Visible-light organic photoredox catalytic cascade reaction

2021 ◽  
Author(s):  
Guo-Qiang Xu ◽  
Peng-Fei Xu
Keyword(s):  
Transition Metals ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Cascade Reactions ◽  
Cascade Reaction ◽  
Light Irradiation ◽  
The Past

Over the past years, impressive progress has been made on the development of organic photoredox catalytic cascade reactions without the participation of expensive and toxic transition-metals under visible light irradiation....

Dehydrogenative 6π Heterocyclization under Visible Light Irradiation and Mechanistic Insights

2021 ◽  
Author(s):  
Zhao Zhang ◽  
Haohua Chen ◽  
Niklas Keller ◽  
Qin Xiong ◽  
Lei Liu ◽  
...  
Keyword(s):  
Transition Metals ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Light Irradiation ◽  
Reaction Proceeds ◽  
Visible Light Driven

A visible-light-driven oxidative 6π heterocycilization for the synthesis of structurally diverse π-conjugated polycyclic 1-aminoisoquinolines has been developed. The reaction proceeds under visible-light or sunshine, obviates photocatalyst and transition-metals, and features...

Photocatalyst- and transition-metal-free α-allylation of N-aryl tetrahydroisoquinolines mediated by visible light

2020 ◽  
Vol 22 (3) ◽  
pp. 646-650 ◽  
Author(s):  
Zhuohua Li ◽  
Pengju Ma ◽  
Yongzhu Tan ◽  
Yufei Liu ◽  
Min Gao ◽  
...  
Keyword(s):  
Transition Metal ◽  
Transition Metals ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Light Irradiation ◽  
Metal Free

A convenient and efficient α-allylation of N-aryl tetrahydroisoquinolines has been achieved. This transformation can be realized under only visible light irradiation without the aid of transition metals or photocatalysts.

Synthesis of trifluoroalkyl or difluoroalkyl phenanthridine derivatives via cascade reaction using an intramolecular cyano group as a radical acceptor under photoredox catalysis

2018 ◽  
Vol 16 (3) ◽  
pp. 414-423 ◽  
Author(s):  
Xu Liu ◽  
Zhongjie Wu ◽  
Zeguo Zhang ◽  
Ping Liu ◽  
Peipei Sun
Keyword(s):  
Visible Light ◽  
Visible Light Irradiation ◽  
Cyano Group ◽  
Cascade Reaction ◽  
Light Irradiation ◽  
Photoredox Catalysis ◽  
Cascade Cyclization ◽  
Radical Acceptor ◽  
Cyclization Process

In the presence of Ru(phen)3Cl2 or fac-Ir(ppy)3 under visible-light irradiation, the addition of fluorinated radicals to N-arylacrylamides followed by an intramolecular cyano group insertion cascade cyclization process produced the target compounds in moderate to good yields.

Visible-light mediated cascade cyclization of ene-vinylidenecyclopropanes: access to fluorinated heterocyclic compounds

2021 ◽  
Author(s):  
Min Shi ◽  
Zhe Meng ◽  
Xiaoyu Zhang
Keyword(s):  
Visible Light ◽  
Visible Light Irradiation ◽  
Heterocyclic Compounds ◽  
Cascade Reaction ◽  
Light Irradiation ◽  
Cascade Cyclization ◽  
Perfluoroalkyl Iodide

A fluoroalkylation and cycloisomerization cascade reaction of ene-VDCP with ethyl iododifluoroacetate or perfluoroalkyl iodide upon visible-light irradiation was disclosed in this paper, affording the desired fluorinated cyclization products in moderate...

Visible-light-induced photoxidation-Povarov cascade reaction: synthesis of 2-arylquinoline through alcohol and N-benzylanilines under mild conditions via Ag/g-C3N4 nanometric semiconductor catalyst

2020 ◽  
Vol 56 (35) ◽  
pp. 4840-4843 ◽  
Author(s):  
Peng Wang ◽  
Xiaowen Wang ◽  
Xiyu Niu ◽  
Li Zhu ◽  
Xiaoquan Yao
Keyword(s):  
Visible Light ◽  
Visible Light Irradiation ◽  
Cascade Reaction ◽  
Light Irradiation ◽  
Reaction Synthesis ◽  
Mild Conditions

Ag/g-C3N4 nanometric semiconductor catalyzed cascade reaction for the synthesis of 2-arylquinoline through alcohol and N-benzylanilines under visible light irradiation.

