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.
US7348148B2
申请人:——
公开号:US7348148B2
公开(公告)日:2008-03-25
Catalytic asymmetric cycloetherification via intramolecular oxy-Michael addition of enols
作者:Ryuichi Murata、Keisuke Asano、Seijiro Matsubara
DOI:10.1016/j.tet.2021.132381
日期:2021.9
compounds as oxygen nucleophiles. In particular, there are only a few reports on the oxy-Michael addition of the enol forms of carbonyl nucleophiles. In this study, we present the asymmetric cycloetherification of enols, which are generated in situ from enone-bearing ketones, using chiralbifunctionalorganocatalysts bearing amino and squaramide groups. This transformation chemo- and enantioselectively afforded