Thiourea dioxide as a source of sulfonyl groups: photoredox generation of sulfones and sulfonamides from heteroaryl/aryl halides

2019 ◽  
Vol 55 (17) ◽  
pp. 2489-2492 ◽  
Author(s):  
Shengqing Ye ◽  
Yuewen Li ◽  
Jie Wu ◽  
Zhiming Li
Keyword(s):  
Dft Calculations ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Epr Spectroscopy ◽  
Aryl Halides ◽  
Light Irradiation ◽  
Efficient Synthesis ◽  
Radical Process ◽  
Thiourea Dioxide

Thiourea dioxide is applied as the source of sulfonyl groups for the efficient synthesis of heteroaryl sulfones and sulfonamides from heteroaryl halides under visible light irradiation. This transformation proceeds through a radical process via heteroaryl sulfinate intermediates, as supported by EPR spectroscopy and DFT calculations.

scholarly journals Redox-neutral photochemical Heck-type arylation of vinylphenols activated by visible light

2020 ◽  
Vol 11 (8) ◽  
pp. 2130-2135 ◽  
Author(s):  
Kangjiang Liang ◽  
Tao Li ◽  
Na Li ◽  
Yang Zhang ◽  
Lei Shen ◽  
...  
Keyword(s):  
Visible Light ◽  
Visible Light Irradiation ◽  
Aryl Halides ◽  
Light Irradiation

A regioselective and stereoselective Heck-type arylation of vinylphenols with non-activated (hetero)aryl halides was realized under visible light irradiation. The vinylphenolate anions acted as strong reducing photoactivators to activate (hetero)aryl halides.

scholarly journals Cobalt-catalyzed aminocarbonylation of (hetero)aryl halides promoted by visible light

2020 ◽  
Vol 11 (27) ◽  
pp. 7210-7213 ◽  
Author(s):  
Alexander M. Veatch ◽  
Erik J. Alexanian
Keyword(s):  
Visible Light ◽  
Visible Light Irradiation ◽  
Cobalt Catalyst ◽  
Aryl Halides ◽  
Light Irradiation

An aminocarbonylation of (hetero)aryl halides using a simple cobalt catalyst under visible light irradiation is presented.

Recent advances in the sulfonylation of C–H bonds with the insertion of sulfur dioxide

2018 ◽  
Vol 54 (89) ◽  
pp. 12561-12569 ◽  
Author(s):  
Guanyinsheng Qiu ◽  
Kaida Zhou ◽  
Jie Wu
Keyword(s):  
Sulfur Dioxide ◽  
Transition Metal ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Transition Metal Catalysis ◽  
Light Irradiation ◽  
Metal Catalysis ◽  
Radical Process ◽  
Recent Advances

Recent advances in the sulfonylation of C–H bonds with the insertion of sulfur dioxide are summarized. C–H bond sulfonylation under transition metal catalysis or through a radical process has been developed. In some cases, the sulfonylation can be performed under catalyst- and additive-free conditions, or can be facilitated by visible light irradiation. The efficiency is also studied by merging the radical process and metal catalysis.

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>.

Semiconductor Photocatalysts for Solar-to-Hydrogen Energy Conversion: Recent Advances of CdS

2020 ◽  
Vol 16 ◽  
Author(s):  
Yuxue Wei ◽  
Honglin Qin ◽  
Jinxin Deng ◽  
Xiaomeng Cheng ◽  
Mengdie Cai ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Visible Light ◽  
Hydrogen Evolution ◽  
Water Splitting ◽  
Visible Light Irradiation ◽  
Noble Metals ◽  
Light Irradiation ◽  
Photocatalytic Hydrogen Evolution ◽  
Theoretical Design ◽  
Recent Developments

Introduction: Solar-driven photocatalytic hydrogen production from water splitting is one of the most promising solutions to satisfy the increasing demands of a rapidly developing society. CdS has emerged as a representative semiconductor photocatalyst due to its suitable band gap and band position. However, the poor stability and rapid charge recombination of CdS restrict its application for hydrogen production. The strategy of using a cocatalyst is typically recognized as an effective approach for improving the activity, stability, and selectivity of photocatalysts. In this review, recent developments in CdS cocatalysts for hydrogen production from water splitting under visible-light irradiation are summarized. In particular, the factors affecting the photocatalytic performance and new cocatalyst design, as well as the general classification of cocatalysts, are discussed, which includes a single cocatalyst containing noble-metal cocatalysts, non-noble metals, metal-complex cocatalysts, metal-free cocatalysts, and multi-cocatalysts. Finally, future opportunities and challenges with respect to the optimization and theoretical design of cocatalysts toward the CdS photocatalytic hydrogen evolution are described. Background: Photocatalytic hydrogen evolution from water splitting using photocatalyst semiconductors is one of the most promising solutions to satisfy the increasing demands of a rapidly developing society. CdS has emerged as a representative semiconductor photocatalyst due to its suitable band gap and band position. However, the poor stability and rapid charge recombination of CdS restrict its application for hydrogen production. The strategy of using a cocatalyst is typically recognized as an effective approach for improving the activity, stability, and selectivity of photocatalysts. Methods: This review summarizes the recent developments in CdS cocatalysts for hydrogen production from water splitting under visible-light irradiation. Results: Recent developments in CdS cocatalysts for hydrogen production from water splitting under visible-light irradiation are summarized. The factors affecting the photocatalytic performance and new cocatalyst design, as well as the general classification of cocatalysts, are discussed, which includes a single cocatalyst containing noble-metal cocatalysts, non-noble metals, metal-complex cocatalysts, metal-free cocatalysts, and multi-cocatalysts. Finally, future opportunities and challenges with respect to the optimization and theoretical design of cocatalysts toward the CdS photocatalytic hydrogen evolution are described. Conclusion: The state-of-the-art CdS for producing hydrogen from photocatalytic water splitting under visible light is discussed. The future opportunities and challenges with respect to the optimization and theoretical design of cocatalysts toward the CdS photocatalytic hydrogen evolution are also described.

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