- Positional Reactivity of Acylpolymethylbenzenes in Electrophilic Substitution
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Friedel-Crafts acylation, bromination, deuteration, and nitration of acetylpentamethylbenzene (APMB), 1-acetyl-2,3,4,6-tetramethylbenzene (ATMB), and 1-benzoyl-2,3,4,6-tetramethylbenzene (BTMB) and the resulting product distribution were investigated.Friedel-Crafts acylation, bromination, and deuteration of APMB and Friedel-Crafts acylation of ATMB gave deacetylation-substitution products.On the other hand, bromination and deuteration of ATMB (or BTMB) and Friedel-Crafts acylation of BTMB gave 5-substituted products.In both cases, the positional reactivities were in accordance with the relative ?-complex stability.Conversely, except for Friedel-Crafts-type nitration, the positional reactivities in the nitration of these substrates were strikingly different from those of the above three reactions.Thus, side-chain functionalization at the 6-methyl group occurred in nitration with fuming nitric acid, depending on the solvents in use.The NMDO calculations and the reaction of APMB with single-electron transfer reagents such as tetranitromethane-hν or cerium(IV) ammonium nitrate suggest that the product distribution in nitration can be explained in terms of a single-electron transfer mechanism.
- Matsuura, Kazunori,Kimura, Yasuo,Takahashi, Hisakazu,Morita, Toshio,Takahashi, Ichiro,et al.
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p. 757 - 765
(2007/10/02)
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- Ortho-Selective Side-Chain Nitration of α-Bromoacylpolymethylbenzenes and its Application to the Syntheses of Indan-1-one and Inden-1-one Derivatives
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α-Bromoacylpolymethylbenzenes 2a - m react with fuming nitric acid in acetic anhydride to give 2-(nitromethyl)-(α-bromoacyl)polymethylbenzenes 3a - m in good isolated yields.Compounds 3a - j undergo the intramolecular nucleophilic substitution/cyclization
- Keumi, Takashi,Matsuura, Kazunori,Nakayama, Norihiro,Tsubota, Toshiaki,Morita, Toshio,et al.
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p. 537 - 556
(2007/10/02)
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