N-fluorobis[(trifluoromethyl)sulfonyl]imide: an efficient reagent for the .alpha.-fluorination of functionalized carbonyl compounds
摘要:
The N-fluorobis[(trifluoromethyl)sulfonyl]imide (1) has been used in the electrophilic fluorination of the lithium enolate of esters, amides, and ketones. The corresponding alpha-fluorocarbonyl compounds have been obtained in good yields. The alpha-fluorination of beta-diesters, beta-diamides, beta-keto esters, and beta-diketones has been performed either on the neutral compounds or on the metal enolates. In this way some geminal azafluoro, chlorofluoro, fluorooxy compounds have been prepared in nearly quantitative yields. Also some alpha-keto esters and acids have been selectively monofluorinated in the beta-position by simple treatment of the neutral compound with 1.
Enantioselective Enolate Protonation with Chiral Anilines: Scope, Structural Requirements, and Mechanistic Implications
作者:E. Vedejs、A. W. Kruger、N. Lee、S. T. Sakata、M. Stec、E. Suna
DOI:10.1021/ja994437m
日期:2000.5.1
substitution at the γ-carbon, γ-protonation can be a competing reaction in the case of the aliphatic substrates 12, 14b, 14d, and 18. The evidence is most consistent with a mechanism that involves proton transfer from 1a to a mixed aggregate consisting of enolate 4a and the lithiated amide 5, but direct proton transfer from 1a to the enolate is not ruled out.