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Journal articles on the topic 'Stepwise mechanism'

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Published: 5 June 2025
Last updated: 24 June 2025

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1

Yuzenkova, Yulia, Aleksandra Bochkareva, Vasisht R. Tadigotla, et al. "Stepwise mechanism for transcription fidelity." BMC Biology 8, no. 1 (2010): 54. http://dx.doi.org/10.1186/1741-7007-8-54.

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2

YU, LINGJUAN, DACHENG FENG, MAOXIA HE, RUI LI та ZHENGTING CAI. "THEORETICAL STUDY ON HYDROLYSIS MECHANISM OF β-PHOSPHOLACTAMS". Journal of Theoretical and Computational Chemistry 05, spec01 (2006): 421–31. http://dx.doi.org/10.1142/s0219633606002362.

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The neutral hydrolysis mechanisms of a simple β-phospholactam with and without water-assisted reaction have been studied by using quantum chemical method at HF/6-31G**, MP2/6-31G** and B3LYP/6-31G** levels, respectively. The reaction can proceed by two different mechanisms: concerted and stepwise. There are two pathways in stepwise, i.e. pathway a and b, and the energy barriers of them are close. The energy barriers of water-assisted hydrolysis of β-phospholactam are obviously lower than those of no-water-assisted hydrolysis system. The energy barriers of stepwise mechanism are much lower than those of the concerted pathway in both cases. The solvent effects have been considered by means of a polarizable continuum model. The hydrolysis mechanism of β-phospholactam with that of the β-lactam and β-sultam was compared.
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3

Islam, Zahidul, Timothy S. Strutzenberg, Ilya Gurevic, and Amnon Kohen. "Concerted versus Stepwise Mechanism in Thymidylate Synthase." Journal of the American Chemical Society 136, no. 28 (2014): 9850–53. http://dx.doi.org/10.1021/ja504341g.

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4

Slepetz, Brad, and Miklos Kertesz. "Divacancies in diamond: a stepwise formation mechanism." Phys. Chem. Chem. Phys. 16, no. 4 (2014): 1515–21. http://dx.doi.org/10.1039/c3cp53384k.

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5

Cheng, Yi-Han, Yu-Cheng Zhu, Wei Kang, Xin-Zheng Li, and Wei Fang. "Determination of concerted or stepwise mechanism of hydrogen tunneling from isotope effects: Departure between experiment and theory." Journal of Chemical Physics 156, no. 12 (2022): 124304. http://dx.doi.org/10.1063/5.0085010.

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Isotope substitution is an important experimental technique that offers deep insight into reaction mechanisms, as the measured kinetic isotope effects (KIEs) can be directly compared with theory. For multiple proton transfer processes, there are two types of mechanisms: stepwise transfer and concerted transfer. The Bell–Limbach model provides a simple theory to determine whether the proton transfer mechanism is stepwise or concerted from KIEs. Recent scanning tunneling microscopy (STM) experiments have studied the proton switching process in water tetramers on NaCl(001). Theoretical studies predict that this process occurs via a concerted mechanism; however, the experimental KIEs resemble the Bell–Limbach model for stepwise tunneling, raising questions on the underlying mechanism or the validity of the model. We study this system using ab initio instanton theory, and in addition to thermal rates, we also considered microcanonical rates, as well as tunneling splittings. The instanton theory predicts a concerted mechanism, and the KIEs for tunneling rates (both thermal and microcanonical) upon deuteration are consistent with the Bell–Limbach model for concerted tunneling but could not explain the experiments. For tunneling splittings, partial and full deuteration change the size of it in a similar fashion to how they change the rates. We further examined the Bell–Limbach model in another system, porphycene, which has both stepwise and concerted tunneling pathways. The KIEs predicted by instanton theory are again consistent with the Bell–Limbach model. This study highlights differences between KIEs in stepwise and concerted tunneling and the discrepancy between theory and recent STM experiments. New theory/experiments are desired to settle this problem.
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6

Thakur, Rahul. "Elucidation the Synthesis of an Antibiotic Medicine Chloramphenicol Palmitate with its Stepwise Mechanism." International Journal of Science and Research (IJSR) 10, no. 12 (2021): 365–76. http://dx.doi.org/10.21275/mr211206175033.

