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1. Bicyclic (alkyl)(amino)carbene stabilized zinc(0) complex with singlet biradicaloid ground state

Author:
Rajendran, N. M.; Gautam, Nimisha; Sarkar, Pallavi; Ahmed, Jasimuddin; Das, Arpan; Das, Shubhajit; Pati, Swapan K.; Mandal, Swadhin K.
Source:
Chemical communications 2021 v.57 no.43 pp. 5282-5285
ISSN:
1364-548X
Subject:
free radicals,   etc   ; carbenes; chlorides; zinc;     Show all 4 Subjects
Abstract:
... A storable bicyclic (alkyl)(amino)carbene (BICAAC) stabilized two coordinate zinc(0) complex [(BICAAC)₂Zn] (2) was synthesized. DFT calculations reveal that BICAAC plays a decisive role in imparting the stability to 2. This complex activates the C(sp3)–Cl bond of trityl chloride generating the Gomberg's free radical with greater efficiency than metallic Zn powder. ...
DOI:
10.1039/d1cc01298c

2. WS2 as highly active co-catalyst for the regeneration of Fe(II) in the advanced oxidation processes

Author:
Luo, Haopeng; Zhou, Xin; Guo, Xiaojie; Fang, Zhiyong; Chen, Quanyuan; Zhou, Juan
Source:
Chemosphere 2021 v.262 pp. 128067
ISSN:
0045-6535
Subject:
free radicals,   etc   ; humic acids; oxidation;     Show all 3 Subjects
Abstract:
... The greatest constraint in the advanced oxidation processes involved Fe(II)/PMS was the low utilization of Fe(II) and PMS. In the present study, the co-catalytic effect of WS₂ on the Fe(II)/PMS system for the degradation of organics was investigated. In the presence of WS₂, Fe(III) was reduced to Fe(II) during the reaction and resulted in improved decomposition of PMS as well as the degradation of ...
DOI:
10.1016/j.chemosphere.2020.128067

3. Novel transformation of aryl 2-iodophenyl ketones into 1,3-diarylisoquinolines with (TMS)2NH, styrenes, NIS, and tBuOK

Author:
Shibasaki, Kaho; Togo, Hideo
Source:
Tetrahedron 2021 v.79 pp. 131864
ISSN:
0040-4020
Subject:
free radicals,   etc   ; aromatization; ketimines; ketones; yields;     Show all 5 Subjects
Abstract:
... Treatment of aryl 2-iodophenyl ketones with TMS₂NH in the presence of Sc(OTf)₃ at warming conditions, followed by the reaction with styrenes and NIS gave N-(1-aryl-2-iodoethyl) aryl 2-iodophenyl ketimines. Further treatment of N-(1-aryl-2-iodoethyl) aryl 2-iodophenyl ketimines with ᵗBuOK in the presence of 1,10-phenanthroline at 120 °C generated 1,3-diarylisoquinolines in moderate yields through S ...
DOI:
10.1016/j.tet.2020.131864

4. Iron-promoted free radical cascade difunctionalization of unsaturated benzamides with silanes

Author:
Ge, Yaxin; Tian, Yunfei; Wu, Jilai; Yan, Qinqin; Zheng, Luping; Ren, Yingming; Zhao, Jincan; Li, Zejiang
Source:
Chemical communications 2020 v.56 no.83 pp. 12656-12659
ISSN:
1364-548X
Subject:
free radicals,   etc   ; benzamides; silanes;     Show all 3 Subjects
Abstract:
... Iron salt/peroxide promoted cascade difunctionalization of unsaturated benzamides with silanes has been reported. It provides a convenient, highly selective, and efficient protocol for the synthesis of various silylated dihydroisoquinolinones and 1,3-isoquinolinediones. In particular, the present methodology only gives cyclization products in good isolated yields under the typical conditions. ...
DOI:
10.1039/d0cc05213b

5. Studies on the preparation of aminobipyridines and bipyridine sultams via an intramolecular free radical pathway

Author:
Recio, Javier; Filace, Fabiana; Gala, Elena; Pérez-Redondo, Adrián; Álvarez-Builla, Julio; Burgos, Carolina
Source:
RSC advances 2020 v.10 no.18 pp. 10447-10451
ISSN:
2046-2069
Subject:
free radicals,   etc   ; pyridines;     Show all 2 Subject
Abstract:
... A variety of aminated bipyridines and bipyridine sultams are prepared by intramolecular radical [1,5]-ipso and [1,6]-ortho substitutions, using a sulfonamide as a linker to connect the pyridyl radical to the pyridine under attack. For the cases studied, different regiochemistries are observed depending on the initial position of the sulfonamide linker. ...
DOI:
10.1039/d0ra02026e

