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Journal articles on the topic 'Mechanism of Cyclization'

Author: Grafiati

Published: 5 June 2025

Last updated: 1 August 2025

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1

Macháček, Vladimír, Gabriela Svobodová, and Vojeslav Štěrba. "Kinetics and mechanism of base-catalyzed cyclization of substituted amides and nitriles of hydantoic acid." Collection of Czechoslovak Chemical Communications 52, no. 1 (1987): 140–55. http://dx.doi.org/10.1135/cccc19870140.

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Rates of base-catalyzed cyclizations of 8 substituted derivatives of hydantoic acid amide type R3-NH(5)-CO(4)-NR2(3)-CH2(2)-CO(1)-NHR1 and 9 nitriles type R3-NH(5)-CO(4)-NR2(3)-CHR1(2)-CN have been measured in aqueous and methanolic media. The cyclization of the amides in aqueous medium is also accompanied by hydrolysis of the hydantoins formed. In some cases the hydrolysis rate constant is greater than the corresponding cyclization reaction rate constant. With the least reactive amides, the cyclization is also accompanied by hydrolysis of the amide group. The rate of the cyclization reactions

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2

Guosheng Wang, Guosheng Wang, and Siyu Han and Ronghui Xu Siyu Han and Ronghui Xu. "The Ring Formation Mechanism in Cyclization of Berberine." Journal of the chemical society of pakistan 43, no. 3 (2021): 308. http://dx.doi.org/10.52568/000578/jcsp/43.03.2021.

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Berberine hydrochloride is a natural alkaloid with significant antitumor activities against many types of cancer cells, can be synthesized by cyclic reaction with hydrochloride condensate and glyoxal as raw materials and copper chloride as catalyst. In this study, the transition and energy change for the each reaction step was calculated by the density functional theory program Dmol3 in Materials Studio 2017. and the results testified that there are two ring formation in the cycliztion process, and according to the result we proposed the mechanism of this cyclization reaction. We also use infr

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3

Guosheng Wang, Guosheng Wang, and Siyu Han and Ronghui Xu Siyu Han and Ronghui Xu. "The Ring Formation Mechanism in Cyclization of Berberine." Journal of the chemical society of pakistan 43, no. 3 (2021): 308. http://dx.doi.org/10.52568/000578.

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Berberine hydrochloride is a natural alkaloid with significant antitumor activities against many types of cancer cells, can be synthesized by cyclic reaction with hydrochloride condensate and glyoxal as raw materials and copper chloride as catalyst. In this study, the transition and energy change for the each reaction step was calculated by the density functional theory program Dmol3 in Materials Studio 2017. and the results testified that there are two ring formation in the cycliztion process, and according to the result we proposed the mechanism of this cyclization reaction. We also use infr

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4

Reissig, Hans-Ulrich, and Reinhold Zimmer. "Cyclizations of Alkoxyallenes: Mechanisms, Intermediates, Products – A Personal Account on Solved and Unsolved Problems with Unique Allene Building Blocks." Synthesis 49, no. 15 (2017): 3291–302. http://dx.doi.org/10.1055/s-0036-1588846.

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The additions of lithiated alkoxyallenes to electrophiles, such as carbonyl compounds, thioketones, imines, and nitrones, provide the expected primary addition products. These alkoxyallene intermediates undergo ring-closure reactions under quite different conditions. Whereas allenyl hydroxylamine derivatives spontaneously cyclize to 1,2-oxazine derivatives, the related allenyl amines, thiols, and alcohols require, with distinct exceptions, promotion by acids, base, silver(I), or gold(I). The different mechanisms of these processes are discussed in this account. The serendipitous discovery of a

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5

Butt, Smaher E., Konrad Kepski, Jean-Marc Sotiropoulos, and Wesley J. Moran. "Hypervalent iodine-mediated cyclization of bishomoallylamides to prolinols." Beilstein Journal of Organic Chemistry 20 (September 30, 2024): 2455–60. http://dx.doi.org/10.3762/bjoc.20.209.