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7

Ehrlich, Joel I., Chi-Ching Hwang, Paul F. Cook, and John S. Blanchard. "Evidence for a Stepwise Mechanism of OMP Decarboxylase." Journal of the American Chemical Society 121, no. 29 (1999): 6966–67. http://dx.doi.org/10.1021/ja990737s.

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8

Purohit, Prasad, Ananya Mitra, and Anthony Auerbach. "A stepwise mechanism for acetylcholine receptor channel gating." Nature 446, no. 7138 (2007): 930–33. http://dx.doi.org/10.1038/nature05721.

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9

Siadati, Seyyed Amir. "Beyond the Alternatives that Switch the Mechanism of the 1,3-Dipolar CyCloadditions from Concerted to Stepwise or Vice Versa: A Literature Review." Progress in Reaction Kinetics and Mechanism 41, no. 4 (2016): 331–44. http://dx.doi.org/10.3184/146867816x14719552202168.

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For several decades, the concerted or stepwise character of the mechanism of the 1,3-dipolar cycloaddition reaction has been one of the most debated issues in the field of organic chemistry. The significance of this problem is due to the fact that in a catalyst-free 1,3-dipolar cycloaddition, when the mechanism switches from concerted to stepwise, the stereospecificity is lost and thus unwanted stereoisomers may emerge. The first proposals about the mechanism of the 1,3-dipolar reaction were due to Huisgen (concerted model) and subsequently by Firestone (two-step diradical channel) in the 1960s. After a decade of debate, most researchers accepted the concerted model for the reaction, but during these years, researchers reported some examples of the stepwise mechanism for catalyst-free 1,3-dipolar cycloadditions. This review attempts to find a number of factors that could influence the reaction channels and switch the mechanism from concerted to stepwise, or vice versa.
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10

Huang, Ming, and Darrin M. York. "Linear free energy relationships in RNA transesterification: theoretical models to aid experimental interpretations." Phys. Chem. Chem. Phys. 16, no. 30 (2014): 15846–55. http://dx.doi.org/10.1039/c4cp01050g.

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11

Wang, Liqun, Sen Yang, Yin Zhang та ін. "Stepwise Growth of Hollow Hexagonalα-Fe2O3Nanocrystals". Journal of Nanomaterials 2016 (2016): 1–5. http://dx.doi.org/10.1155/2016/4103847.

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Magnetic nanocrystals have attracted much attention in various fields because of their fundamental size and shape dependent magnetism and many technological applications. In this study, hollow hexagonalα-Fe2O3nanocrystals were synthesized using a normal hydrothermal method. A full growth evolution map of nanocrystals with different shapes was investigated to elucidate the growth mechanism. We had demonstrated the growth mechanism using the selective adsorption and dissolution theory and interestingly found that K+cations were also a key point during the process ofα-Fe2O3nanocrystals growing. At last, the magnetic properties of the hexagonalα-Fe2O3nanocrystals were also investigated.
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12

LI, RUI, YENG-TSENG WANG, and CHENG-LUNG CHEN. "COMPUTATIONAL MODELING STUDY ON METABOLISM MECHANISM OF OSELTAMIVIR." Journal of Theoretical and Computational Chemistry 12, no. 05 (2013): 1350037. http://dx.doi.org/10.1142/s0219633613500375.

