scholarly journals Decarboxylative thiolation of redox-active esters to free thiols and further diversification

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Tianpeng Cao ◽  
Tianxiao Xu ◽  
Ruting Xu ◽  
Xianli Shu ◽  
Saihu Liao
Keyword(s):  
Natural Products ◽  
Carboxylic Acid ◽  
Visible Light ◽  
High Efficiency ◽  
Direct Access ◽  
Active Esters ◽  
Redox Active ◽  
Sulfur Containing ◽  
Sulfur Containing Compounds

Abstract Thiols are important precursors for the synthesis of a variety of pharmaceutically important sulfur-containing compounds. In view of the versatile reactivity of free thiols, here we report the development of a visible light-mediated direct decarboxylative thiolation reaction of alkyl redox-active esters to free thiols based on the abundant carboxylic acid feedstock. This transformation is applicable to various carboxylic acids, including primary, secondary, and tertiary acids as well as natural products and drugs, forging a general and facile access to free thiols with diverse structures. Moreover, the direct access to free thiols affords an advantage of rapid in situ diversification with high efficiency to other important thiol derivatives such as sulfide, disulfide, thiocyanide, thioselenide, etc.

Accessing alkyl boronic esters via visible light-mediated decarboxylative addition reactions of redox-active esters

2020 ◽  
Vol 7 (15) ◽  
pp. 2003-2007
Author(s):  
Xianli Shu ◽  
Ruting Xu ◽  
Qiang Ma ◽  
Saihu Liao
Keyword(s):  
Carboxylic Acid ◽  
Visible Light ◽  
Addition Reaction ◽  
Addition Reactions ◽  
Active Esters ◽  
Redox Active ◽  
Boronic Esters

A visible light-mediated decarboxylative addition reaction for the synthesis of boronic esters based on abundant alkyl carboxylic acid feedstock has been developed.

Construction of Z-Scheme Bi3TaO7/Zn0.5Cd0.5S composites with high-efficiency for levofloxacin degradation under visible light irradiation

2021 ◽  
Author(s):  
Jingjing Xu ◽  
Yang liu ◽  
xueping li ◽  
Mindong Chen
Keyword(s):  
Visible Light ◽  
Hydrothermal Method ◽  
Visible Light Irradiation ◽  
High Efficiency ◽  
Light Irradiation ◽  
In Situ Growth ◽  
Composite Photocatalysts ◽  
Photocatalytic Activities

Direct Z-scheme Bi3TaO7/Zn0.5Cd0.5S composite photocatalysts were successfully prepared via an in-situ growth hydrothermal method. The photocatalytic activities of composites were investigated by the degradation of levofloxacin under visible light. And...

scholarly journals Sulfur and Sulfur Compounds in Plant Defence

2012 ◽  
Vol 7 (3) ◽  
pp. 1934578X1200700 ◽  
Author(s):  
Ifeanyi D. Nwachukwu ◽  
Alan J. Slusarenko ◽  
Martin C. H. Gruhlke
Keyword(s):  
Natural Products ◽  
New Technologies ◽  
Plant Defence ◽  
Sulfur Compounds ◽  
Oxidation States ◽  
Chemical Structures ◽  
Wide Range ◽  
Sulfur Containing ◽  
Sulfur Containing Compounds

The multiplicity of chemical structures of sulfur containing compounds, influenced in part by the element's several oxidation states, directly results in diverse modes of action for sulfur-containing natural products synthesized as secondary metabolites in plants. Sulfur-containing natural products constitute a formidable wall of defence against a wide range of pathogens and pests. Steady progress in the development of new technologies have advanced research in this area, helping to uncover the role of such important plant defence molecules like endogenously-released elemental sulphur, but also deepening current understanding of other better-studied compounds like the glucosinolates. As studies continue in this area, it is becoming increasingly evident that sulfur and sulfur compounds play far more important roles in plant defence than perhaps previously suspected.