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A change in mechanism was observed in the hypervalent iodine-mediated cyclization of N-alkenylamides when the carbon chain between the alkene and the amide increased from two to three atoms. In the latter case, cyclization at the amide nitrogen to form the pyrrolidine ring was favored over cyclization at the amide oxygen. A DFT study was undertaken to rationalize the change in mechanism of this cyclization process. In addition, reaction conditions were developed, and the scope of this cyclization studied.

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6

Chen, Nanhao, Shenglong Wang, Lidia Smentek, B. Andes Hess, and Ruibo Wu. "Biosynthetic Mechanism of Lanosterol: Cyclization." Angewandte Chemie International Edition 54, no. 30 (2015): 8693–96. http://dx.doi.org/10.1002/anie.201501986.

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7

Chen, Nanhao, Shenglong Wang, Lidia Smentek, B. Andes Hess, and Ruibo Wu. "Biosynthetic Mechanism of Lanosterol: Cyclization." Angewandte Chemie 127, no. 30 (2015): 8817–20. http://dx.doi.org/10.1002/ange.201501986.

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8

Pytela, Oldřich, and Zdeněk Bahník. "Synthesis, kinetics and mechanism of cyclization of 1-(2-aryloxycarbonylphenyl)-3-phenyltriazenes." Collection of Czechoslovak Chemical Communications 55, no. 11 (1990): 2692–700. http://dx.doi.org/10.1135/cccc19902692.

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Twelve substituted 1-(2-aryloxycarbonylphenyl)-3-phenyltriazenes have been synthetized and kinetics of their reactions have been measured in 52.1% (by mass) aqueous methanol at pH 3 to 11. Plots of kobs vs pH show three regions: noncatalyzed cyclization (pH 4 to 7), acid-catalyzed splitting of the triazene chain, and base-catalyzed cyclization. The non-catalyzed cyclization exhibits a kinetic isotope effect, the reaction constant ρ = 2.69 (σ-p), and β1g = 1.02, which indicates a mechanism of E1cB type with intramolecular proton transfer and a transient formation of a ketene intermediate. The b

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9

Deng, Danfeng, Dayun Huang, Xiangyu Sun, and Biwen Gao. "Recent Advances in the Tandem Difunctionalization of Alkynes: Mechanism-Based Classification." Synthesis 53, no. 19 (2021): 3522–34. http://dx.doi.org/10.1055/a-1486-2158.

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AbstractRecent advances on the tandem difunctionalization of alkynes in the last decade (2010–2020) are summarized into five categories based on the type of mechanism: (1) radical addition and coupling for the synthesis of polysubstituted ketones and alkenes, (2) electrophilic addition of alkynes, (3) reactions mediated by haloalkynes or copper acetylides, (4) the preparation of cyclic compounds via radical processes, palladium-catalyzed reactions or conjugate additions, and (5) cyclic compounds as intermediates in ring openings. Herein, radical, electrophilic and nucleophilic reactions are di

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10

Pinta, Violaine, Martine Picaud, Françoise Reiss-Husson, and Chantal Astier. "Rubrivivax gelatinosus acsF (Previously orf358) Codes for a Conserved, Putative Binuclear-Iron-Cluster-Containing Protein Involved in Aerobic Oxidative Cyclization of Mg-Protoporphyrin IX Monomethylester." Journal of Bacteriology 184, no. 3 (2002): 746–53. http://dx.doi.org/10.1128/jb.184.3.746-753.2002.

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ABSTRACT This study describes the characterization of orf358, an open reading frame of previously unidentified function, in the purple bacterium Rubrivivax gelatinosus. A strain in which orf358 was disrupted exhibited a phenotype similar to the wild type under photosynthesis or low-aeration respiratory growth conditions. In contrast, under highly aerated respiratory growth conditions, the wild type still produced bacteriochlorophyll a (Bchl a), while the disrupted strain accumulated a compound that had the same absorption and fluorescence emission spectra as Mg-protoporphyrin but was less pola

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11

Deng, Zhiqiang, Lu Jin, Yong Wu, and Xiang Zhao. "Mechanistic investigation on radical-induced construction of oxindoles: radical versus electrophilic cyclization." RSC Advances 7, no. 49 (2017): 30984–89. http://dx.doi.org/10.1039/c7ra04756h.

