Article
Chemistry, Multidisciplinary
Kritika Keshari, Moumita Bera, Lucia Velasco, Sandip Munshi, Geetika Gupta, Dooshaye Moonshiram, Sayantan Paria
Summary: A terminal (FeOH)-O-III complex has been synthesized and characterized, showing the formation of a ligand radical complex in further reactions mimicking the oxygen rebound step of cytochrome P450. Kinetic analysis revealed the crucial role of a hydrogen atom transfer mechanism in the reactions.
Article
Chemistry, Multidisciplinary
Panisha Nayak, Manisha Nayak, Kiran Meena, Sanjib Kar
Summary: de Visser et al. demonstrated that vanadium(iv)-oxo complexes can generate an efficient oxidizer in the presence of H2O2. The catalytic activities of these complexes have been extensively studied, but not in corrole based ligand systems. In this study, two new oxo(corrolato)vanadium(iv) complexes were synthesized, and an anionic complex was observed. These complexes showed highly efficient oxidizer activity in the presence of H2O2 and KHCO3, with the true catalytic intermediate identified as an oxo(peroxo)(corrolato)vanadium(v) complex.
NEW JOURNAL OF CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Gui Chen, Li Ma, Po-Kam Lo, Chi-Keung Mak, Kai-Chung Lau, Tai-Chu Lau
Summary: Metal oxo complexes can serve as oxidants in chemical and biological systems, with activation by Lewis or Brønsted acids. Weak Lewis and Brønsted acids, such as Ca2+ and CH3CO2H, can efficiently activate RuO4- and exhibit cooperative effects, enhancing the oxidation efficiency.
Article
Chemistry, Multidisciplinary
Jinling Wang, Kai-Peng Hou, Yuzhen Wen, Honglai Liu, Hualin Wang, Khetpakorn Chakarawet, Ming Gong, Xuejing Yang
Summary: By simple cation intercalation, the catalytic pathway of iron-based oxidation systems can be altered, leading to enhanced reaction kinetics. This structural regulation technique is of great significance for sustainable pollutant removal technologies.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Physical
Yasuyuki Yamada, Yusuke Miwa, Yuka Toyoda, Quan Manh Phung, Kin-ichi Oyama, Kentaro Tanaka
Summary: A mu-nitrido-bridged dimer of iron phthalocyanine is an effective molecule-based CH4 oxidation catalyst. In this study, a novel mu-nitrido-bridged heterodimer of iron phthalocyanine and iron porphycene was synthesized, and its CH4 oxidation activity was examined. The heterodimer showed catalytic activity, while the mu-nitrido-bridged iron porphycene dimer decomposed quickly under the same reaction conditions.
CATALYSIS SCIENCE & TECHNOLOGY
(2023)
Article
Chemistry, Multidisciplinary
Monika, Aman, Azaj Ansari
Summary: Calculations based on density functional theory were used to analyze the energy barrier for the formation of terminal metal-oxo from metal hydroperoxo species with buea ligand. The results showed that the energy barriers for the cleavage of the OMIDLINE HORIZONTAL ELLIPSISO bond were higher for late transition metals compared to early transition metals, supporting the concept of the oxo wall.
NEW JOURNAL OF CHEMISTRY
(2022)
Article
Biochemistry & Molecular Biology
Xinzhe Zhong, Caitlin J. Bouchey, Evanta Kabir, William B. Tolman
Summary: By reacting copper-superoxide complexes with dicopper(I) complexes using different ligands, metastable intermediates with (peroxo)dicopper moieties were formed instead of the desired (peroxo)tricopper model under reaction conditions. The structures of these intermediates were proposed to be mu-eta(1): eta(2)-peroxo based on resonance Raman data and consideration of structural preferences for LCuX species.
JOURNAL OF INORGANIC BIOCHEMISTRY
(2021)
Article
Chemistry, Inorganic & Nuclear
Christina Wegeberg, Mathias L. Skavenborg, Andrea Liberato, James N. McPherson, Wesley R. Browne, Erik D. Hedegard, Christine J. McKenzie
Summary: A series of iron(IV) oxo complexes with different donors were prepared in water at different pH values. Differences in reactivities towards C-H substrates were observed, with one complex showing higher reactivity at pH 2. Supramolecular assistance by the first and second coordination spheres in activating the substrate was proposed, and it was noted that slow water oxidation acts as a competing background reaction.