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Oseltamivir (OTV) is widely used in the treatment of both influenza virus A and B infections. Additionally, OTV is an effective antiviral drug in treating the 2009 A ( H1N1 ) influenza virus. Clinical studies concluded that OTV is readily extensively converted to the active carboxylate metabolite after oral administration. In order to investigate the metabolism mechanism of OTV, we carried out density functional theory (DFT) quantum mechanical calculations. The molecule orbital (MO) theory and natural population analysis (NPA) were also employed to help understanding the reaction mechanism. All possible reaction pathways for OTV metabolism are considered, involving hydrolysis of ester and amide. Two mechanisms were considered in this work, viz. concerted mechanism and stepwise mechanism. Our results indicate the stepwise mechanism is more favorable in both hydrolysis reactions and the rate-determining stage is the formation of the tetrahedral intermediate. In addition, the hydrolysis reactions can be assisted by substrate NH2 group and solvent water molecules. The substrate-assisted mechanism for the formation of the carboxylate metabolite is the most favorable one.
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13

Ramachandran, Ravindranath, Nicholas C. Payne, and Richard J. Puddephatt. "Hydridotriplatinum chemistry and a stepwise electrophilic ligand substitution mechanism." Journal of the Chemical Society, Chemical Communications, no. 2 (1989): 128. http://dx.doi.org/10.1039/c39890000128.

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14

Chen, Wei-Hao, Xuejiao J. Gao, and Xingfa Gao. "Methanol-Assisted Phthalimide Ring Opening: Concerted or Stepwise Mechanism?" Journal of Physical Chemistry A 122, no. 12 (2018): 3115–19. http://dx.doi.org/10.1021/acs.jpca.7b11347.

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15

Renfang, Li, Sun Luping, and Guo Sidai. "The Stepwise Pricing Mechanism Research of Residents’ Living Power." Energy Procedia 5 (2011): 1371–76. http://dx.doi.org/10.1016/j.egypro.2011.03.237.

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16

Sekiguchi, Hikaru, Hee-Cheol Kang, Gilles Tersac, and Bernard Sillion. "Thermal polymerization of arylacetylenes: A stepwise activated monomer mechanism." Makromolekulare Chemie. Macromolecular Symposia 47, no. 1 (1991): 317–28. http://dx.doi.org/10.1002/masy.19910470127.

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17

Pitsch, Chloe E., та Xiaotai Wang. "Aluminum(i) β-diketiminato complexes activate C(sp2)–F and C(sp3)–F bonds by different oxidative addition mechanisms: a DFT study". Chemical Communications 53, № 58 (2017): 8196–98. http://dx.doi.org/10.1039/c7cc03503a.

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DFT computations reveal different reaction mechanisms for the oxidative addition of C(sp<sup>2</sup>)–F and C(sp<sup>3</sup>)–F bonds to the Al(i) complexes: a concerted mechanism for C(sp<sup>2</sup>)–F and a stepwise mechanism for C(sp<sup>3</sup>)–F involving fluoride transfer and the formation and recombination of an ion pair.
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18

Wang, Shu, Qingya Shen, Guangju Chen, Jimin Zheng, Hongwei Tan, and Zongchao Jia. "The phosphatase mechanism of bifunctional kinase/phosphatase AceK." Chem. Commun. 50, no. 91 (2014): 14117–20. http://dx.doi.org/10.1039/c4cc05375c.

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19

Pavez, Paulina, Daniela Millán, Javiera Morales, Mabel Rojas, Daniel Céspedes, and José G. Santos. "Reaction mechanisms in ionic liquids: the kinetics and mechanism of the reaction of O,O-diethyl (2,4-dinitrophenyl) phosphate triester with secondary alicyclic amines." Organic & Biomolecular Chemistry 14, no. 4 (2016): 1421–27. http://dx.doi.org/10.1039/c5ob02128f.

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20

Vermaas, Josh V., Riin Kont, Gregg T. Beckham, et al. "The dissociation mechanism of processive cellulases." Proceedings of the National Academy of Sciences 116, no. 46 (2019): 23061–67. http://dx.doi.org/10.1073/pnas.1913398116.