scholarly journals Electrochemical Investigation of Doped Titanium Dioxide

2008 ◽  
Vol 2008 ◽  
pp. 1-8 ◽  
Author(s):  
J. W. J. Hamilton ◽  
J. A. Byrne ◽  
C. McCullagh ◽  
P. S. M. Dunlop
Keyword(s):  
Transition Metals ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Sol Gel ◽  
Response Spectra ◽  
Light Irradiation ◽  
Photocurrent Response ◽  
Defect Level ◽  
Current Time ◽  
Potential Dependence

Thin films of transition-metal doped (0.2, 1.0, and 5.0 atom%)TiO2were prepared on titanium foil using a sol-gel route catalyzed by ammonium acetate. Dopants investigated were the fourth-period transition metals. The prepared films were characterised by Raman spectroscopy, Auger electron spectroscopy, and photoelectrochemical methods. The films doped with transition metals showed a lower photocurrent response than undoped samples. No major red shift in the photocurrent response spectra of the doped films was observed. A photocurrent response was observed under visible light irradiation of the samples and was potential dependent peaking around−0.3 V (SCE), which is indicative of electron promotion from a filled defect level. Examination of the defect level potential dependence by analysis of the current-time response under chopped illumination at fixed potential (−0.8 V–+1.07 V) gave a good correlation with the potential dependence observed in the visible light irradiation studies.

scholarly journals Photochemical [2+1]-Cycloadditions of Nucleophilic Carbenes

2021 ◽  
Author(s):  
Amanda Bunyamin ◽  
Anastasios Polyzos ◽  
Daniel Priebbenow
Keyword(s):  
Chemical Synthesis ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Cascade Reaction ◽  
Light Irradiation ◽  
Nucleophilic Carbenes

Visible light induced singlet nucleophilic carbene intermediates undergo rapid [2+1]-cycloaddition with tethered olefins to afford unique bicyclo[3.1.0]hexane and bicyclo[4.1.0]heptane scaffolds. This cyclopropanation proceeds using only visible light irradiation, circumventing the use of exogenous (photo)catalysts or sensitisers and showcases an underexplored mode of reactivity for nucleophilic carbenes in chemical synthesis. The discovery of additional transformations including a cyclopropanation/retro-Michael/Michael cascade reaction to afford chromanone derivatives are also described.

Cu Doped TiO2: Visible Light Assisted Photocatalytic Antimicrobial Activity and High Temperature Anatase Stability

2018 ◽  
Author(s):  
Snehamol Mathew ◽  
Priyanka Ganguly ◽  
Stephen Rhatigan ◽  
Vignesh Kumaravel ◽  
Ciara Byrne ◽  
...  
Keyword(s):  
Visible Light ◽  
Visible Light Irradiation ◽  
Density Functional ◽  
Anatase Phase ◽  
Sol Gel ◽  
Chemical Properties ◽  
Light Irradiation ◽  
Health Concern ◽  
Bacterial Inactivation ◽  
X Ray

Indoor surface contamination by microbes is a major public health concern. A damp environment is one potential sources for microbe proliferation. Smart photocatalytic coatings on building surfaces using semiconductors like titania (TiO<sub>2</sub>) can effectively curb this growing threat.<b> </b>Metal-doped titania in anatase phase has been proved as a promising candidate for energy and environmental applications. In this present work, the antimicrobial efficacy of copper (Cu) doped TiO<sub>2 </sub>(Cu-TiO<sub>2</sub>) was evaluated against <i>Escherichia coli</i> (Gram-negative) and <i>Staphylococcus aureus</i> (Gram-positive) under visible light irradiation. Doping of a minute fraction of Cu (0.5 mol %) in TiO<sub>2 </sub>was carried out <i>via</i> sol-gel technique. Cu-TiO<sub>2</sub> further calcined at various temperatures (in the range of 500 °C – 700 °C) to evaluate the thermal stability of TiO<sub>2</sub> anatase phase. The physico-chemical properties of the samples were characterised through X-ray diffraction (XRD), Raman spectroscopy, X-ray photo-electron spectroscopy (XPS) and UV-visible spectroscopy techniques. XRD results revealed that the anatase phase of TiO<sub>2</sub> was maintained well, up to 650 °C, by the Cu dopant. UV-DRS results suggested that the visible light absorption property of Cu-TiO<sub>2 </sub>was enhanced and the band gap is reduced to 2.8 eV. Density functional theory (DFT) studies emphasises the introduction of Cu<sup>+</sup> and Cu<sup>2+</sup> ions by replacing Ti<sup>4+</sup> ions in the TiO<sub>2</sub> lattice, creating oxygen vacancies. These further promoted the photocatalytic efficiency. A significantly high bacterial inactivation (99.9%) was attained in 30 mins of visible light irradiation by Cu-TiO<sub>2</sub>.

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