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12

Shigehisa, Hiroki. "Cyclization Reaction by MHAT/RPC Mechanism." Journal of Synthetic Organic Chemistry, Japan 82, no. 9 (2024): 890–901. http://dx.doi.org/10.5059/yukigoseikyokaishi.82.890.

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13

Kende, Andrew S., Olivier Henry, and Zecheng Chen. "Mechanism of an unusual decarboxylative cyclization." Tetrahedron Letters 45, no. 41 (2004): 7809–12. http://dx.doi.org/10.1016/j.tetlet.2004.05.161.

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14

Kaválek, Jaromír, Vladimír Macháček, Gabriela Svobodová, and Vojeslav Štěrba. "Kinetics and mechanism of reversible, base-catalyzed ring closure of 3-(methoxycarbonyl)propionanilide and O-(methoxycarbonylmethyl)-N-phenylcarbamate." Collection of Czechoslovak Chemical Communications 54, no. 4 (1989): 1005–11. http://dx.doi.org/10.1135/cccc19891005.

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The rate constants of reversible, base-catalyzed ring closure of 3-(methoxycarbonyl)propionanilide (I) and O-(methoxycarbonylmethyl)-N-phenylcarbamate (II) to 1-phenyl-2,5-pyrrolidinedione (III) and 3-phenyl-2,4-oxazolidinedione (IV), respectively, and the rates of solvolyses of the cyclization products III and IV in water and methanol have been measured. In both cases, an equilibrium is established between the starting ester and the cyclization product in methoxide solutions which is strongly shifted in favour of the starting ester. In the case of ester II in methoxide solutions, the cyclizat

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15

Qiu, Rongxiang. "Applications of transition state calculations in the key cyclization of small molecule natural product synthesis." E3S Web of Conferences 290 (2021): 01024. http://dx.doi.org/10.1051/e3sconf/202129001024.

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The diversification of the conformation and configuration of the carbocyclic skeleton of natural products is an important reason for the diversity and complexity of the structure of natural products. The corresponding cyclization synthesis has attracted much attention. Computational chemistry approaches have the advantages of non-toxic, harmless and relatively low cost, and they are increasingly used to model and understand molecular phenomena. The reaction mechanism and thermodynamic parameters determine the feasibility of the cyclization and the enantioselectivity of the cyclization products

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16

Šmit, Biljana M., Radoslav Z. Pavlović, Dejan A. Milenković, and Zoran S. Marković. "Mechanism, kinetics and selectivity of selenocyclization of 5-alkenylhydantoins: an experimental and computational study." Beilstein Journal of Organic Chemistry 11 (October 7, 2015): 1865–75. http://dx.doi.org/10.3762/bjoc.11.200.

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The mechanism and selectivity of a bicyclic hydantoin formation by selenium-induced cyclization are investigated. The proposed mechanism involves the intermediates formed by an electrophilic addition of the selenium reagent on a double bond of the starting 5-alkenylhydantoin prior the cyclization. These intermediates are readily converted into the more stable cyclic seleniranium cations. A key step of the mechanism is an intramolecular cyclization which is realized through an anti-attack of the internal nucleophile, the amidic nitrogen, to the seleniranium cation yielding the intermediate imid

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17

Ludwig, Miroslav, and Ingrid Bauerová. "Steric Effects in the Base-Catalyzed Cyclization of 1-[2-(Methoxycarbonyl)phenyl]-3-(2-substituted Phenyl)triazenes." Collection of Czechoslovak Chemical Communications 63, no. 12 (1998): 2075–84. http://dx.doi.org/10.1135/cccc19982075.