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Cellulase enzymes deconstruct recalcitrant cellulose into soluble sugars, making them a biocatalyst of biotechnological interest for use in the nascent lignocellulosic bioeconomy. Cellobiohydrolases (CBHs) are cellulases capable of liberating many sugar molecules in a processive manner without dissociating from the substrate. Within the complete processive cycle of CBHs, dissociation from the cellulose substrate is rate limiting, but the molecular mechanism of this step is unknown. Here, we present a direct comparison of potential molecular mechanisms for dissociation via Hamiltonian replica exchange molecular dynamics of the model fungal CBH, Trichoderma reesei Cel7A. Computational rate estimates indicate that stepwise cellulose dethreading from the binding tunnel is 4 orders of magnitude faster than a clamshell mechanism, in which the substrate-enclosing loops open and release the substrate without reversing. We also present the crystal structure of a disulfide variant that covalently links substrate-enclosing loops on either side of the substrate-binding tunnel, which constitutes a CBH that can only dissociate via stepwise dethreading. Biochemical measurements indicate that this variant has a dissociation rate constant essentially equivalent to the wild type, implying that dethreading is likely the predominant mechanism for dissociation.
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21

Dresler, Ewa, Aneta Wróblewska, and Radomir Jasiński. "Understanding the Molecular Mechanism of Thermal and LA-Catalysed Diels–Alder Reactions between Cyclopentadiene and Isopropyl 3-Nitroprop-2-Enate." Molecules 28, no. 14 (2023): 5289. http://dx.doi.org/10.3390/molecules28145289.

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The molecular mechanism of the Diels–Alder reaction with the participation of cyclopentadiene and isopropyl 3-nitroprop-2-enate was examined based on wb97xd/6-311+G(d) (PCM) quantum chemical calculations. It was found that the type of mechanism for the conversion of addends depends significantly on the reaction conditions. In less-polar environments, a one-step polar mechanism is realised. In more polar solvents, the formation of “extended”-type zwitterionic intermediates is possible. In contrast, in the presence of an LA-type catalyst, the one-step mechanisms are replaced by respective stepwise mechanisms with zwitterionic or heterocyclic intermediates.
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22

Yang, Robin C. K., Jonathan T. B. Huang, Yu-Ling Chen, et al. "Enthalpy-driven nuclease-like activity and mechanism of peptide–chlorambucil conjugates." Org. Biomol. Chem. 12, no. 27 (2014): 4890–904. http://dx.doi.org/10.1039/c4ob00123k.

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23

Bachrach, Steven M., and John C. Gilbert. "The Reaction of Cyclopentyne with Ethene: Concerted vs Stepwise Mechanism?" Journal of Organic Chemistry 69, no. 19 (2004): 6357–64. http://dx.doi.org/10.1021/jo0492970.

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24

Gaweska, Helena M., Kenneth M. Roberts, and Paul F. Fitzpatrick. "Isotope Effects Suggest a Stepwise Mechanism for Berberine Bridge Enzyme." Biochemistry 51, no. 37 (2012): 7342–47. http://dx.doi.org/10.1021/bi300887m.

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25

Wang, Li, and Ming Wah Wong. "Mechanism of halogen-catalyzed Mukaiyama aldol reactions: concerted or stepwise?" Tetrahedron Letters 49, no. 24 (2008): 3916–20. http://dx.doi.org/10.1016/j.tetlet.2008.04.054.

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26

Heaps, Nicole A., and C. Dale Poulter. "Type-2 Isopentenyl Diphosphate Isomerase: Evidence for a Stepwise Mechanism." Journal of the American Chemical Society 133, no. 47 (2011): 19017–19. http://dx.doi.org/10.1021/ja208331q.

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27

Liu, Xiandong, and Evert Jan Meijer. "Mechanism of Base-Promoted Dehydrochlorination of Pentachloroethane: Concerted or Stepwise?" Journal of Physical Chemistry A 113, no. 15 (2009): 3542–44. http://dx.doi.org/10.1021/jp900944g.

