Orientation in Aromatic Nitration Reactions<sup>1</sup>

Roberts, John D.; Sanford, Janet K.; Sixma, F. L. J.; Cerfontain, H.; Zagt, R.

doi:10.1021/ja01647a005

Cited by 37 publications

(16 citation statements)

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“…5). op = ojp + vr (4) Electrophilic reactions provide far greater opportunity for resonance contributions by the substituent. The difference in the and +values is attributed to such resonance (Table III).…”

Section: IVmentioning

confidence: 99%

A Quantitative Treatment for Electrophilic Reactions of Aromatic Derivatives^1-3

Okamoto¹,

Brown²

1957

J. Org. Chem.

185

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Section: IVmentioning

confidence: 99%

A Quantitative Treatment for Electrophilic Reactions of Aromatic Derivatives^1-3

Okamoto¹,

Brown²

1957

J. Org. Chem.

185

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“…Furthermore, the observed product distribution is in semiquantitative agreement with that predicted from the nitration of chlorobenzene and o-xylene in acetic anhydride, assuming additivity of substituent effects. From the data of Roberts et al (14) for chlorobenzene together with the observation of Perrin and Skinner (2) that the reactivity of the position @so to chlorine is similar to that of the meta position, and the data of Fischer et al (15) for o-~ylene,~ the relative reactivities of the nuclear of 1-chloro-2,3-dimethylbenzene are calculated to be, in order from C-l t o C-6: 0, 38, l , 42, 1, 18. The observed yields of products resulting from attack at these sites are: 0, 29, 0, 46, 5, 20.…”

Section: Introductionmentioning

confidence: 99%

Nitration of 1-chloro-2,3-dimethylbenzene in acetic anhydride. Formation and rearomatization of adducts

Fischer¹,

Greig²

1978

Can. J. Chem.

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. Nitration of 1-chloro-2,3-dimethylbenzene in acetic anhydride gives the cis and trarzs isomers of 3-chloro-4,5-dimethyl-4-nitrocyclohexa-2,5-dienyl acetate (29%) and 1-chloro-2,3-dimethyl-4-nitro-(46%), -5-nitro-(573, and -6-nitrobenzene (20%). In formic acid and acidified methanol, exchange of acetate for formate and methoxyl, respectively, occurs and the diastereoisomers of 3-chloro-4,5-dimethyl-4-nitrocyclohexa-2,5-dienyl formate and methyl ether, respectively, are formed. Rearomatization of each isomer of 3-chloro-4,5-dimethyl-4-nitrocyclohexa-2,5-dienyl acetate in acetic acid results in initial isomerization t o form the pair of diastereoisomers and subsequent elimination of nitrous acid to form 3-chloro-4,5-dimethylphenyl acetate. In 25% trifluoroacetic acid in deuteriochloroform elimination of acetic acid and migration of the nitro group to form 1-chloro-2,3-dimethyl-4-nitro-benzene and a lesser amount of its 6-nitro isomer is the dominant reaction. In the presence of mesitylene the formation of the nitro derivatives is suppressed and 3'-chloro-2,4,4',5',6-pentamethylbiphenyl is obtained. It is proposed that cyclohexadienyl cations are significant intermediates in all of the reactions. Pyrolysis of the adducts gives 1-chloro-2,3-dimethylbenzene as the major product.

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“…Can the HO–arene interaction override bromine’s deactivation? We were gratified to find that nitration of 7 also proceeds exclusively on the brominated ring (in addition to nitrate ester formation: Figure S2) ( 8 ). , In fact, we found that the nitrate ester forms prior to arene nitration (see the SI). It is noteworthy that an electron-deficient oxygen atom, as part of a nitrate ester, can direct EAS.…”

mentioning

confidence: 99%

Through-Space Activation Can Override Substituent Effects in Electrophilic Aromatic Substitution

et al. 2017

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Electrophilic aromatic substitution (EAS) represents one of the most important classes of reactions in all of chemistry. One of the "iron laws" of EAS is that an electron-rich aromatic ring will react more rapidly than an electron-poor ring with suitable electrophiles. In this report, we present unique examples of electron-deficient arenes instead undergoing preferential substitution in intramolecular competition with more electron-rich rings. These results were made possible by exploiting the heretofore unknown propensity of a hydrogen-bonding OH-arene interaction to switch to the alternative HO-arene interaction in order to provide activation. In an extreme case, this through-space HO-arene activation is demonstrated to overcome the deactivating effect of a trifluoromethyl substituent, making an otherwise highly electron-deficient ring the site of exclusive reactivity in competition experiments. Additionally, the HO-arene activation promotes tetrabromination of an increasingly more electron-deficient arene before the unactivated "control" ring undergoes monobromination. It is our hope that these results will shed light on biological interactions as well as provide new strategies for the electrophilic substitution of aromatic rings.

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Orientation in Aromatic Nitration Reactions¹

Cited by 37 publications

References 0 publications

A Quantitative Treatment for Electrophilic Reactions of Aromatic Derivatives^1-3

A Quantitative Treatment for Electrophilic Reactions of Aromatic Derivatives^1-3

Nitration of 1-chloro-2,3-dimethylbenzene in acetic anhydride. Formation and rearomatization of adducts

Through-Space Activation Can Override Substituent Effects in Electrophilic Aromatic Substitution

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Orientation in Aromatic Nitration Reactions1

Cited by 37 publications

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A Quantitative Treatment for Electrophilic Reactions of Aromatic Derivatives1-3

A Quantitative Treatment for Electrophilic Reactions of Aromatic Derivatives1-3

Nitration of 1-chloro-2,3-dimethylbenzene in acetic anhydride. Formation and rearomatization of adducts

Through-Space Activation Can Override Substituent Effects in Electrophilic Aromatic Substitution

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Orientation in Aromatic Nitration Reactions¹

A Quantitative Treatment for Electrophilic Reactions of Aromatic Derivatives^1-3

A Quantitative Treatment for Electrophilic Reactions of Aromatic Derivatives^1-3