INORGANIC CHEMISTRY
(2021)
Article
Biochemistry & Molecular Biology
Hiromu Ito, Hiromi Kurokawa, Hirofumi Matsui
Summary: Mitochondria, essential organelles for energy production in eukaryotes, generate reactive oxygen species during the process which play pivotal roles in cell signaling and iron homeostasis regulation. The regulation of iron transportation, involving proteins like HCP1, DMT1, and mitoferrin, is increasingly understood in relation to mitochondrial reactive oxygen species and diseases.
ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS
(2021)
Article
Chemistry, Multidisciplinary
John A. Seed, Letitia Birnoschi, Erli Lu, Floriana Tuna, Ashley J. Wooles, Nicholas F. Chilton, Stephen T. Liddle
Summary: Characterizing the electronic ground state of metal complexes is essential, and magnetometry provides crucial insights. Uranium(IV) complexes often exhibit non-degenerate spin-orbit ground states, but some show near-doubly degenerate states due to the donor properties of oxo and imido anions. Traditional crystal field arguments are valuable for understanding the electronic structure and magnetic properties of these complexes, highlighting the need for re-evaluation.
Review
Chemistry, Inorganic & Nuclear
Tomoya Ishizuka, Hideki Sugimoto, Shinobu Itoh, Takahiko Kojima
Summary: Ruthenium and osmium complexes play crucial roles in oxidation reactions, generating high-valent species through peroxide activation and proton-coupled electron transfer. These complexes provide insights into oxidation mechanisms and exhibit unique reactivity.
COORDINATION CHEMISTRY REVIEWS
(2022)
Article
Chemistry, Multidisciplinary
Mohamed M. Aboelnga
Summary: This study investigates the mechanism and role of key residues in cytochrome c peroxidase through quantum chemistry calculations and analysis, providing valuable findings for solving the ambiguity of its exact mechanism and contributing to the understanding of peroxidases with similar heme pockets.
Article
Chemistry, Multidisciplinary
D. M. Ramitha Y. P. Rupasinghe, Makayla R. Baxter, Himanshu Gupta, Andrew T. Poore, Robert F. Higgins, Matthias Zeller, Shiliang Tian, Eric J. Schelter, Suzanne C. Bart
Summary: This study presents the first synthesis of a non-uranyl, f-element oxo complex from dioxygen in dry air. The characterization of the complexes using various spectroscopic techniques confirmed their electronic structures.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Inorganic & Nuclear
Guangjian Liao, Fuming Mei, Zhuqi Chen, Guochuan Yin
Summary: This study demonstrates an improved dioxygen activation by introducing Lewis acid into Fe-II(BPMEN)(OTf)(2) complex, leading to successful catalytic reactions of tryptophan 2,3-dioxygenase and olefinic CC ? bond oxygenation. The results reveal the enhanced electrophilic oxygenation capability of the putative iron(III) superoxo species through electrostatic interaction with Lewis acid.
DALTON TRANSACTIONS
(2022)
Article
Chemistry, Inorganic & Nuclear
Monika, Azaj Ansari
Summary: Metal-superoxo species play a significant role in metal-mediated catalytic reactions, and their reactivity is influenced by factors such as metal ions and ligand ring size. In this study, DFT calculations and mechanistic studies were performed to investigate the electronic structures of metal-superoxo species and the C-H bond activation. It was found that electron density at the distal oxygen atom affects C-H bond activation, and the initial hydrogen abstraction is the rate-determining step. Additionally, the ring size of the ligand can affect the reactivity of the metal-superoxo species in C-H bond activation.
DALTON TRANSACTIONS
(2022)
Article
Chemistry, Organic
Jian-Ping Chen, Yi Li, Chao Liu, Tianyi Wang, Lung Wa Chung, Ming-Hua Xu
Summary: This study achieves a highly enantioselective rhodium-catalyzed intermolecular hydroarylation of alpha-aminoalkyl acrylates using a chiral bicyclo[3.3.0] diene ligand, leading to a broad range of alpha-aryl-methyl-substituted beta(2)-, gamma(2)-, and delta(2)-amino esters with excellent enantioselectivities (up to 98% ee) under mild conditions. This method provides a new pathway for constructing structurally interesting benzo-fused heterocyclic molecules and the corresponding beta(2)-, gamma(2)-, and delta(2)-amino acids.
