Photoredox Catalysis in C-S Bond Construction: Recent Progress in Photo-Catalyzed Formation of Sulfones and Sulfoxides

2017 ◽  
Vol 360 (3) ◽  
pp. 386-400 ◽  
Author(s):  
Jie Zhu ◽  
Wen-Chao Yang ◽  
Xiao-dong Wang ◽  
Lei Wu
Keyword(s):  
Recent Progress ◽  
Photoredox Catalysis

scholarly journals An overview on disulfide-catalyzed and -cocatalyzed photoreactions

2020 ◽  
Vol 16 ◽  
pp. 1418-1435 ◽  
Author(s):  
Yeersen Patehebieke
Keyword(s):  
Electron Transfer ◽  
Hydrogen Atom ◽  
Recent Progress ◽  
Hydrogen Atom Transfer ◽  
Present Review ◽  
Photoredox Catalysis ◽  
Multiple Bonds ◽  
Thiyl Radicals ◽  
Mild Conditions ◽  
Photocatalytic Reactions

Disulfides are versatile catalysts. They can be photocatalysts, hydrogen atom transfer (HAT) catalysts, cocatalysts, or initiators in photocatalytic reactions. Under photoirradiation, organic disulfides can be easily cleaved into free thiyl radicals (RS•) and can reversibly add to unsaturated multiple bonds to catalyze a variety of functionalization reactions under mild conditions. In photoredox catalysis reactions, an excellent electron transfer ability and excellent radical properties also made these thiyl radicals powerful HAT catalysts. They have increasingly been proven useful in various types of organic photoreactions, such as cyclizations, anti-Markovnikov additions, aromatic olefin carbonylations, isomerizations, etc. They are a class of green, economic, mild, and chemoselective radical catalysts that deserve more attention. The present review highlights the recent progress in the field of disulfide-catalyzed and -cocatalyzed photocatalytic reactions for different reaction types.

Pyrylium Salts: Selective Reagents for the Activation of Primary Amino Groups in Organic Synthesis

Synthesis ◽  
2019 ◽  
Vol 52 (04) ◽  
pp. 489-503 ◽  
Author(s):  
Yue Pang ◽  
Daniel Moser ◽  
Josep Cornella
Keyword(s):  
Recent Progress ◽  
Rapid Development ◽  
Historical Context ◽  
Building Blocks ◽  
Short Review ◽  
Pyridinium Salts ◽  
Photoredox Catalysis ◽  
Amino Groups ◽  
Pyrylium Salts ◽  
Primary Amino

Primary amino groups represent an ubiquitous category of functionalities in synthetic building blocks, drugs, and natural products. Therefore, such functionalities offer themselves as perfect handles for late-stage functionalization, and the development of robust and efficient strategies to transform these groups is highly desirable. Despite the extremely challenging activation of the C–N bond, the past few years have witnessed the rapid development of deaminative transformations using pyrylium salts as activating reagents. In most cases, the pyridinium salts formed were activated by single electron transfer, giving alkyl radicals which were used in a series of transformations via nickel and photoredox catalysis. This short review aims to give an overview to related properties of pyrylium salts, their historical significance, and summarize the recent progress in the field of deaminative transformations using these reagents.1 Introduction2 Pyrylium and Pyridinium Salts2.1 Historical Context2.2 Structure and Reactivity2.3 Pyrylium Synthesis2.4 Historical Context of the Reactivity of Pyridinium Salts3 Recent Progress on Deaminative Transformations of Primary Amino Groups by Pyrylium Salts3.1 Metal-Catalyzed Cross-Couplings3.2 Photoredox Catalysis and Photoinduced Reactions for C–C Bond Constructions3.3 Borylations3.4 SNAr Functionalization of Aminoheterocycles4 Conclusion

scholarly journals Visible-light-mediated copper photocatalysis for organic syntheses

2021 ◽  
Vol 17 ◽  
pp. 2520-2542
Author(s):  
Yajing Zhang ◽  
Qian Wang ◽  
Zongsheng Yan ◽  
Donglai Ma ◽  
Yuguang Zheng
Keyword(s):  
Renewable Energy ◽  
Transition Metals ◽  
Green Chemistry ◽  
Visible Light ◽  
Copper Complexes ◽  
Recent Progress ◽  
Photoredox Catalysis ◽  
Organic Halide ◽  
The Past ◽  
Further Development

Photoredox catalysis has been applied to renewable energy and green chemistry for many years. Ruthenium and iridium, which can be used as photoredox catalysts, are expensive and scarce in nature. Thus, the further development of catalysts based on these transition metals is discouraged. Alternative photocatalysts based on copper complexes are widely investigated, because they are abundant and less expensive. This review discusses the scope and application of photoinduced copper-based catalysis along with recent progress in this field. The special features and mechanisms of copper photocatalysis and highlights of the applications of the copper complexes to photocatalysis are reported. Copper-photocatalyzed reactions, including alkene and alkyne functionalization, organic halide functionalization, and alkyl C–H functionalization that have been reported over the past 5 years, are included.

Electron-Mirror Microscopic Aspects of Ferroelectric Domains of BaTiO3 And Ca2Sr (C2H5CO2)6

1970 ◽  
Vol 28 ◽  
pp. 478-479
Author(s):  
Teruo Someya ◽  
Jinzo Kobayashi
Keyword(s):  
Surface Layer ◽  
Electric Fields ◽  
Quantitative Study ◽  
Recent Progress ◽  
Ferroelectric Domain ◽  
Resolving Power ◽  
Surface Pattern ◽  
Crystal Surfaces ◽  
One Dimensional ◽  
Ferroelectric Domains

Recent progress in the electron-mirror microscopy (EMM), e.g., an improvement of its resolving power together with an increase of the magnification makes it useful for investigating the ferroelectric domain physics. English has recently observed the domain texture in the surface layer of BaTiO3. The present authors ) have developed a theory by which one can evaluate small one-dimensional electric fields and/or topographic step heights in the crystal surfaces from their EMM pictures. This theory was applied to a quantitative study of the surface pattern of BaTiO3).

The Nature of Oxide Surfaces: Topographic and Electronic Structure

1993 ◽  
Vol 51 ◽  
pp. 966-967
Author(s):  
Dawn A. Bonnell ◽  
Yong Liang
Keyword(s):  
Transition Metal Oxides ◽  
Electronic Structures ◽  
Recent Progress ◽  
Spatial Localization ◽  
Level Of Detail ◽  
Scanning Tunneling ◽  
Oxide Surfaces ◽  
Tunneling Microscopy ◽  
Considerable Effort ◽  
Complete Understanding

Recent progress in the application of scanning tunneling microscopy (STM) and tunneling spectroscopy (STS) to oxide surfaces has allowed issues of image formation mechanism and spatial resolution limitations to be addressed. As the STM analyses of oxide surfaces continues, it is becoming clear that the geometric and electronic structures of these surfaces are intrinsically complex. Since STM requires conductivity, the oxides in question are transition metal oxides that accommodate aliovalent dopants or nonstoichiometry to produce mobile carriers. To date, considerable effort has been directed toward probing the structures and reactivities of ZnO polar and nonpolar surfaces, TiO2 (110) and (001) surfaces and the SrTiO3 (001) surface, with a view towards integrating these results with the vast amount of previous surface analysis (LEED and photoemission) to build a more complete understanding of these surfaces. However, the spatial localization of the STM/STS provides a level of detail that leads to conclusions somewhat different from those made earlier.

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