- Vicarious Nucleophilic Substitution of Hydrogen in Nitroarenes with Carbanions of α-Haloalkyl Phenyl Sulfones
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Carbanions of α-chloroalkyl phenyl sulfones and N,N-dialkyl-α-chloroalkanesulfonamides react with nitrobenzenes to effect direct nucleophilic replacement of hydrogen ortho and para to the nitro group, with vicarious loss of chloride anion, to give the corresponding nitrobenzylsulfonyl derivatives.The reaction occurs much more rapidly than the replacement of such good leaving groups as halogen, methoxy, and phenoxy.Most substituents in the nitrobenzene ring do not interfere with the reaction.The effect of substituents in the nitrobenzene and the carbanion on the orientation of the substitution is discussed.
- Makosza, Mieczyslaw,Golinski, Jerzy,Baran, Janusz
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p. 1488 - 1494
(2007/10/02)
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- SPECIFIC ORTHO ORIENTATION IN THE VICARIOUS SUBSTITUTION OF HYDROGEN IN AROMATIC NITRO COMPOUNDS WITH CARBANION OF CHLOROMETHYL PHENYL SULFONE
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Vicarious nucleophilic substitution of hydrogen atoms in nitroarenes with chloromethylphenyl sulfone proceeds selectively ortho to the nitro group when carried out in t-BuOK/THF base/solvent system.In the majority of 3-substituted nitrobenzene derivatives substitution occurs at the most hindered position 2.These conditions offer an efficient method of synthesis of 2,6 and 2,3-disubstituted nitrobenzene derivatives.
- Makosza, M.,Glinka, T.,Kinowski, A.
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p. 1863 - 1868
(2007/10/02)
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- On the Mechanism of the Vicarious Nucleophilic Substitution of Hydrogen in Nitroarenes
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On the basis of the isotope effect and the effect of base on the reaction rate the main features of the mechanism of the vicarious nucleophilic substitution of hydrogen were established.The reaction proceeds via fast and reversible addition of the carbanions to the nitroarenes followed by slower base-induced β-elimination.
- Makosza, Mieczyslaw,Glinka, Tomasz
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p. 3860 - 3861
(2007/10/02)
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