6. Cu2+/Cu+ cycle promoted PMS decomposition with the assistance of Mo for the degradation of organic pollutant

Author:
Zhou, Xin; Luo, Haopeng; Sheng, Bo; Chen, Xingyu; Wang, Yihao; Chen, Quanyuan; Zhou, Juan
Source:
Journal of hazardous materials 2021 v.411 pp. 125050
ISSN:
0304-3894
Subject:
free radicals,   etc   ; 2,4-dichlorophenol; humic acids; molybdenum; oxidation; pH; pollutants;     Show all 7 Subjects
Abstract:
... The limited production of Cu⁺ in the Cu²⁺/PMS processes constrained its large-scan application for the elimination of organic pollutants. In this study, molybdenum powder (Mo) was applied as the co-catalyst to improve the degradation of 2,4-dichlorophenol (2,4-DCP) in Cu²⁺/PMS system at pH 5.6. By the assistance of Mo, Cu²⁺ was rapidly reduced to Cu⁺ which exhibited super activity for the peroxymo ...
DOI:
10.1016/j.jhazmat.2021.125050

7. Visible light induced step-growth polymerization by electrophilic aromatic substitution reactions

Author:
Kiliclar, Huseyin Cem; Altinkok, Cagatay; Yilmaz, Gorkem; Yagci, Yusuf
Source:
Chemical communications 2021 v.57 no.44 pp. 5398-5401
ISSN:
1364-548X
Subject:
free radicals,   etc   ; Lewis acids; Lewis bases; composite polymers; fluorescence; polymerization;     Show all 6 Subjects
Abstract:
... A novel visible light induced step-growth polymerization to form poly(phenylene methylene) by electrophilic aromatic substitution reactions is described. The effect of different nucleophilic aromatic molecules on polymerization has been investigated. The possibility of combining step-growth polymerization with conventional free radical and free radical promoted cationic polymerizations through pho ...
DOI:
10.1039/d1cc01444g

8. Multicomponent Synthesis of α-Branched Tertiary and Secondary Amines by Photocatalytic Hydrogen Atom Transfer Strategy

Author:
Qi, Xu-Kuan; Guo, Lin; Yao, Li-Juan; Gao, Han; Yang, Chao; Xia, Wujiong
Source:
Organic letters 2021 v.23 no.11 pp. 4473-4477
ISSN:
1523-7052
Subject:
free radicals,   etc   ; amination; hydrogen; photocatalysis; photocatalysts; tetrabutylammonium compounds;     Show all 6 Subjects
Abstract:
... A multicomponent carbonyl alkylative amination reaction is described. A variety of N-arylamines, aldehydes, and hydrocarbons have been examined as reaction substrates using tetrabutylammonium decatungstate as photocatalyst, providing the corresponding α-branched tertiary and secondary amines in good to moderate yields. The reaction proceeds through the generation of alkyl radicals by a light-promo ...
DOI:
10.1021/acs.orglett.1c01412

9. Plant Nitric Oxide Signaling under Drought Stress

Author:
Lau, Su-Ee; Hamdan, Mohd Fadhli; Pua, Teen-Lee; Saidi, Noor Baity; Tan, Boon Chin
Source:
Plants 2021 v.10 no.2
ISSN:
2223-7747
Subject:
free radicals,   etc   ; drought; genetic engineering; metabolism; nitric oxide; water stress;     Show all 6 Subjects
Abstract:
... Water deficit caused by drought is a significant threat to crop growth and production. Nitric oxide (NO), a water- and lipid-soluble free radical, plays an important role in cytoprotection. Apart from a few studies supporting the role of NO in drought responses, little is known about this pivotal molecular amendment in the regulation of abiotic stress signaling. In this review, we highlight the kn ...
DOI:
10.3390/plants10020360

10. Fluorescence activation, patterning and enhancement with photogenerated radicals, a prefluorescent probe and silver nanostructures