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Eleven model 1-[2-(methoxycarbonyl)phenyl]-3-(2-substituted phenyl)triazenes were synthesized and their cyclization kinetics examined in aqueous-methanolic buffer solutions (51 wt.% methanol) at various pH values. 3(2-Substituted phenyl)benzo[d][1,2,3]triazin-4(3H)-ones were identified as the cyclization products. The log kobs vs pH plot was linear with a slope of unity. Investigation of the steric and electronic effects of substituents in the ortho position revealed that substituents at the ring which is bonded to the N(3) nitrogen affect the cyclization rate through their steric effect only,

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18

Yuan, Lang, and Hai-Tao Yu. "A Density Functional Theory Investigation of the Tandem Radical Cyclization of 1-[2-Yl-3-(2-Methoxyphenyl)-prop-2-enyl]-6-oxo-1,6-dihydropyridine-2-carbonitrile." Australian Journal of Chemistry 69, no. 3 (2016): 319. http://dx.doi.org/10.1071/ch15369.

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A density functional theory investigation of the mechanism of the titled reaction has been performed. The results suggest that the compound 1-[2-iodo-3-(2-methoxyphenyl)-prop-2-enyl]-6-oxo-1,6-dihydropyridine-2-carbonitrile would rather be converted into the titled free radical by deiodination than go by way of a Diels–Alder cycloaddition and HI-elimination to access the experimentally observed product. The deiodination of the radical precursor is followed by tandem radical cyclizations and hydrogen-loss oxidations to generate tetracyclic non-radical products. The mechanism of the tandem react

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19

Godfrey, Jollie D., Richard H. Mueller та Derek J. Von Langen. "β-Lactam synthesis: Cyclization versus 1,2-acyl migration-cyclization. The mechanism of the 1,2-acyl migration-cyclization". Tetrahedron Letters 27, № 25 (1986): 2793–96. http://dx.doi.org/10.1016/s0040-4039(00)84644-4.

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20

Zhou, Huan, Botao Wu, Jun-An Ma, and Yanfeng Dang. "Mechanistic understanding of [Rh(NHC)]-catalyzed intramolecular [5 + 2] cycloadditions of vinyloxiranes and vinylcyclopropanes with alkynes." Organic & Biomolecular Chemistry 16, no. 23 (2018): 4295–303. http://dx.doi.org/10.1039/c8ob01117f.

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Rh-catalyzed hetero-[5 + 2] cycloaddition of vinyloxirane with alkyne occurs via oxidative alkyne–alkene cyclization, oxirane cleavage and reductive elimination, the first example where oxidative alkyne–alkene cyclization mechanism is preferred within Rh-catalyzed [5 + 2] cycloadditions.

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21

Athelstan, L., and J. Beckwith. "Mechanism and applications of free radical cyclization." Reviews of Chemical Intermediates 7, no. 2 (1986): 143–54. http://dx.doi.org/10.1007/bf03155651.

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22

Haslak, Zeynep Pinar, Sesil Agopcan Cinar, Sevgi Sarigul Ozbek, Gérald Monard, Ilknur Dogan, and Viktorya Aviyente. "Elucidation of the atroposelectivity in the synthesis of axially chiral thiohydantoin derivatives." Organic & Biomolecular Chemistry 18, no. 12 (2020): 2233–41. http://dx.doi.org/10.1039/c9ob02556a.

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A DFT study is carried out in order to elucidate the racemization and cyclization mechanism as well as the atroposelectivity during the synthesis of 2-thiohydantoins. Computational data shows that the racemization occurs after cyclization with the assistance of triethyl amine.

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23

Toms, Roman V., Daniil A. Ismaylov, Alexander Yu Gervald, Nickolay I. Prokopov, Anna V. Plutalova, and Elena V. Chernikova. "In Situ Formation of Acidic Comonomer during Thermal Treatment of Copolymers of Acrylonitrile and Its Influence on the Cyclization Reaction." Polymers 16, no. 19 (2024): 2833. http://dx.doi.org/10.3390/polym16192833.

