alkene hydration. Compared to intermolecular radical oxygenation, the intramolecular variant offers advantages, particularly in terms of diastereoselective radical hydration of conformationally flexible alkenes. The aryl moiety connecting the reactive NO2-functionality to the alkene substrate can be cleaved after oxygen transfer, yielding products derived from a formal diastereoselective intermolecular alkene hydration. Additionally, the resulting aniline entity after oxygen transfer can be used for the construction of nitrogen-containing heterocycles.
Article
Chemistry, Applied
Li-Li Zhu, Lifang Tian, Hui Zhang, Lina Xiao, Wen Luo, Bin Cai, Haifeng Wang, Chunjie Wang, Guanglu Liu, Chaoyu Pei, Yahui Wang
ADVANCED SYNTHESIS & CATALYSIS
(2019)
Article
Chemistry, Organic
Enhui Ji, Haiwen Meng, Yue Zheng, Velayudham Ramadoss, Yahui Wang
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2019)
Review
Chemistry, Organic
Yue Zheng, Xiaoqing Shao, Velayudham Ramadoss, Lifang Tian, Yahui Wang
SYNTHESIS-STUTTGART
(2020)
Review
Chemistry, Multidisciplinary
Velayudham Ramadoss, Yue Zheng, Xiaoqing Shao, Lifang Tian, Yahui Wang
Summary: Carboxylic acids are considered environmentally benign alternatives in various organic transformations due to their non-toxic, stable, and inexpensive properties. Electrochemical decarboxylation has emerged as an efficient methodology for carbon-carbon or carbon-heteroatom bond formations, providing a green and sustainable protocol without the need for chemical oxidants and strong bases. This method also shows good tolerance with various functional groups.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Physical
Shuo Wang, Zhimin Xu, Yahui Wang, Lifang Tian
Summary: The dehydroxylative transformations to form C-N and C-halogen bonds assisted by triphenylphosphine via electrochemical method involve the oxidation of Ph3P to generate alkoxy phosphonium intermediate, which can then be attacked by nucleophiles. Depending on the structure of the alcohol, stable alkyl cations or direct formation of C-halogen bonds can be achieved through different reaction pathways.
MOLECULAR CATALYSIS
(2021)
Article
Chemistry, Organic
Haiwen Meng, Kunhui Sun, Zhimin Xu, Lifang Tian, Yahui Wang
Summary: An external oxidant-free protocol utilizing trivalent phosphine under mild electrochemical conditions to generate isocyanates from hydroxamic acids was reported. This method offers a broadly applicable procedure to access isocyanate intermediates.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Zhimin Xu, Yue Zheng, Lifang Tian, Yahui Wang
Summary: A new six-step synthesis method with 42% overall yield for bempedoic acid is reported in this paper, with ketone formation by electrochemical decarboxylation of dialkylated malonic acid introduced as the key step. This method uses mild conditions and its high efficiency makes it potentially suitable for industrial production.
SYNTHESIS-STUTTGART
(2021)
Article
Chemistry, Organic
Hongyu Wang, Zhihui Wang, Guo Zhao, Velayudham Ramadoss, Lifang Tian, Yahui Wang
Summary: In this study, an efficient deoxygenative C(sp(3))-C(sp(3)) bond formation reaction is achieved through the electrochemical reduction of alcoholic phosphates or sulfonates with aldehydes or ketones. The reaction proceeds under electrochemical conditions, where the alcohol derivatives of phosphates undergo single-electron reduction to generate alkyl radicals, which are further reduced at the cathode to carbanions and then react with carbonyl compounds.
Review
Chemistry, Organic
Yue Zheng, Lifang Tian, Velayudham Ramadoss, Hui Zhang, Li-Li Zhu, Yahui Wang
SYNTHESIS-STUTTGART
(2022)
Article
Chemistry, Organic
Li-Li Zhu, Lifang Tian, Kunhui Sun, Yiwen Li, Guanglu Liu, Bin Cai, Hui Zhang, Yahui Wang
Summary: This study reports a new method for N-2-selective beta-thioalkylation of benzotriazoles with unactivated alkenes and styrenes, which exhibits excellent stereospecificity, simple mild conditions, and high functional group tolerance.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Zhihui Wang, Xiaoqian Zhao, Hongyu Wang, Xiuyun Li, Zhimin Xu, Velayudham Ramadoss, Lifang Tian, Yahui Wang
Summary: In this study, nonactivated alcohols and arene compounds were used in an electrochemical dehydroxylative arylation reaction to construct C(sp(3))-C(sp(2)) bonds. The PIII reagent underwent single-electron anodic oxidation and cathodic reduction reactions, resulting in the generation of radical intermediates for the coupling reaction to form dehydroxylative arylated products.
Article
Chemistry, Multidisciplinary
Kunhui Sun, Zhimin Xu, Velayudham Ramadoss, Lifang Tian, Yahui Wang
Summary: Electrochemical reduction via paired electrolysis is used for the deoxygenative reduction of ketones. The spontaneous beta-scission of phosphoranyl radicals plays a crucial role in the cleavage of C-O bonds.
CHEMICAL COMMUNICATIONS
(2022)
Review
Chemistry, Organic
Xiaoqing Shao, Yue Zheng, Velayudham Ramadoss, Lifang Tian, Yahui Wang
ORGANIC & BIOMOLECULAR CHEMISTRY
(2020)
Article
Chemistry, Multidisciplinary
Zhimin Xu, Yue Zheng, Zhihui Wang, Xiaoqing Shao, Lifang Tian, Yahui Wang
CHEMICAL COMMUNICATIONS
(2019)
Article
Chemistry, Multidisciplinary
Li-Li Zhu, Lifang Tian, Bin Cai, Guanglu Liu, Hui Zhang, Yahui Wang
CHEMICAL COMMUNICATIONS
(2020)