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28

Göbel, Thomas, and K. Barry Sharpless. "Temperature Effects in Asymmetric Dihydroxylation: Evidence for a Stepwise Mechanism." Angewandte Chemie International Edition in English 32, no. 9 (1993): 1329–31. http://dx.doi.org/10.1002/anie.199313291.

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29

Rana, Nidhi, R. Jayaganthan, and Satya Prakash. "Stepwise Oxidation Mechanism of HVOF Sprayed NiCrAlY Coatings in Air." Transactions of the Indian Institute of Metals 67, no. 3 (2013): 393–400. http://dx.doi.org/10.1007/s12666-013-0362-7.

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30

Fawell, P., J. Avraamides, and G. Hefter. "Reduction of Vicinal Dihalides. I. The Electrochemical Reduction of meso and (±)-1,2-Dibromo-1,2-diphenylethane." Australian Journal of Chemistry 43, no. 8 (1990): 1421. http://dx.doi.org/10.1071/ch9901421.

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The mechanism of the electrochemical dehalogenation of organic vicinal dihalides has been examined in acetonitrile by using meso- and (�)-1,2-dibromo-1,2-diphenylethane. Reduction potentials and product distributions obtained from the isomeric dibromides could not be accommodated within a mechanism involving a concerted addition of two electrons. However, these results can be explained by a stepwise addition of electrons, allowing the possibility of bond rotation at an intermediate stage. The product distributions obtained from the reduction of the (�)- dibromide were found to be potential-dependent, a result not previously observed for this compound, but consistent with a stepwise mechanism.
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31

Tanwar, Arvin Sain, Niranjan Meher, Laxmi Raman Adil, and Parameswar Krishnan Iyer. "Stepwise elucidation of fluorescence based sensing mechanisms considering picric acid as a model analyte." Analyst 145, no. 14 (2020): 4753–67. http://dx.doi.org/10.1039/d0an00732c.

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The precise study of fluorescence-based sensing mechanisms and a step-by-step design experiment for the elucidation of the mechanism of sensing for newly designed sensing systems can be ascertained using the presented tutorial review.
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32

Bung, Navneet, Arijit Roy, U. Deva Priyakumar, and Gopalakrishnan Bulusu. "Computational modeling of the catalytic mechanism of hydroxymethylbilane synthase." Physical Chemistry Chemical Physics 21, no. 15 (2019): 7932–40. http://dx.doi.org/10.1039/c9cp00196d.

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Hydroxymethylbilane synthase (HMBS), the third enzyme in the heme biosynthesis pathway, catalyzes the formation of 1-hydroxymethylbilane (HMB) by a stepwise polymerization of four molecules of porphobilinogen (PBG) using the dipyrromethane (DPM) cofactor.
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33

Wang, Meng, Wanjian Ding, and Dongqi Wang. "Binding mechanism of uranyl to transferrin implicated by density functional theory study." RSC Advances 7, no. 7 (2017): 3667–75. http://dx.doi.org/10.1039/c6ra26109d.

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34

Kudinov, V. V., I. K. Krylov, and N. V. Korneeva. "Impact action on fiber and composite material based on it." Physics and Chemistry of Materials Treatment 6 (2020): 69–74. http://dx.doi.org/10.30791/0015-3214-2020-6-69-74.

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The low-velosity impact properties and failure mechanisms of ultra-high molecular weight polyethylene (UHMWPE) fiber (Dyneema®SK-75) and a composite material (CM) based on it with the rigid and flexible matrices were investigated by the “Impact Break” (IB) method. A fundamental difference in deformation behavior and failure mechanisms upon impact on the UHMWPE-fiber and on the CM based on this fiber has been investigated experimentally. It is shown that impact has a little effect on the properties of UHMWPE-fiber, since it is an isotropic material. It has been established that upon impact, the properties of a fiber without a matrix were significantly higher than the properties of CM based on it. Impact action stimulates the interaction between CM components (fibers and matrix). Mechanism of stepwise deformation of anisotropic CM is occurred, which begins from the first moment of impact and ends with the destruction of the CM. A “stairway of deformation” behavior is observed in anisotropic materials. Stepwise deformation is the main form of deformation and the basic mechanism of failure of anisotropic composite materials upon impact.
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35

Kroeger, Asja A., and Amir Karton. "A Computational Investigation of the Uncatalysed and Water-Catalysed Acyl Rearrangements in Ingenol Esters." Australian Journal of Chemistry 71, no. 4 (2018): 212. http://dx.doi.org/10.1071/ch17501.