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Binary and ternary copolymers of acrylonitrile (AN), tert-butyl acrylate (TBA), and n-butyl acrylate (BA) are synthesized through conventional radical polymerization in DMSO in the presence of 2-mercaptoethanol. The thermal behavior of binary and ternary copolymers is studied under argon atmosphere and in air. It is demonstrated that the copolymers of AN contain 1–10 mol.% of TBA split isobutylene upon heating above 160 °C, resulting in the formation of the units of acrylic acid in the chain. The carboxylic groups formed in situ are responsible for the ionic mechanism of cyclization, which sta

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24

Ariyawutthiphan, Orapin, Toyoyuki Ose, Atsushi Minami, et al. "Structure analysis of geranyl pyrophosphate methyltransferase and the proposed reaction mechanism of SAM-dependentC-methylation." Acta Crystallographica Section D Biological Crystallography 68, no. 11 (2012): 1558–69. http://dx.doi.org/10.1107/s0907444912038486.

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In the typical isoprenoid-biosynthesis pathway, condensation of the universal C5-unit precursors isopentenyl pyrophosphate (IPP) and dimethylallyl pyrophosphate (DMAPP) occursviathe common intermediates prenyl pyrophosphates (C10–C20). The diversity of isoprenoids reflects differences in chain length, cyclization and further additional modification after cyclization. In contrast, the biosynthesis of 2-methylisonorneol (2-MIB), which is responsible for taste and odour problems in drinking water, is unique in that it primes the enzymatic methylation of geranyl pyrophosphate (GPP) before cyclizat

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25

Sedlák, Miloš, Jiří Hanusek, Radim Bína, Jaromír Kaválek, and Vladimír Macháček. "Kinetics and Mechanism of the Formation and Decomposition of Imidazolin-4-ones from 2-(N-Benzoylamino)alkanamides in Aqueous Medium." Collection of Czechoslovak Chemical Communications 64, no. 10 (1999): 1629–40. http://dx.doi.org/10.1135/cccc19991629.

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The cyclization reactions of substituted 2-(N-benzoyl-N-methyl)aminoalkanamides 1a-1g have been studied in aqueous medium. The Hammett reaction constant is ρ = 1.4 for the cyclization reactions of compounds 1a-1e in sodium hydroxide solutions. 2-[N-Methyl- N-(4-nitrobenzoyl)amino]-2-(4-nitrophenyl)propanamide (1g) is cyclized to imidazolinone 2g in aqueous amine buffers of pH 9-11.5; the reaction is subject to specific base catalysis in these media, and the rate-limiting step is the formation of a tetrahedral intermediate. In sodium hydroxide solution, the primary cyclization product is hydrol

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26

Méndez-Hurtado, Jefferson, M. Isabel Menéndez, Ramón López, and Manuel F. Ruiz-López. "Unraveling the intramolecular cyclization mechanism of oxidized tryptophan in aqueous solution as a function of pH." Organic & Biomolecular Chemistry 13, no. 32 (2015): 8695–702. http://dx.doi.org/10.1039/c5ob01193k.

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27

Jankowiak, Aleksandra, Emilia Obijalska, and Piotr Kaszynski. "Cyclization of substitued 2-(2-fluorophenylazo)azines to azino[1,2-c]benzo[d][1,2,4]triazinium derivatives." Beilstein Journal of Organic Chemistry 9 (September 16, 2013): 1873–80. http://dx.doi.org/10.3762/bjoc.9.219.

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Light-induced cyclization of several substituted 2-(2-fluorophenylazo)azines in the presence of Ca2+ ions to the corresponding triazinium derivatives is investigated experimentally and computationally. The azo derivatives of 4-methylpyridine 4 undergo facile cyclization to the corresponding triazinium 1, and the rate of cyclization increases with increasing number of fluorine atoms at the benzene ring. No triazinium ions were obtained from azo derivatives of 4-cyanopyridine, pyrazine and pyrimidine, presumably due to their instability under the reaction conditions. The experimental results and

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28

Liu, Jian-Biao, Xin Zhang, Ying-Ying Tian, Xin Wang, Xun-Kun Zhu, and De-Zhan Chen. "Mechanism and origins of ligand-controlled Pd(ii)-catalyzed regiodivergent carbonylation of alkynes." Dalton Transactions 48, no. 40 (2019): 15059–67. http://dx.doi.org/10.1039/c9dt03294k.

