[4 + 1] Cycloaddition Reaction of α,β-Alkynic Hydrazones and KSCN under Transition-Metal-Free Conditions: Synthesis of N-Iminoisothiazolium Ylides

2018 ◽  
Vol 83 (18) ◽  
pp. 11118-11124 ◽  
Author(s):  
Bei-Bei Liu ◽  
Wen-Bin Cao ◽  
Fei Wang ◽  
Shun-Yi Wang ◽  
Shun-Jun Ji
Keyword(s):  
Transition Metal ◽  
Cycloaddition Reaction ◽  
Metal Free

scholarly journals SET activation of nitroarenes by 2-azaallyl anions as a straightforward access to 2,5-dihydro-1,2,4-oxadiazoles

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Dong Zou ◽  
Lishe Gan ◽  
Fan Yang ◽  
Huan Wang ◽  
Youge Pu ◽  
...  
Keyword(s):  
Transition Metal ◽  
Experimental Evidence ◽  
Radical Anion ◽  
Reaction Pathway ◽  
Cycloaddition Reaction ◽  
Electron Donors ◽  
Ring Closure ◽  
Computational Studies ◽  
Metal Free ◽  
Radical Coupling

AbstractThe use of nitroarenes as amino sources in synthesis is challenging. Herein is reported an unusual, straightforward, and transition metal-free method for the net [3 + 2]-cycloaddition reaction of 2-azaallyl anions with nitroarenes. The products of this reaction are diverse 2,5-dihydro-1,2,4-oxadiazoles (>40 examples, up to 95% yield). This method does not require an external reductant to reduce nitroarenes, nor does it employ nitrosoarenes, which are often used in N–O cycloadditions. Instead, it is proposed that the 2-azaallyl anions, which behave as super electron donors (SEDs), deliver an electron to the nitroarene to generate a nitroarene radical anion. A downstream 2-azaallyl radical coupling with a newly formed nitrosoarene is followed by ring closure to afford the observed products. This proposed reaction pathway is supported by computational studies and experimental evidence. Overall, this method uses readily available materials, is green, and exhibits a broad scope.

Transition-metal-free catalytic hydroboration reduction of amides to amines

2020 ◽  
Vol 7 (21) ◽  
pp. 3515-3520
Author(s):  
Wubing Yao ◽  
Jiali Wang ◽  
Aiguo Zhong ◽  
Shiliang Wang ◽  
Yinlin Shao
Keyword(s):  
Transition Metal ◽  
Selective Catalytic Reduction ◽  
Catalytic Reduction ◽  
Value Added ◽  
Metal Free

The selective catalytic reduction of amides to value-added amine products is a desirable but challenging transformation.

Deaminative carbonylative thioesterification of activated alkylamines with thiophenols under transition-metal-free conditions

2021 ◽  
Author(s):  
Fengqian Zhao ◽  
Xiao-Feng Wu
Keyword(s):  
Free Radical ◽  
Transition Metal ◽  
Metal Free

A transition-metal-free radical carbonylation of activated alkylamines with thiophenols has been successfully developed. Various thioesters were selectively produced with moderate to good yields.

Regioselective C3-H Trifluoromethylation of 2H-Indazole Under Transition-Metal-Free Photoredox Catalysis

2019 ◽  
Author(s):  
Arumugavel Murugan ◽  
Venkata Nagarjuna Babu ◽  
Nagaraj Sabarinathan ◽  
Sharada Duddu. S
Keyword(s):  
Transition Metal ◽  
Visible Light ◽  
Practical Approach ◽  
Hypervalent Iodine ◽  
Radical Mechanism ◽  
Photoredox Catalysis ◽  
Metal Free

Here we report a visible-light-promoted metal-free regioselective C3-H trifluoromehtylation reaction that proceeds via radical mechanism and which supported by control experiments. The combination of photoredox catalysis and hypervalent iodine reagent provides a practical approach for the present trifluoromethylation reaction and synthesis of a library of trifluoromethylated indazoles.

Selective Oxidation of Alcohols Catalyzed by a Transition Metal-Free System of NHPI/DDQ/NaNO2

2011 ◽  
Vol 32 (1) ◽  
pp. 118-122 ◽  
Author(s):  
Lipeng ZHOU ◽  
Chaofeng ZHANG ◽  
Tao FANG ◽  
Bingbing ZHANG ◽  
Ying WANG ◽  
...  
Keyword(s):  
Transition Metal ◽  
Selective Oxidation ◽  
Free System ◽  
Metal Free ◽  
Oxidation Of Alcohols

Defect engineering and characterization of active sites for efficient electrocatalysis

Nanoscale ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 3327-3345
Author(s):  
Xuecheng Yan ◽  
Linzhou Zhuang ◽  
Zhonghua Zhu ◽  
Xiangdong Yao
Keyword(s):  
Transition Metal ◽  
Active Sites ◽  
Defect Engineering ◽  
Metal Free

This review highlights recent advancements in defect engineering and characterization of both metal-free carbons and transition metal-based electrocatalysts.

Transition metal free, green and facile halogenation of ketene dithioacetals using a KX–oxidant system

2021 ◽  
Author(s):  
Vishakha Rai ◽  
Ganesh Shivayogappa Sorabad ◽  
Mahagundappa Rachappa Maddani
Keyword(s):  
Transition Metal ◽  
Ambient Temperature ◽  
Metal Free ◽  
Ketene Dithioacetals ◽  
System P ◽  
Oxidative Halogenation ◽  
Potassium Halide

A facile oxidative halogenation of α-oxo ketene dithioacetals is achieved by using a potassium halide and an oxidant combination under transition metal free conditions at ambient temperature.

Highly chemoselective deoxygenation of N-heterocyclic N-oxides under transition metal-free conditions

2021 ◽  
Vol 19 (16) ◽  
pp. 3735-3742
Author(s):  
Se Hyun Kim ◽  
Ju Hyeon An ◽  
Jun Hee Lee
Keyword(s):  
Transition Metal ◽  
Visible Light ◽  
Eosin Y ◽  
Metal Free ◽  
Simple Protocol

Here, we provide an operationally simple protocol for the highly chemoselective deoxygenation of various functionalized N-heterocyclic N-oxides under visible light-mediated photoredox conditions with Na2-eosin Y as an organophotocatalyst.

scholarly journals Transition-Metal-Free Cross-Coupling of Aryl Halides with Arylstannanes

2021 ◽  
Author(s):  
Qing He ◽  
Wenli Wang ◽  
Yong Liang ◽  
Zunting Zhang ◽  
Stanislaw F. Wnuk
Keyword(s):  
Transition Metal ◽  
Cross Coupling ◽  
Aryl Halides ◽  
Metal Free
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