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Ingenol esters have been identified as potent anticancer and HIV latency reversing agents. Ingenol-3-angelate was recently approved as a topical treatment for precancerous actinic keratosis skin lesions. It was found, however, that ingenol esters can undergo a series of acyl rearrangements, which may affect their biological potency and the shelf-life of drug formulations. We use double-hybrid density functional theory to explore the mechanisms for the uncatalysed and water-catalysed acyl migrations in a model ingenol ester. The uncatalysed reaction may proceed either via a concerted mechanism or via a stepwise mechanism that involves a chiral orthoester intermediate. We find that the stepwise pathway is kinetically preferred by a significant amount of ΔΔH‡298 = 44.5 kJ mol−1. The uncatalysed 3-O-acyl to 5-O-acyl and 5-O-acyl to 20-O-acyl stepwise rearrangements involve cyclisation and ring-opening steps, both concomitant with a proton transfer. We find that the ring-opening step is the rate-determining step for both rearrangements, with reaction barrier heights of ΔH‡298 = 251.6 and 177.1 kJ mol−1 respectively. The proton transfers in the cyclisation and ring-opening steps may be catalysed by a water molecule. The water catalyst reduces the reaction barrier heights of these steps by over 90 kJ mol−1.
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36

Protsenko, V. S. "Kinetics and Mechanism of Electrochemical Reactions Occurring during the Chromium Electrodeposition from Electrolytes Based on Cr(III) Compounds: A Literature Review." Reactions 4, no. 3 (2023): 398–419. http://dx.doi.org/10.3390/reactions4030024.

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A literature review was conducted to examine the current understanding of the kinetics and mechanism of electrochemical reactions occurring during the electrodeposition of chromium coatings from electrolytes based on trivalent chromium compounds. The research in this scientific field is crucial, as it addresses the pressing need for an alternative to chromium plating processes that rely on solutions containing highly toxic and harmful hexavalent chromium compounds. Numerous literature data on the kinetics and mechanism of the stepwise reduction process of Cr(III) complex ions were analyzed. The influence of various additives and surfactants on the reaction kinetics of the stepwise reduction of trivalent chromium ions was considered. Special attention was given to the kinetics of the stepwise discharge of trivalent chromium ions in ionic liquids and deep eutectic solvents.
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37

Mikołajczyk, Marian, Marek Cypryk, Bartłomiej Gostyński, and Jakub Kowalczewski. "Nucleophilic Substitution at Heteroatoms—Identity Substitution Reactions at Phosphorus and Sulfur Centers: Do They Proceed in a Concerted (SN2) or Stepwise (A–E) Way?" Molecules 27, no. 3 (2022): 599. http://dx.doi.org/10.3390/molecules27030599.

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The mechanisms of three selected identity substitution reactions at phosphorus and sulfur occurring with stereospecific inversion have been investigated using density functional theory (DFT). The first identity reaction between methoxyl anion and methyl ethylphenylphosphinate 1 reported in 1963 has been shown to proceed in a stepwise fashion according to the addition–elimination (A–E) mechanism involving formation of a pentacoordinate phosphorus intermediate (TBI-1). In contrast, the results of DFT studies of the identity chloride exchange reaction in (ethoxy)ethylphosphonochloridothionate 3 in acetone solution provided evidence that it proceeds synchronously according to the classical Ingold’s SN2-P mechanism. DFT calculations of the methoxyl–methoxy exchange reaction at sulfur in methyl p-toluenesulfinate 4 catalyzed by trifluoroacetic acid in methanol revealed that it proceeds stepwise (A–E mechanism), involving the formation of the high-coordinate sulfurane intermediate. In both identity transesterification reactions, 1 and 4, the transiently formed trigonal bipyramidal intermediates with the two methoxyl groups occupying apical positions (TBI-1 and TBI-4) have higher free energy barriers for the Berry-type pseudorotation than those for direct decomposition to starting phosphinate and sulfinate ensuring stereospecific inversion of configuration at the phosphinyl and sulfinyl centers. Thus, the DFT method proved its usefulness in the distinction between both mechanisms that are often indistinguishable by kinetic measurements.
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38

