- Tert -Butyl nitrite promoted transamidation of secondary amides under metal and catalyst free conditions
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A mild and efficient method is demonstrated for the transamidation of secondary amides with various amines including primary, secondary, cyclic and acyclic amines in the presence of tert-butyl nitrite. The reaction proceeds through the N-nitrosamide intermediate and provides the transamidation products in good to excellent yields at room temperature. Moreover, the developed methodology does not require any catalyst or additives.
- Sureshbabu, Popuri,Azeez, Sadaf,Chaudhary, Priyanka,Kandasamy, Jeyakumar
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p. 845 - 850
(2019/01/30)
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- Tert-Butyl Nitrite-Mediated Synthesis of N-Nitrosoamides, Carboxylic Acids, Benzocoumarins, and Isocoumarins from Amides
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This work reports tert-butyl nitrite (TBN) as a multitask reagent for (1) the controlled synthesis of N-nitrosoamide from N-alkyl amides, (2) hydrolysis of N-methoxyamides to carboxylic acids, (3) metal- and oxidant-free benzocoumarin synthesis from ortho-aryl-N-methoxyamides via N-H, C-N, and C-H bond activation, and (4) isocoumarin synthesis using Ru(II)/PEG as a recyclable catalytic system via ortho-C-H activation and TBN as an oxygen source. The sequential functional group interconversion of amide to acid has also been examined using IR spectroscopic analysis. Additionally, this methodology is highly advantageous due to short reaction time, gram scale synthesis, and broad substrate scope.
- Yedage, Subhash L.,Bhanage, Bhalchandra M.
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p. 5769 - 5781
(2017/06/07)
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- A Study of Essentially Free Carbocations Derived via Diazonium and Oxo Diazonium Ions in the Liquid Phase
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Nitrogen- and nitrous oxide-separated ion pairs containing 4-substituted benzyl cations and carboxylate or tosylate anions were prepared by thermolysis of N-nitroso- and N-nitroamides, acidification of phenyldiazomethane, and nitrosation of N-benzyl-O-benzoylhydroxylamine. The cations were generated in benzene/toluene and benzene/anisole mixtures and were found to partition between the counterion and the solvent and between the aromatic cosolvent and benzene. A familial relationship among the methods was observed. As the cation became more reactive, the yield of solvent-derived products (SDPs) rose and the ratio of rate constants for its reaction with toluene versus benzene, kT/kB, fell. The yield of SDP also rose as the temperature was decreased and as N2 was replaced by N2O; however, kT/kB remained unchanged. Inert diluents had no effect on kT/kB but decreased hydrocarbon yield by 40% on 2-fold dilution. In the presence of reactive diluents that are converted into secondary alkylating agents, both the % hydrocarbon and kT/kB rose. These results are interpreted in terms of the intermediacy of inert-molecule-separated ion pairs (IMSIPs) in deamination. The cation reacted with benzoates and tosylates not only at the oxygens but also at the ipso carbon; subsequent decarboxylation and desulfonylation, respectively, led to diphenylmethanes. The ester/SDP ratio is introduced as a new measure of carbocation reactivity.
- Darbeau, Ron W.,White, Emu H.,Song, Fenhong,Darbeau, Nyla R.,Chou, James
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p. 5966 - 5978
(2007/10/03)
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- Reaction of amides with nitric oxide (NO)
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Amides were allowed to react with nitric oxide in aprotic and non- ethereal solvents to give the corresponding N-nitroso derivatives. The reaction was accelerated by addition of oxygen. The solvent effect revealed that the reaction did not proceed in the presence of protic media.
- Itoh, Takashi,Nagata, Kazuhiro,Matsuya, Yuji,Miyazaki, Michiko,Ohsawa, Akio
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p. 5017 - 5020
(2007/10/03)
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- Reaction of N-Aryl- and N-Alkyl-benzimidoyl Chlorides with Silver Nitrate
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N-Arylbenzimidoyl chlorides, in which the N-aryl group is unsubstituted at the ortho- and para-positions, react with AgNO3 to yield N-(nitroaryl)benzamides, in which the NO2 group resides in the ortho- or para-position.N-Arylbenzimidoyl chlorides, in which the N-aryl ring is 2,4,6-trisubstituted, react with AgNO3 to yield the corresponding N-aryl-N-nitrobenzamides.The formation of both types of product can be explained by the intermediacy of an O-nitro imidate.Spectroscopic and chemical evidence is presented for the formation of this intermediate in the reaction of N-(2,4,6-trisubstituted phenyl)benzimidoyl chlorides with AgNO3.Rearrangement of the O-nitro imidate is unimolecular and intramolecular.The rate of rearrangement is independent of the substituent in the C-aryl ring, but increases with the electon-withdrawing ability of the substituents in the N-aryl ring.A mechanism is proposed in which the imidoyl chloride reacts with AgNO3 to produce first a nitrilium ion which goes on to form an O-nitro imidate that subsequently rearranges via a homolytic cleavage of the O-NO2 bond.The ortho:para ratios of N-(nitroaryl)benzamides obtained in the present work indicate that O-nitro imidates are not responsible for the high 1/2ortho:para ratios sometimes observed in the nitration of anilides.N-Alkylbenzimidoyl chlorides react with AgNO3 to form the corresponding N-nitro- and N-nitrosobenzamides.The mechanism of formation of the N-alkyl-N-nitrobenzamide arises from a pathway analogous to that for N-aryl-N-nitrobenzamides, involving a nitrilium ion that gives rise to an O-nitro imidate.The evidence for the formation of the N-nitrosobenzamide points to an alternative reaction of the imidoyl chloride with AgNO3.One possible mechanism for this reaction is described.
- Iley, Jim,Carvalho, Emilia,Norberto, Fatima,Rosa, Eduarda
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p. 281 - 290
(2007/10/02)
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