Generation of oxindole-2-thiones (thiols) via dilithiated<i>N</i>-<i>tert</i>-Boc-anilines. Synthesis of a sulfur analog of MK886

Cervantes, A.; Contreras, Claudia; Guzmán, A.; Vale, E. E.; Velarde, E.; Berthiaume, Sylvie; Muchowski, Joseph M.

doi:10.1139/v95-045

Cited by 8 publications

(3 citation statements)

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“…42 Most other reports of lithiation of 2-substituted N-acylanilines deal with 2-alkyl substituents. [55][56][57][58][59][60] Modest yields of the corresponding 6-substituted products 53h and 54h were reported for 2-isopropylphenylcarbamate and N-(2isopropylphenyl)pivalamide compounds, respectively, and Figure 8 for the structures of the actual products formed in these cases. f According to NMR of the crude reaction mixture.…”

Section: Short Review Syn Thesismentioning

confidence: 99%

“…60 Lithiations of the 2-methylphenyl derivatives 50e, 51e, and 52e and 2-ethylphenyl derivatives 50f and 51f, however, take a completely different course, since the methyl or ethyl groups offer more favorable sites for lithiation. 50,[55][56][57][58][59] For example, treatment of the lithiated derivative of 50e with a ketone gives rise to the corresponding products 56 substituted at the benzylic position (Scheme 8). 55,56 In a similar way, treatment of the lithiated intermediates with dimethylformamide gives rise to the products 57 and 58.…”

Section: Short Review Syn Thesismentioning

confidence: 99%

“…55,56 In a similar way, treatment of the lithiated intermediates with dimethylformamide gives rise to the products 57 and 58. 58 This preferential lateral lithiation is an important process in its own right.…”

Section: Short Review Syn Thesismentioning

confidence: 99%

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Unravelling Factors Affecting Directed Lithiation of Acylaminoaromatics

2018

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Ureas, pivalamides, and carbamates are widely used as directing metalation groups (DMGs) due to their good directing ability, low cost, ease of access, and ease of removal. Lithiation of substituted benzenes having such directing metalation groups using various alkyllithiums in anhydrous solvent at low temperature provides the corresponding lithium intermediates, but lithiation may take place at various sites. Reactions of the lithium reagents obtained in situ with various electrophiles give the corresponding derivatives, typically substituted at the site(s) where initial lithiation occurred, often in high yields. However, it is often difficult to predict what reagents and/or conditions might be needed to give specific products or to draw general conclusions about the factors that influence the reactions, especially when the reagents, temperature, and solvents used in reported reactions are not directly comparable. In this review, therefore, we attempt to unravel the various factors that influence the lithiation of various simple aromatic compounds containing urea, pivalamide, and carbamate groups.1 Introduction2 Lithiation with DMG Attached Directly to the Phenyl Ring2.1 Influence of the DMG2.2 Influence of Substitution on the Phenyl Ring3 Lithiation with the DMG Separated by a CH2 Group from the Phenyl Ring3.1 Effect of the DMG3.2 Influence of Substitution on the Phenyl Ring4 Lithiation with the Phenyl Ring and DMG Separated by Two or More CH2 Groups4.1 Effect of the DMG and Its Distance from the Phenyl Group4.2 Effect of Substituents on the Phenyl Ring5 Conclusions

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