Fawell, P., J. Avraamides, and G. Hefter. "Reduction of Vicinal Dihalides. II. Leaving Group Effects on the Electrochemical Reduction of 1,2-Dihalo-1,2-diphenylethanes and 1,2-Dihalocyclohexanes." Australian Journal of Chemistry 44, no. 6 (1991): 791. http://dx.doi.org/10.1071/ch9910791.

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Leaving group effects on the electrochemical dehalogenation of organic vicinal dihalides have been examined in acetonitrile for the 1,2-dihalo-1,2-diphenylethanes and trans-1,2-dihalo-cyclohexanes. Reduction potentials and product distributions support a stepwise addition of two electrons, as previously proposed for the isomers of 1,2-dibromo-1,2-diphenylethane. A general reduction mechanism for the vicinal dihalides is proposed. Literature data for the electrochemical reduction of the 5,6-dihalodecanes, previously thought to favour a concerted two-electron mechanism, may be explained in terms of a stepwise process.
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39

Liu, Qian, Long-Jiu Cheng, and Kun Wang. "A theoretical study of an electronically mismatched Diels–Alder cycloaddition." RSC Advances 7, no. 49 (2017): 30618–25. http://dx.doi.org/10.1039/c7ra04480a.

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40

Chen, Jiahe, and Jinfeng Zhao. "Theoretical uncovering of the chalcogen element regulated ESDPT behaviors for 2,5-bis(2-benzoxazolyl)-hydroquinone derivatives." RSC Advances 14, no. 36 (2024): 26133–41. http://dx.doi.org/10.1039/d4ra03443k.

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41

Lotz, Alex, Juan F. Inglés-Romero, Dennis Stampfer, Matthias Lutz, Cristina Vicente-Chicote, and Christian Schlegel. "Towards a Stepwise Variability Management Process for Complex Systems." International Journal of Information System Modeling and Design 5, no. 3 (2014): 55–74. http://dx.doi.org/10.4018/ijismd.2014070103.

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Complex systems are executed in environments with a huge number of potential situations and contingencies, therefore a mechanism is required to express dynamic variability at design-time that can be efficiently resolved in the application at run-time based on the then available information. We present an approach for dynamic variability modeling and its exploitation at run-time. It supports different developer roles and allows the separation of two different kinds of dynamic variability at design-time: (i) variability related to the system operation, and (ii) variability associated with QoS. The former provides robustness to contingencies, maintaining a high success rate in task fulfillment. The latter focuses on the quality of the application execution (defined in terms of non-functional properties like safety or task efficiency) under changing situations and limited resources. The authors also discuss different alternatives for the run-time integration of the two variability management mechanisms, and show real-world robotic examples to illustrate them.
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42

Mustafa, Seham MD, and Olav Thulesius. "Cooling is a potent vasodilator of deep vessels in the rat." Canadian Journal of Physiology and Pharmacology 79, no. 11 (2001): 899–904. http://dx.doi.org/10.1139/y01-073.