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29

Cabrera-Lobera, Natalia, M. Teresa Quirós, Elena Buñuel, and Diego J. Cárdenas. "Atom-economical regioselective Ni-catalyzed hydroborylative cyclization of enynes: development and mechanism." Catalysis Science & Technology 9, no. 4 (2019): 1021–29. http://dx.doi.org/10.1039/c8cy02568a.

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30

López, Carlos Silva, Olalla Nieto Faza, Ken S. Feldman, Malliga R. Iyer, and D. Keith Hester. "Cyclization Cascade of Allenyl Azides: A Dual Mechanism." Journal of the American Chemical Society 129, no. 24 (2007): 7638–46. http://dx.doi.org/10.1021/ja070818l.

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31

Harding, Charles E., and G. Richard Stanford. "Mechanism of the transannular cyclization of 5-cyclodecynone." Journal of Organic Chemistry 54, no. 13 (1989): 3054–56. http://dx.doi.org/10.1021/jo00274a018.

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32

Huang, Genping. "Mechanism of Rhodium-Catalyzed Cyclopropanation/Cyclization of Allenynes." Organic Letters 17, no. 8 (2015): 1994–97. http://dx.doi.org/10.1021/acs.orglett.5b00753.

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33

Harding, Charles E., and Salane L. King. "Mechanism of the intramolecular cyclization of acetylenic ketones." Journal of Organic Chemistry 57, no. 3 (1992): 883–86. http://dx.doi.org/10.1021/jo00029a019.

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34

Xia, Ping, Chen Wang, and Chenze Qi. "Theoretical Study on the Cyclization Mechanism of Dipeptides." Chinese Journal of Chemistry 31, no. 6 (2013): 813–18. http://dx.doi.org/10.1002/cjoc.201300035.

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35

Saloutin, Victor I., Marina V. Goryaeva, Svetlana O. Kushch, et al. "Competitive ways for three-component cyclization of polyfluoroalkyl-3-oxo esters, methyl ketones and amino alcohols." Pure and Applied Chemistry 92, no. 8 (2020): 1265–75. http://dx.doi.org/10.1515/pac-2019-1216.

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AbstractThe competitive routes were found for three-component cyclization of polyfluoroalkyl-3-oxo esters, methyl ketones with 3-amino alcohols. It was shown that the reactions with 3-aminopropanol in 1,4-dioxane predominantly lead to hexahydropyrido[2,1-b][1,3]oxazin-6-ones, and in ethanol to 3-hydroxypropylaminocyclohexenones. In contrast, cyclizations with 2-aminoethanol and its analogues, regardless of the reaction conditions, yield hexahydrooxazolo[3,2-a]pyridin-5-ones as the main products. The trans- and cis-diastereomeric structure of heterocycles was established using X-ray and 1H, 19F

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36

Mindl, Jaromír, and Vojeslav Štěrba. "Mechanism of base-catalyzed cyclization of ethyl N-(substituted aminocarbonyl)glycinates." Collection of Czechoslovak Chemical Communications 52, no. 1 (1987): 156–61. http://dx.doi.org/10.1135/cccc19870156.

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The cyclization rate constants have been measured of substituted ethyl N-(phenylaminocarbonyl)-, N-(alkylaminocarbonyl)-, and N-(phenylaminothiocarbonyl)glycinates RNHCXNHCH2CO2.C2H5 (X = O, S). Logarithms of these constants increase with decreasing basicity of the amines down to the value of pKa(RNH2) = 5.5. The rate-limiting step of the reaction is formation of the tetrahedral intermediate. With ethyl N-(phenylaminocarbonyl)glycinates (whose pKa(RNH2) values are higher) this dependence, on the contrary, slightly decreases, and the acid-catalyzed splitting off of ethoxy group from the cyclic

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37

Artemjev, Alexey A., Alexander A. Sapronov, Alexey S. Kubasov та ін. "Diverse Cyclization Pathways Between Nitriles with Active α-Methylene Group and Ambiphilic 2-Pyridylselenyl Reagents Enabled by Reversible Covalent Bonding". International Journal of Molecular Sciences 25, № 23 (2024): 12798. http://dx.doi.org/10.3390/ijms252312798.

