Reactivity of lithium β‑ketocarboxylates: the role of lithium salts
Autor: | Mateo Berton, Rossella Mello, María Elena González-Núñez, Paul G. Williard |
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Rok vydání: | 2017 |
Předmět: |
chemistry.chemical_classification
010405 organic chemistry Chemistry Inorganic chemistry Halide chemistry.chemical_element Disproportionation General Chemistry 010402 general chemistry 01 natural sciences 7. Clean energy Biochemistry Nitrogen Catalysis 0104 chemical sciences Hydrolysis Colloid and Surface Chemistry Polymer chemistry Reactivity (chemistry) Lithium Inert gas Química orgànica Alkyl |
Zdroj: | Berton, Mateo Otao Mello, Rossella C. C. Williard, Paul G. González Núñez, María Elena 2017 Reactivity of lithium β‑ketocarboxylates: the role of lithium salts Journal of the American Chemical Society 139 48 17414 17420 RODERIC. Repositorio Institucional de la Universitat de Valéncia instname |
Popis: | Lithium beta-ketocarboxylates 1(COOLi), prepared by the reaction of lithium enolates 2(Li+) with carbon dioxide, readily decarboxylate in THF solution unless in the presence of lithium salts, in which case they are indefinitely stable at room temperature in inert atmosphere. The availability of stable THF solutions of lithium beta-ketocarboxylates 1(COOLi) in the absence of carbon dioxide allowed reactions to take place with nitrogen bases and alkyl halides 3 to give alpha-alkyl ketones 1(R) after acidic hydrolysis. The sequence thus represents the use of carbon dioxide as a removable directing group for the selective monoalkylation of lithium enolates 2(Li+). The roles of lithium salts in preventing the decarboxylation and disproportionation reactions of lithium beta-ketocarboxylates 1(COOLi), and in determining the course of the reaction with bases and alkyl halides 3, are discussed. |
Databáze: | OpenAIRE |
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