- Copper-Catalyzed Cyclization of Aryl Amines and Aryldiazonium Salts under Air: Access to N-2-Aryl-Naphthotriazoles
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A catalytic and step economic protocol for the construction of N-2-aryl-naphthotriazoles via copper-catalyzed cyclization of aryl amines and aryldiazonium salts is reported. With dioxygen in the air as termial oxidants under copper catalysis, various N-2-aryl-naphthotriazoles were synthesized in high yields. Importantly, this protocol features the sufficient inhibition of the classic C-N2 bond cleavage process of aryldiazonium tetrafluoroborates under copper catalysis and the undesired dehydrogenative coupling of aryl amines under oxidative conditions. Preliminary mechanistic studies indicated that a radical procedure might not be involved in this transformation. In addition, simple decoration of the obtained compounds delivers novel and attractive tetraphenylethylene moiety containing N-2-aryl-naphthotriazole derivatives. (Figure presented.).
- Zhu, Chuanle,Zeng, Hao,Chen, Fulin,Liu, Chi,Jiang, Huanfeng
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supporting information
p. 5149 - 5159
(2019/11/03)
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- Oxidative Cyclizations. VIII. Mechanisms of Oxidation of ortho-Substituted Benzenamines and Improved Cyclizations by Bis(acetato-O)phenyliodine
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Published reports describe the oxidative cyclization of suitable ortho-substituted arenamines to form such products as 2,1-benzisoxazoles, benzofurazan 1-oxides and benzotriazoles, by using bis(acetato-O)phenyliodine at room temperature.However, the reactions are often inconveniently slow.We now report attempts to achieve short reaction times with more powerful iodine(III) oxidants.These often failed to give cyclic products, but the results enable us to argue that the reaction competing with cyclization involves the arenaminyl cation ArN+H.When such cations are predicted to be relatively unstable, the parent arenamine can be rapidly cyclized in high yield by oxidation with bis(acetato-O)phenyliodine in boiling benzene.
- Dyall, Leonard K.,Harvey, Jacqueline J.,Jarman, Tony B.
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p. 371 - 384
(2007/10/02)
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- A Simple Route to 2H-Naphtho1,2,3-triazoles
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1-Arylazo-2-chloro-naphthalenes 9a-9k and 2,4-diarylazo-1-chloronaphthalenes 10a-10c are transformed by the reaction with sodium azide into 2-arylsubstituted 2H-Naphtho1,2,3-triazoles 13a-13k and 14a-14c, resp., which exhibit fluorescence if they a
- Hartmann, H.,Schulze, M.,Guenther, R.
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p. 331 - 335
(2007/10/02)
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- SYNTHESIS OF MONOXIMES OF 2-ARYL-2H-NAPHTHOTRIAZOLE-4,5-QUINONES AND THEIR REARRANGEMENT TO TRIAZOLYLCARBOXYLIC ACID
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Oximation of 2-aryl-2H-naphthotriazole-4,5-quinones gave the 4-oximes.The rearrangement of the latter in alkaline medium in the presence of benzenesulfonyl chloride to triazolylcarboxylic acids was studied, and derivatives were obtained.UV and mass
- Stankyavichyus, A. P.,Terent'ev, P. B.
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p. 1131 - 1134
(2007/10/02)
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- Oxidative Cyclizations. VII. Cyclization of 2-Substituted Anilines with Alkaline Hypohalite
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The Green-Rowe oxidation of 2-nitroanilines with alkaline hypohlorite, to yield benzofuroxans, is demonstrated by studies of the visible spectra of transient intermediates to proceed through N-chlorination and a singlet nitrene.Two variations on the route to the nitrene are possible.The cyclization step is represented as an internal capture of the nitrene by the ortho substituent, and on this basis the Green-Rowe oxidative cyclization is now extended to anilines whose ortho substituent is benzoyl or phenylazo.It is not however successful for ortho phenyl.Azo compounds were observed as byproducts in some of these reactions, and are shown to arise via N,N-dichloroanilines.
- Dyall, Leonard K.
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p. 2013 - 2026
(2007/10/02)
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- Thermal and Photochemical Transformations of 1-(Arylazo)-N-arylidene-2-naphthylamines
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1-(Arylazo)-N-arylidene-2-naphthylamines 3a-e, prepared by the reaction of 1-(arylazo)-2-naphthylamines 1a,b with aromatic aldehydes 2a-d on refluxing in toluene, gave the corresponding 1-(arylamino)-2-phenylnaphthimidazoles 6a-e in yields ranging between 50 and 60percent.Refluxing of 3a in o-dichlorobenzene, however, gave 1H-2-phenylnaphthimidazole (7, 45percent) and 2H-2-phenylnaphthotriazole (9, 5percent).Reaction of 3a with dimethyl acetylenedicarboxylate gave dimethyl benzoquinoxaline-2,3-dicarboxylate (10, 11percent), dimethyl-α-benzal-α'-imino>succinate (11, 7percent), dimethyl aminofumarate (12, 2percent), and benzanilide (13, 6percent).The reaction of 1-(phenylazo)-2-naphthylamine (1a) with DMAD, however, gave 10 (32percent) and 12 (3percent).Photolysis of 3a in benzene gave 2H-2-phenylnaphthotriazole (9, 5percent) and N-benzoyl-1-(phenylazo)-2-naphthylamine (19, 41percent), whereas the photolysis in methanol gave a mixture of 6a (10percent), 19 (25percent), 1a (1percent), and the naphthotriazole 9 (4percent).Reasonable mechanisms have been suggested for the formation of the various products in these reactions.
- Mitra, Abhijit,Chauhan, Shiv M. S.,George, M. V.
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p. 3182 - 3186
(2007/10/02)
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