Visible-Light-Induced Copper-Catalyzed Decarboxylative Coupling of Redox-Active Esters with N-Heteroarenes

2019 ◽  
Vol 21 (14) ◽  
pp. 5728-5732 ◽  
Author(s):  
Xue-Li Lyu ◽  
Shi-Sheng Huang ◽  
Hong-Jian Song ◽  
Yu-Xiu Liu ◽  
Qing-Min Wang
Keyword(s):  
Visible Light ◽  
Active Esters ◽  
Redox Active ◽  
Decarboxylative Coupling

Nucleophilic (Radio)Fluorination of Redox-Active Esters via Radical-Polar Crossover Enabled by Photoredox Catalysis

2020 ◽  
Author(s):  
Eric Webb ◽  
John Park ◽  
Erin L. Cole ◽  
David J. Donnelly ◽  
Samuel Bonacorsi, Jr. ◽  
...  
Keyword(s):  
Visible Light ◽  
Visible Light Irradiation ◽  
Light Irradiation ◽  
Active Esters ◽  
Mild Conditions ◽  
Redox Active ◽  
Active Ester ◽  
Electron Transfers ◽  
Ester Substrate ◽  
Nucleophilic Fluorination

<p>We report a redox-neutral method for nucleophilic fluorination of N-hydroxyphthalimide esters using an Ir photocatalyst under visible light irradiation. The method provides access to a broad range of aliphatic fluorides, including primary, secondary, and tertiary benzylic fluorides as well as unactivated tertiary fluorides, that are typically inaccessible by nucleophilic fluorination due to competing elimination. In addition, we show that the decarboxylative fluorination conditions are readily adapted to radiofluorination with [<sup>18</sup>F]KF. We propose that the reactions proceed by two electron transfers between the Ir catalyst and redox-active ester substrate to afford a carbocation intermediate that undergoes subsequent trapping by fluoride. Examples of trapping with O- and C-centered nucleophiles and deoxyfluorination via N-hydroxyphthalimidoyl oxalates are also presented, suggesting that this approach may offer a general blueprint for affecting redox-neutral SN1 substitutions under mild conditions.</p>

Visible-light-induced iodine anion catalyzed decarboxylative/ deaminative C-H alkylation of enamides

2021 ◽  
Author(s):  
Jia-Xin Wang ◽  
Ya-Ting Wang ◽  
Hao Zhang ◽  
Ming-Chen Fu
Keyword(s):  
Amino Acid ◽  
Visible Light ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Active Esters ◽  
Cross Coupling Reactions ◽  
Redox Active ◽  
Iodine Anion

A visible-light-induced iodine anion catalyzed C-H stereoselective alkylation of enamides has been developed. Redox-active esters and Katritzky salts of the amino acid are amenable for decarboxylative/deaminative cross-coupling reactions, delivering various...

Fabrication of high-efficiency CdS@TiO2@C/Ti3C2 composites photocatalyst for the degradation of TC-HCl under visible light

2022 ◽  
Author(s):  
Juanjuan Ren ◽  
Lili Wang ◽  
Qianqian Gong ◽  
Jingyue Xuan ◽  
Meiling Sun ◽  
...  
Keyword(s):  
Transition Metal ◽  
Visible Light ◽  
High Efficiency ◽  
Tetracycline Hydrochloride ◽  
Two Dimensional ◽  
Layered Transition Metal

A novel CdS@TiO2@C/Ti3C2 composite as high-efficiency photocatalyst for the degradation of tetracycline hydrochloride (TC-HCl) was fabricated by in situ oxidizing two-dimensional (2D) layered transition metal Ti3C2 MXene and subsequently compounding...

scholarly journals Electrochemical Nozaki–Hiyama–Kishi Coupling: Scope, Applications, and Mechanism

2021 ◽  
Author(s):  
Yang Gao ◽  
david hill ◽  
wei hao ◽  
Brendon J. McNicholas ◽  
julien Vantourout ◽  
...  
Keyword(s):  
Cyclic Voltammetry ◽  
Bond Formation ◽  
Active Esters ◽  
Vinyl Halides ◽  
Redox Active ◽  
Chemical Techniques ◽  
Detailed Kinetics ◽  
Limited Scope

One of the most oft-employed methods for C–C bond formation involving the coupling of vinyl-halides with aldehydes catalyzed by Ni and Cr (Nozaki–Hiyama–Kishi, NHK) has been rendered more practical using an electroreductive manifold. Although early studies pointed to the feasibility of such a process those precedents were never applied by others due to cumbersome setups and limited scope. Here we show that a carefully optimized electroreductive procedure can enable a more sustainable approach to NHK, even in an asymmetric fashion on highly complex medicinally relevant systems. The e-NHK can even enable non-canonical substrate classes, such as redox-active esters, to participate with low loadings of Cr when conventional chemical techniques fail. A combination of detailed kinetics, cyclic voltammetry, and in situ UV-vis spectroelectrochemistry of these processes illuminates the subtle features of this mechanistically intricate process.

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