Article
Chemistry, Multidisciplinary
Xiaoyong Du, Ye Xiao, Yuhong Yang, Ya-Nan Duan, Fangfang Li, Qi Hu, Lung Wa Chung, Gen-Qiang Chen, Xumu Zhang
Summary: The enantioselective hydrogenation of cyclic and acyclic tetrasubstituted alpha, beta-unsaturated carboxylic acids via cobalt(II) catalysis demonstrated broad substrate scope and excellent enantiocontrol. Combined experimental and computational mechanistic studies supported a Co-II catalytic cycle involving migratory insertion and sigma-bond metathesis processes, with enantioselectivity possibly originating from the steric effect between the phenyl groups of the ligand and the substrate.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Physical
Zeyin Yan, Xin Li, Lung Wa Chung
Summary: The quantum refinement technique, combining crystallographic data with computational chemistry methods, can improve the accuracy of metalloprotein structures, especially those containing transition metal ions. Multiscale quantum refinement schemes have been developed to refine the local metal binding sites in metalloproteins efficiently.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2021)
Article
Chemistry, Physical
Qian Wang, Jialing Lan, Rong Liang, Yihao Xia, Lei Qin, Lung Wa Chung, Zhiping Zheng
Summary: In this study, a new application of the Grubbs catalysts in hydrogen production from aqueous-phase methanol reforming was reported, showing that the G-III catalyst achieved the best performance among those tested and can also be used for other dehydrogenation reactions. Mechanistic studies and DFT calculations revealed an unusual substrate-assisted metathesis pathway, shedding light on the reaction mechanism and suggesting new opportunities in catalyst design for clean and renewable energies.
Article
Chemistry, Multidisciplinary
Jian-Hong Fan, Jing-Jing Wang, Fangfang Li, Guannan Wang, Qiang Guo, Lung Wa Chung, Chuang-Chuang Li
Summary: This study describes the first and asymmetric total synthesis of phomarol, a rare C25 steroid, using a mild acid-promoted type I [5 + 2] cycloaddition followed by regio- and chemoselective bond cleavage and aromatization cascade. The stereoselectivity of cycloadditions was controlled using hydrogen bonding between the hydroxy group and oxidopyrylium ylide. The highly functionalized tetrahydropyran ring of phomarol was efficiently produced based on a suggested biomimetic pathway.
Review
Chemistry, Multidisciplinary
Jialing Lan, Xin Li, Yuhong Yang, Xiaoyong Zhang, Lung Wa Chung
Summary: Homogeneous catalysis and biocatalysis have found wide applications in synthetic, medicinal, and energy chemistry as well as synthetic biology. Computational chemistry has become an essential tool to understand structures and reaction mechanisms in catalysis. The synergy between computational and experimental chemistry deepens our understanding of mechanisms and promotes the design of new catalysts.
ACCOUNTS OF CHEMICAL RESEARCH
(2022)
Article
Chemistry, Multidisciplinary
Gongyi Liu, Lini Zheng, Kui Tian, Haifeng Wang, Lung Wa Chung, Xumu Zhang, Xiu-Qin Dong
Summary: A highly efficient Ir/bisphosphine-thiourea catalytic system, ZhaoPhos, has been successfully developed for the asymmetric hydrogenation (AH) of challenging aryl substituted unprotected indoles, showing high reactivity and excellent stereoselective control. Various chiral indoline derivatives were obtained in good to high yields with excellent stereoselectivities. Anion-binding activation strategy played an important role in achieving both high reactivity and excellent stereoselectivity.
Article
Chemistry, Multidisciplinary
Tian-Yi Wang, Xiao-Xuan Chen, Dong-Xing Zhu, Lung Wa Chung, Ming-Hua Xu
Summary: A highly selective C(sp(2))-H functionalization reaction catalyzed by rhodium(I)-diene has been developed, enabling the synthesis of α,β-unsaturated esters containing heteroatoms under mild reaction conditions. Mechanistic studies show that the substrate affects the reaction rate and selectivity.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Inorganic & Nuclear
Jialing Lan, Tonghuan Zhang, Yuhong Yang, Xin Li, Lung Wa Chung
Summary: Transition-metal-catalyzed amination of aryl halides is a useful method for synthesizing medicinal compounds, organic functional materials, and agrochemical compounds. A systematic DFT study has revealed the mechanism of Co(I)-catalyzed amination of aryl halides, with dissociative C-I activation pathway being the most favorable.
INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Physical
Zhifeng Ma, Zeyin Yan, Xin Li, Lung Wa Chung
Summary: In this study, the effects of external electric fields (EEFs) on three reactions involving hydrogen or carbon were extensively investigated. The study revealed that oriented EEFs can significantly reduce the barrier and increase the reaction rates. Furthermore, EEFs can modulate tunneling reactions and control the site selectivity of molecules with similar reactive sites.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Chuan Qin, Zhidao Huang, Song-Bai Wu, Zhuangxing Li, Yuhong Yang, Xin Zhang, Guixia Liu, Yun-Dong Wu, Lung Wa Chung, Zheng Huang
Summary: This study challenges a widely accepted assumption in organometallic chemistry that unactivated aliphatic C(sp3)-H bonds are less reactive than aromatic C(sp2)-H bonds within the same molecule. The researchers demonstrate that a pincer-ligated iridium complex can selectively catalyze intramolecular dehydrogenative silylation of unactivated delta-C(sp3)-H bonds, leading to the formation of 5-membered silolanes. Furthermore, chiral silolanes can be further oxidized to produce enantiopure beta-aryl-substituted 1,4-diols.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Multidisciplinary
Fangrui Zheng, Yuhong Yang, Siye Wu, Shunan Zhao, Yifan Zhu, Huimin Su, Jun-Feng Dai, Zeyin Yan, Lung Wa Chung, Keith Man-Chung Wong
Summary: In contrast to the well-studied dirhodium(II) complexes and iridium(III) complexes, neutral or dicationic dinuclear iridium(II) complexes with unsupported ligands are relatively unexplored. In this study, a series of tetracationic dinuclear iridium(II) complexes with long bond distances and photoluminescent properties were synthesized and characterized. It was found that these complexes exhibit high stability due to London dispersion interactions, despite the long Ir(II)-Ir(II) bond lengths, and show potential for further photoreactivity studies involving the generation of iridium(II) radical monomers.
COMMUNICATIONS CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Mingkang Zhou, Yaodong Lin, Xiao-Xuan Chen, Guangqing Xu, Lung Wa Chung, Wenjun Tang
Summary: We report the chiral diboron-templated asymmetric homocoupling of aryl alkyl ketimines, leading to the formation of chiral vicinal tetrasubstituted diamines with high enantioselectivities and good to high yields. This powerful and efficient reaction is achieved by rational design and engineering of chiral diborons, which participate in a [3,3]-sigmatropic rearrangement. DFT studies reveal that different conformational assembling strategies of chiral diborons ensure the excellent enantioselectivity in the tight concerted transition states.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Organic
Rong Liang, Qinghai Zhou, Xin Li, Ming Wah Wong, Lung Wa Chung
Summary: The macrocycle effect of [2]rotaxane on the highly trans-stereoselective cyclization reaction of N-benzylfumaramide has been extensively studied. Computational results suggest that the most favorable mechanism involves deprotonation of a N-benzyl group of the fumaramide substrate by CsOH, followed by C-C bond formation and protonation by an amide functional group of the macrocycle. The trans-selective cyclization within the rotaxane is attributed to higher distortion energy caused by the twisted cis-fumaramide conformation enforced by the rotaxane.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Xin Chang, Xue-Tao Liu, Fangfang Li, Yuhong Yang, Lung Wa Chung, Chun-Jiang Wang
Summary: A series of benzofulvenes without electron-withdrawing substituents were used as 2π-type dipolarophiles in Cu(i)-catalyzed asymmetric 1,3-dipolar cycloaddition reactions. The non-benzenoid aromatic characteristic of benzofulvenes served as a key driving force for their activation. The methodology allowed for the synthesis of multi-substituted chiral spiro-pyrrolidine derivatives with exclusive chemo-/regioselectivity and high to excellent stereoselectivity.