Author:
Golian, Karol P.; Akari, Aviya S.; Hodgson, Gregory K.; Impellizzeri, Stefania
Source:
RSC advances 2021 v.11 no.9 pp. 5163-5171
ISSN:
2046-2069
Subject:
free radicals,   etc   ; dyes; fluorescence; lighting; moieties; polymers; silver;     Show all 7 Subjects
Abstract:
... We synthesized a dual fluorogenic system based on a boron-dipyrromethene (BODIPY) dye coupled with a paramagnetic 2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPO) nitroxide. Electron exchange facilitates the non-radiative relaxation of the singlet state of the chromophore, partially quenching the fluorescence from the BODIPY moiety. Nonetheless, the system can be ‘activated’ in solution or thin polyme ...
DOI:
10.1039/d0ra09565f

11. Rubber reclamation with high bond-breaking selectivity using a low-temperature mechano-chemical devulcanization method

Author:
Guo, Lei; Wang, Chuansheng; Lv, Dejun; Ren, Donghui; Zhai, Tianjian; Sun, Changlong; Liu, Haichao
Source:
Journal of cleaner production 2021 v.279 pp. 123266
ISSN:
0959-6526
Subject:
free radicals,   etc   ; equipment; gases; mechanical properties; rubber; wastes;     Show all 6 Subjects
Abstract:
... Based on the low-temperature mechano-chemical devulcanization (LTMD) method, we propose low-temperature rubber reclaiming equipment (LTRE) and a devulcanizing agent for rubber reclamation. Reclaiming experiments performed with the LTMD method and the traditional high-temperature atmospheric devulcanization (HTAD) method are conducted, and the performances of the reclaimed rubbers obtained by the t ...
DOI:
10.1016/j.jclepro.2020.123266

12. Free-radical promoted bromotrifluoromethylation of arylalkynes with CF3SO2Na and NaBrO3

Author:
Shang, Xiao-Jie; Luo, Rui; Zhu, Jing; Liu, Zhong-Quan
Source:
Tetrahedron letters 2021 v.62 pp. 152683
ISSN:
0040-4039
Subject:
free radicals,   etc   ; bromine; chemoselectivity; methodology; organic compounds; oxidants;     Show all 6 Subjects
Abstract:
... A novel method for bromotrifluoromethylation of arylalkyne was demonstrated. Utilizing NaSO₂CF₃ as the source of CF₃, various arylalkynes can be smoothly bromotrifluoromethylated via a NaBrO₃-mediated free radical process. In this reaction, NaBrO₃ acts as both single-electron oxidant and donor of the bromine atom. In addition, the present system features transition-metal free and high chemoselecti ...
DOI:
10.1016/j.tetlet.2020.152683

13. Synthesis of hydroxyethyl tetrathiatriarylmethyl radicals OX063 and OX071

Author:
Poncelet, Martin; Huffman, Justin L.; Khramtsov, Valery V.; Dhimitruka, Ilirian; Driesschaert, Benoit
Source:
RSC advances 2019 v.9 no.60 pp. 35073-35076
ISSN:
2046-2069
Subject:
free radicals
Abstract:
... We report the synthesis of hydroxyethyl tetrathiatriarylmethyl radical OX063 and its deuterated analogue OX071 for biomedical EPR applications. ...
DOI:
10.1039/c9ra08633a

14. A highly stretchable dielectric elastomer based on core–shell structured soft polymer-coated liquid-metal nanofillers

Author:
Su, Yaotian; Sui, Gang; Lan, Jinle; Yang, Xiaoping
Source:
Chemical communications 2020 v.56 no.78 pp. 11625-11628
ISSN:
1364-548X
Subject:
free radicals,   etc   ; liquids; nanocomposites; polymerization;     Show all 4 Subjects
Abstract:
... Elastomer, poly(n-butyl methacrylate), coated liquid metal (LM) nanodroplets (EGaIn@PBMA) were successfully fabricated via a facile in situ free radical polymerization method. The as-prepared soft nanoparticles can be directly hot-pressed into nanocomposites which not only exhibited ultra-high stretching flexibility (>400%) but also excellent dielectric properties with remarkably suppressed dielec ...
DOI:
10.1039/d0cc04224b

15. Delplot-Compliant Data: Molecular Observables versus Reaction Intermediates

Author:
Abo-Ghander, Nabeel S.; Klein, Michael T.
Source:
Energy & fuels 2020 v.34 no.12 pp. 15443-15447
ISSN:
1520-5029
Subject:
free radicals,   etc   ; energy; reaction mechanisms;     Show all 3 Subjects
Abstract:
... The Delplot analysis for reaction network elucidation involves the use of measured species and their yields as a function of reactant species. Highly reactive intermediates, such as free radical and other mechanistic intermediates, however, will often have large reaction rate constants relative to other species. This can cause the product classification by the Delplot technique, which uses only ob ...
DOI:
10.1021/acs.energyfuels.0c02465

