- Paired electrochemical conversion of nitroarenes to sulfonamides, diarylsulfones and bis(arylsulfonyl)aminophenols
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A paired electrochemical method using nitrobenzene (NB) derivatives and arylsulfinic acids (ASAs) as starting materials was developed for the synthesis of some new sulfonamides, diarylsulfones and bis(arylsulfonyl)aminophenols. The synthetic strategy was designed using the data provided by electrochemical studies involving cyclic voltammetry on NB oxidation in the absence and presence of ASAs. The reactions have been successfully performed in an undivided cell, at carbon rod electrodes, in aqueous solutions, by constant current electrolysis at room temperature. This strategy does not require catalysts, toxic solvents and challenging workups. It is also applicable for a wide range of nitroarenes.
- Mokhtari, Banafsheh,Nematollahi, Davood,Salehzadeh, Hamid
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p. 1499 - 1505
(2018/04/12)
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- Hydroxamic Acids as Chemoselective (ortho-Amino)arylation Reagents via Sigmatropic Rearrangement
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The use of readily available hydroxamic acids as reagents for the chemoselective (ortho-amino)arylation of amides is described. This reaction proceeds under metal-free, mild conditions, displays a very broad scope, and constitutes a direct approach for the metal-free attachment of aniline residues to carbonyl derivatives.
- Shaaban, Saad,Tona, Veronica,Peng, Bo,Maulide, Nuno
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supporting information
p. 10938 - 10941
(2017/08/30)
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- Flow cell electrosynthesis of phenylhydroxylamines. In situ reaction with arenesulfonyl chlorides. A convenient route to arenesulfinic acids synthesis.
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First, electrosyntheses of phenylhydroxylamines in a flow cell fitted with porous cathode and two counter-electrodes are described.Good yields are attained when electrolyses are performed in buffered aqueous organic or aqueous media.Reaction between p-toluenesulfonyl chloride and N-(3-chloro-4-methylphenyl)hydroxylamine, at the outlet of the cell, leads to a N-sulfonylated phenylhydroxylamine (N-addition); hydrolysis of this latter occurs in aqueous basic media to give the corresponding nitrosobenzene and sodium p-toluenesulfinate.As a result, some arenesulfinic acids have been directly obtained after reaction of arenesulfonyl chloride with sodium salt of 3-hydroxylaminobenzoate and 3-hydroxylaminobenzenesulfonate in aqueous phosphate buffer (pH 7).Next, an examination of the reaction of p-toluenesulfonyl chloride with phenylhydroxylamine in organic solvent, in the presence of triethylamine or of sodium carbonate, shows the importance of experimental conditions to control N-addition or O-addition.Addition of some arenesulfonyl chlorides to phenylhydroxylamine, in ether or dichloromethane containing sodium carbonate, gives only the N-sulfonylated phenylhydroxylamines.These compounds lead to nitrosobenzene and arenesulfinate anions in aqueous basic media.Aliphatic or aromatic sulfinic acids can be prepared in this way.
- Moinet, C.,Raoult, E.
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p. 214 - 221
(2007/10/02)
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