Direct Addition of Grignard Reagents to Aliphatic Carboxylic Acids Enabled by Bulky
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‐Organomagnesium Anilides
作者:Kilian Colas、A. Catarina V. D. dos Santos、Stefanie V. Kohlhepp、Abraham Mendoza
DOI:10.1002/chem.202104053
日期:2022.2.16
Adding the right amount: The addition of Grignard nucleophiles to carboxylic acids is made difficult by the lower nucleophilicity of these abundant organometallics, the low electrophilicity of carboxylate anions, and the faster over-addition to any ketones produced. Herein we introduce a simple magnesium anilide additive that enhances the nucleophilicity of Grignardreagents towards aliphatic carboxylates
Mise en évidence d'une réactivité spécifique des trifluorométhylcétones vis-à-vis du bromure d'allylmagnésium
作者:Caroline Felix、André Laurent、Pierre Mison
DOI:10.1016/0022-1139(94)03097-j
日期:1995.1
report on an unusual reactivity of allylmagnesiumbromide. This Grignard reagent acts as a reducing agent towards trifluoromethylated ketones. A single electron transfer is suggested to explain the reductive process. By using an excess of allylmagnesiumbromide, an exclusive addition reaction is obtained. The stereochemistry of both addition and reduction reactions is discussed.
Total Syntheses of Conformationally Locked Difluorinated Pentopyranose Analogues and a Pentopyranosyl Phosphate Mimetic
作者:Jonathan A. L. Miles、Lisa Mitchell、Jonathan M. Percy、Kuldip Singh、E. Uneyama
DOI:10.1021/jo0620258
日期:2007.3.1
Trifluoroethanol has been elaborated, via a telescoped sequence involving a metalated difluoroenol, a difluoroallylic alcohol, [2,3]-Wittig rearrangement, and ultimately an RCM reaction and requiring minimal intermediate purification, to a number of cyclooctenone intermediates. Epoxidation of these intermediates followed by transannular ring opening or dihydroxylation, then transannular hemiacetalization delivers novel bicyclic analogues of pentopyranoses, which were elaborated (in one case) to an analogue of a glycosyl phosphate.