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The objectives of this study were to determine the effect of cooling on smooth muscle tone of the pulmonary artery and aorta and to clarify the basic mechanism of these responses. We recorded isometric tension in smooth muscle strips of rat pulmonary artery and aorta in organ baths during stepwise cooling. Cooling responses were tested before and after the addition of various standard agents that interfere with known neurogenic (autonomic blockers, tetrodotoxin) and myogenic mechanisms (calcium channel blockers) of relaxation. We also examined the hypothesis of the presence of a cooling-released substance. Stepwise cooling (37°C to 4°C) of aortic smooth muscle induced reproducible graded relaxations that were inversely proportional to temperature. Cooling-induced relaxation was not dependent on a neural mechanism nor the release of neurotransmitters or a cooling-released substance such as NO or CO. Cooling of pulmonary arterial and aortic smooth muscle preparations induced a graded myogenic relaxation inversely proportional to the cooling temperature. The mechanism is not dependent on local nervous or known mediators but related to a direct physico-chemical effect of cooling.Key words: cooling, vasodilatation, pulmonary artery, aorta.
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43

V., Jagannadham. "Substituent effects on the spontaneous cleavage of α-methylbenzylgem- dichlorides in aqueous solution". Journal of Indian Chemical Society Vol. 82, Aug 2005 (2005): 759–60. https://doi.org/10.5281/zenodo.5830280.

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Department of Chemistry, Osmania University, Hyderabad-500 007, India <em>E-mail</em> jagannadham1950@yahoo.com <em>Manuscript received 1 September 2004, revised 8 March 2005, accepted 6 May 2005</em> The solvolysis reactions of &alpha;-methylbenzyl-gem-dichlorides in water proceed by a stepwise mechanism through a-chloro-&alpha;-methylbenzyl carbocation intermediates, which are captured by water with a rate constant k<sub>s</sub>/s to give the corresponding acetophenones as the sole detectable products.&nbsp;
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Nakahara, Kazuhide, Koki Yamaguchi, and Hisao Kansui. "Stepwise Reactions between Cyclic 1,4-Diazadienes and Ketenes: Characteristics and Mechanism." HETEROCYCLES 102, no. 3 (2021): 534. http://dx.doi.org/10.3987/com-20-14401.

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Yamamoto, Hiroshi, Naoki Wakamiya, and Masayuki Murata. "An Inter-Networking Mechanism with Stepwise Synchronization for Wireless Sensor Networks." Sensors 11, no. 9 (2011): 8241–60. http://dx.doi.org/10.3390/s110908241.

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Chiou, Jau-Yu, Ru-Siou Hsu, Chih-Wei Chiu, and Jiang-Jen Lin. "A stepwise mechanism for intercalating hydrophobic organics into multilayered clay nanostructures." RSC Advances 3, no. 31 (2013): 12847. http://dx.doi.org/10.1039/c3ra42037j.

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Majumdar, Chirabrata, Cy A. Stein, Jack S. Cohen, Samuel Broder, and Samuel H. Wilson. "Stepwise mechanism of HIV reverse transcriptase: primer function of phosphorothioate oligodeoxynucleotide." Biochemistry 28, no. 3 (1989): 1340–46. http://dx.doi.org/10.1021/bi00429a060.

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Wang, Tao, Dawen Niu, and Thomas R. Hoye. "The Hexadehydro-Diels–Alder Cycloisomerization Reaction Proceeds by a Stepwise Mechanism." Journal of the American Chemical Society 138, no. 25 (2016): 7832–35. http://dx.doi.org/10.1021/jacs.6b03786.

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Keller, B. K., M. D. Wojcik, and T. R. Fletcher. "A directly-dissociative stepwise reaction mechanism for gas-phase peroxyacetic acid." Journal of Photochemistry and Photobiology A: Chemistry 195, no. 1 (2008): 10–22. http://dx.doi.org/10.1016/j.jphotochem.2007.09.001.

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Oleinik, E. F., S. N. Rudnev, and O. B. Salamatina. "Stepwise mechanism of the nucleation of plastic deformation in glassy polymers." Doklady Physical Chemistry 465, no. 1 (2015): 259–62. http://dx.doi.org/10.1134/s0012501615110020.

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