16. Free Radical Research in Cancer

Author:
Čipak Gašparović, Ana
Source:
Antioxidants 2020 v.9 no.2
ISSN:
2076-3921
Subject:
free radicals,   etc   ; biodiversity; neoplasms; therapeutics;     Show all 4 Subjects
Abstract:
... It can be challenging to find efficient therapy for cancer due to its biological diversity [...] ...
DOI:
10.3390/antiox9020157

17. Isolable cyclic (alkyl)(amino)carbene–phosphonyl radical adducts

Author:
Livshits-Kritsman, Yulia; Tumanskii, Boris; Ménard, Gabriel; Dobrovetsky, Roman
Source:
Chemical communications 2020 v.56 no.9 pp. 1341-1344
ISSN:
1364-548X
Subject:
free radicals,   etc   ; carbenes; chemical reactions;     Show all 3 Subjects
Abstract:
... Phosphonyl radicals ([R₂PO]˙) and their adducts are proposed as intermediates in a number of important chemical and biological processes. Despite the great interest in these species, there are no examples of stable, isolated phosphonyl radicals or their adducts reported in the literature. Here we report the synthesis, EPR and theoretical study of stable, isolable cyclic (alkyl)(amino)carbene (cAA ...
DOI:
10.1039/c9cc09244g

18. Curing kinetic of self-promoted alicyclic-based bisphthalonitrile monomer

Author:
Lv, Jiangbo; Liu, Zhengzhou; Li, Renke; Liu, Yao; Hu, Jianghuai; Zeng, Ke; Yang, Gang
Source:
Thermochimica acta 2020 v.683 pp. 178446
ISSN:
0040-6031
Subject:
free radicals,   etc   ; catalytic activity; models;     Show all 3 Subjects
Abstract:
... Self-promoted alicyclic-based phthalonitrile possesses outstanding properties, which would be determined by the special free radical curing mechanism and curing process. Thus, the curing kinetic of alicyclic-based phthalonitrile was studied and the curing kinetic parameters were determined by DSC at various heating rates. Double fit peaks were used to analyze the reaction processes. The autocataly ...
DOI:
10.1016/j.tca.2019.178446

19. Are thymol, rosefuran, terpinolene and umbelliferone good scavengers of peroxyl radicals?

Author:
Boulebd, Houssem
Source:
Phytochemistry 2021 v.184 pp. 112670
ISSN:
0031-9422
Subject:
free radical scavengers; free radicals,   etc   ; antioxidant activity; aqueous solutions; ascorbic acid; caffeic acid; electron transfer; environment; essential oils; eugenol; guaiacol; hydrogen; pH; reaction mechanisms; terpinolene; thymol; umbelliferones; water;     Show all 18 Subjects
Abstract:
... DFT-based computational calculations have been used to investigate the hydroperoxyl radical scavenging activity of four essential oil constituents namely thymol (Thy), rosefuran (Ros), terpinolene (Ter), and umbelliferone (Umb). Different reaction mechanisms including formal hydrogen transfer (FHT), radical adduct formation (RAF), sequential proton loss electron transfer (SPLET), and sequential el ...
DOI:
10.1016/j.phytochem.2021.112670

20. Effect of different structural flaxseed lignans on the stability of flaxseed oil-in-water emulsion: An interfacial perspective

Author:
Cheng, Chen; Yu, Xiao; Huang, Fenghong; Peng, Dengfeng; Chen, Hongjian; Chen, Yashu; Huang, Qingde; Deng, Qianchun
Source:
Food chemistry 2021 v.357 pp. 129522
ISSN:
0308-8146
Subject:
free radicals,   etc   ; antioxidant activity; behavior; digestion; emulsions; food chemistry; lignans; linseed; linseed oil; storage;     Show all 10 Subjects
Abstract:
... The influences of the different structural flaxseed lignans on flaxseed oil (FO) emulsions during storage and digestion were investigated, focusing on their interfacial behavior. From perspective of interface, more than 60% of secoisolariciresinol (SECO) and the acidic hydrolysates of flaxseed lignan macromolecule (FLEH) were located on the interface of FO emulsions. It improved the stability of F ...
DOI:
10.1016/j.foodchem.2021.129522