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Herein, we describe a novel coupling between ambiphilic 2-pyridylselenyl reagents and nitriles featuring an active α-methylene group. Depending on the solvent employed, this reaction can yield two distinct types of cationic pyridinium-fused selenium-containing heterocycles, 1,3-selenazolium or 1,2,4-selenadiazolium salts, in high yields. This is in contrast to what we observed before for other nitriles. Notably, the formation of selenadiazolium is reversible, gradually converting into the more thermodynamically stable selenazolium product in solution. Our findings reveal, for the first time, t

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38

Umek, Nejc. "Cyclization step of noradrenaline and adrenaline autoxidation: a quantum chemical study." RSC Advances 10, no. 28 (2020): 16650–58. http://dx.doi.org/10.1039/d0ra02713h.

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39

Gong, Julin, Kun Hu, Yetong Zhang, et al. "Efficient Tandem Addition/Cyclization for Access to 2,4-Diarylquinazolines via Catalytic Carbopalladation of Nitriles." Molecules 24, no. 3 (2019): 463. http://dx.doi.org/10.3390/molecules24030463.

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The first example of the palladium-catalyzed tandem addition/cyclization of 2-(benzylidenamino)benzonitriles with arylboronic acids has been developed. This transformation features good functional group tolerance and provides an alternative synthetic pathway to access 2,4-diarylquinazolines in moderate to good yields. A plausible mechanism for the formation of 2,4-diarylquinazolines involving sequential nucleophilic addition followed by an intramolecular cyclization is proposed.

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40

Wang, Rui-Xiang, Zhuang Fang, Guanyinsheng Qiu, Wenlin Xie, and Jin-Biao Liu. "Copper-Catalyzed 6-endo-dig O-Cyclization of 2-(But-3-en-1-yn-1-yl)benzamide." Synthesis 51, no. 21 (2019): 4048–65. http://dx.doi.org/10.1055/s-0039-1690155.

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The copper-catalyzed synthesis of 3-vinylisocoumarin-1-imine is reported. The transformation proceeds smoothly with good yields in THF and the regioselectivity was determined by a O-nucleophilic 6-endo cyclization. Studies on the mechanism indicate that copper trifluoroacetate serves as a Lewis acid, and the use of vinyl-connected 2-alkynylbenzamide is important for this O-nucleophilic 6-endo cyclization.

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41

Yahya, Amri, Dwiarso Rubiyanto, and Is Fatimah. "Heterogeneous Catalytic Conversion of Citronellal into Isopulegol and Menthol: Literature Review." Science and Technology Indonesia 6, no. 3 (2021): 166–80. http://dx.doi.org/10.26554/sti.2021.6.3.166-180.

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The conversion of citronellal into isopulegol is a key route in the production of a number of important chemicals. In the perspective of green conversion, the use of a heterogeneous catalyst is superior due to its ease in separation and reusability, so it facilitates a highly economical conversion. In this review, we examine the use of some transition metals in cyclization reactions, which are suitable for citronellal conversion into isopulegol, and consider the potential progress in clay-based catalysts. The structure of clay which potentially provides the porosity by modification and support

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Kaválek, Jaromír, Vladimír Macháček, Miloš Sedlák, and Vojeslav Štěrba. "Kinetics and mechanism of cyclization of N-(2-methoxycarbonylphenyl)-N’-methylsulphonamide to 3-methyl-(1H)-2,1,3-benzothiadiazin-4(3H)-one 2,2-dioxide." Collection of Czechoslovak Chemical Communications 56, no. 8 (1991): 1701–10. http://dx.doi.org/10.1135/cccc19911701.

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The cyclization kinetics of N-(2-methylcarbonylphenyl)-N’-methylsulfonamide (IIb) into 3-methyl-(1H)-2,1,3-benzothiadiazin-4(3H)-one 2,2-dioxide (Ib) has been studied in ethanolamine, morpholine, and butylamine buffers and in potassium hydroxide solution. The cyclization is subject to general base and general acid catalysis. The value of the Bronsted coefficient β is about 0.1, which indicates that splitting off of the proton from negatively charged tetrahedral intermediate represents the rate-limiting and thermodynamically favourable step. In the solutions of potassium hydroxide the cyclizati

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Zhen, Hecheng, Huiyun Yang, Mei Wang, Guosheng Lu, Yanfang Liu, and Mingtao Run. "Cyclo-oligomerization of hydroxyl-containing mono-functional benzoxazines: a mechanism for oligomer formation." Polymer Chemistry 11, no. 13 (2020): 2325–31. http://dx.doi.org/10.1039/d0py00047g.

