scholarly journals Transition-metal-free Oxidative Coupling Reactions for the Formation of C–C and C–N Bonds Mediated by TEMPO and its Derivatives

2012 ◽  
Vol 66 (6) ◽  
pp. 413-417 ◽  
Author(s):  
Sandip Murarka ◽  
Sebastian Wertz ◽  
Armido Studer
Keyword(s):  
Transition Metal ◽  
Oxidative Coupling ◽  
Coupling Reactions ◽  
Metal Free ◽  
Oxidative Coupling Reactions

scholarly journals An Efficient Metal-Free Oxidative Esterification and Amination of Benzyl C–H Bond

Molecules ◽  
2020 ◽  
Vol 25 (7) ◽  
pp. 1527
Author(s):  
Saiwen Liu ◽  
Ru Chen ◽  
Guowen He ◽  
Jin Zhang
Keyword(s):  
Carboxylic Acids ◽  
Oxidative Coupling ◽  
Coupling Reactions ◽  
Coupling Reagents ◽  
Oxidative Esterification ◽  
Metal Free ◽  
High Yields ◽  
Oxidative Coupling Reactions

An esterification and amination of benzylic C–H bonds was developed by using 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) under metal- and iodide-free conditions. Both carboxylic acids and amines could be used as ideal coupling partners for the oxidative coupling reactions with various diarylmethanes. A close to equal amount of coupling reagents was enough to afford the product in good to high yields.

An Unprecedented Cyano-Induced Sodium Nitrite-Catalyzed C(sp3)-H and C(sp2)-H Coupling Reaction

2018 ◽  
Vol 15 (7) ◽  
pp. 989-994 ◽  
Author(s):  
Ling Li ◽  
Bo Su ◽  
Yuxiu Liu ◽  
Qingmin Wang
Keyword(s):  
Sodium Nitrite ◽  
Oxidative Coupling ◽  
High Resolution Mass Spectrometry ◽  
Coupling Reaction ◽  
13C Nmr Spectroscopy ◽  
Coupling Reactions ◽  
Reaction Conditions ◽  
1H And 13C Nmr ◽  
Oxidative Coupling Reaction ◽  
Oxidative Coupling Reactions

Aim and Objective: During the investigation of sodium nitrite-catalyzed oxidative coupling reaction of aryls, an unprecedented C(sp2)-H and C(sp3)-H coupling of substituted 2-aryl acetonitrile was found. Materials and Methods: The structure of the coupled product was confirmed by 1H and 13C NMR spectroscopy and high-resolution mass spectrometry (HRMS), and comparison of its derivatives with known compounds. The effects of methoxy group in the benzene ring on the reaction were evaluated. Results: The optimized reaction conditions are summarized as follows: CF3SO3H/substrate = 1.5 equiv., NaNO2/substrate = 0.3 equiv., CH3CN as solvent. 2-(4-Methoxyphenyl)acetonitrile and 2-(3,4,5- trimethoxyphenyl)acetonitrile could also generate C(sp2)-H and C(sp3)-H coupling. The coupling reaction occurred as a typical radial mechanism. Conclusion: An unprecedented cyano-induced, NaNO2-catalyzed oxidative C(sp3)-H and C(sp2)-H coupling was reported. The reaction proceeded under very mild conditions, using O2 in the air as terminal oxidant. The unique oxidative manner might provide more inspiration for the development of intriguing oxidative coupling reactions.

Diiiodine/Potassium Persulfate Mediated Synthesis of 1,2,3-Thiadiazoles from N-Tosylhydrazones and a Thiocyanate Salt as a Sulfur Source under Transition-Metal-Free Conditions

Synlett ◽  
2021 ◽  
Author(s):  
Yadong Sun ◽  
Ablimit Abdukader ◽  
Yuhan Lu ◽  
Chenjiang Liu
Keyword(s):  
Transition Metal ◽  
Efficient Method ◽  
Room Temperature ◽  
Functional Group ◽  
Ammonium Thiocyanate ◽  
Potassium Persulfate ◽  
Sulfur Source ◽  
Coupling Reactions ◽  
Wide Scope ◽  
Metal Free

AbstractA highly efficient method for the synthesis of 1,2,3-thiadiazoles has been developed by utilizing readily available tosylhydrazones and ammonium thiocyanate with ecofriendly EtOH as the solvent at room temperature. The reaction shows a wide scope of substrates and good functional-group tolerance. This protocol can be scaled up to a gram level and can be applied to coupling reactions with 4-(4-bromophenyl)-1,2,3-thiadiazole as the substrate.

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