Copper-Promoted Oxidative C-H Bond Amination of Hydrazones:Synthesis of 1H-Indazoles and 1H-Pyrazoles
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چکیده
منابع مشابه
A Robust Protocol for Pd(II)-catalyzed C-3 Arylation of (1H) Indazoles and Pyrazoles: Total Synthesis of Nigellidine Hydrobromide.
C3-arylated indazole and pyrazoles are privileged structural motifs in agrochemicals and pharmaceuticals. C-3 C-H arylation of (1H) indazole and pyrazole has been a significant challenge due to the poor reactivity of the C-3 position. Herein, we report a practical Pd(II)/Phen catalyst and conditions for direct C-3 arylation of indazole and pyrazole with ArI or ArBr without using Ag additives as...
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A novel, efficient and practical method for copper-catalysed oxidative C-3 amination of quinoxalin-2(1H)-ones with primary or secondary amines as the nitrogen sources has been developed. A wide variety of 3-aminoquinoxalin-2(1H)-ones were prepared in up to 98% yield with good functional group tolerance for 24 examples. This synthetic strategy features atom economy, concise steps, easy operation...
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The use of a weakly coordinating monodentate directing group for copper mediated ortho-hydroxylation and amination reactions allows for the identification of an external oxazoline ligand as a promoter.
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An efficient route to substituted 1-aryl-1H-indazoles has been developed and optimized. The method involved the preparation of arylhydrazones from acetophenone or benzaldehyde substituted by fluorine at C2 and nitro at C5, followed by deprotonation and nucleophilic aromatic substitution (SNAr) ring closure in 45-90%. Modification of this procedure to a one-pot domino process was successful in t...
متن کاملSelective synthesis of 4-(sulfonyl)-methyl-1H-pyrazoles and (E)-4,5-dihydro-1H-pyrazoles from N-allenic sulfonylhydrazones.
Selective synthesis of 4-(sulfonyl)-methyl-1H-pyrazoles and (E)-4,5-dihydro-1H-pyrazoles from N-allenic sulfonylhydrazones with sulfonyl group migrations has been developed. A key feature of these reactions is that the migrations of the sulfonyl groups to different positions can be controlled by changing the Lewis acids.
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ژورنال
عنوان ژورنال: Acta Chimica Sinica
سال: 2015
ISSN: 0567-7351
DOI: 10.6023/a15040263