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Gao, Liang, Rui Hu, Pengfei Xu, Jiaping Lin, Liangshun Zhang, and Liquan Wang. "Supramolecular cyclization of semiflexible cylindrical micelles assembled from rod-coil graft copolymers." Nanoscale 12, no. 1 (2020): 296–305. http://dx.doi.org/10.1039/c9nr07930k.

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Li, Yunhe, and Xiang Zhao. "Mechanism and origins of gold-catalyzed domino cyclization to spiroindolines: the role of periplanar cooperation and hydrogen bonding interactions." Organic Chemistry Frontiers 7, no. 13 (2020): 1663–70. http://dx.doi.org/10.1039/d0qo00359j.

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Siedenburg, Gabriele, Dieter Jendrossek, Michael Breuer, et al. "Activation-Independent Cyclization of Monoterpenoids." Applied and Environmental Microbiology 78, no. 4 (2011): 1055–62. http://dx.doi.org/10.1128/aem.07059-11.

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ABSTRACTThe biosynthesis of cyclic monoterpenes (C10) generally requires the cyclization of an activated linear precursor (geranyldiphosphate) by specific terpene cyclases. Cyclic triterpenes (C30), on the other hand, originate from the linear precursor squalene by the action of squalene-hopene cyclases (SHCs) or oxidosqualene cyclases (OSCs). Here, we report a novel terpene cyclase fromZymomonas mobilis(ZMO1548-Shc) with the unique capability to cyclize citronellal to isopulegol. To our knowledge, ZMO1548-Shc is the first biocatalyst with diphosphate-independent monoterpenoid cyclase activity

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Shi, Jing, Ying Jie Zeng, Bo Zhang, et al. "Comparative genome mining and heterologous expression of an orphan NRPS gene cluster direct the production of ashimides." Chemical Science 10, no. 10 (2019): 3042–48. http://dx.doi.org/10.1039/c8sc05670f.

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Toms, Roman V., Mikhail S. Balashov, Alexander Yu Gervald, Nikolay I. Prokopov, Anna V. Plutalova, and Elena V. Chernikova. "Influence of Monomer Sequence on the Cyclization Behavior of Poly(acrylonitrile-co-acrylamide)." Applied Sciences 13, no. 6 (2023): 3734. http://dx.doi.org/10.3390/app13063734.

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In this research, we have developed the approach to controlled synthesis of acrylonitrile-acrylamide copolymers with narrow molecular weight distribution and various monomer sequence distributions. By using dibenzyl trithiocarbonate and batch/semibatch polymerization, we have first synthesized random, gradient, and block-gradient copolymers containing 3.4–10.2 mol. % of acrylamide and revealed the influence of the monomer sequence on the cyclization behavior of poly(acrylonitrile-co-acrylamide) by combination of differential scanning calorimetry and Fourier transform infrared spectroscopy. Thi

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Pino-Gonzalez, M. S., A. Romero-Carrasco, S. Calvo-Losada, N. Oña-Bernal, J. J. Quirante, and F. Sarabia. "Synthesis of tetrazole fused azepanes and quantum chemical topology study on the mechanism of the intramolecular cycloaddition reaction." RSC Adv. 7, no. 79 (2017): 50367–71. http://dx.doi.org/10.1039/c7ra10899k.

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Zhao, Yang, Ping Wang, Yun Gao, Chen Zhu, Wei Liu, and Yong Wang. "Mechanistic insights into intermolecular cyclization of ring-fused benzocyclobutenols with alkynes catalyzed by [{Ir(OMe)COD}2]." Organic Chemistry Frontiers 6, no. 6 (2019): 791–95. http://dx.doi.org/10.1039/c8qo01371c.

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