Acid–base-sensitive allylic oxidation of 2-allylbenzoic acids to form phthalides
| Autor: | Thi Anh Hong Nguyen, Le Thi Ngoc Chuc, Duen Ren Hou |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
chemistry.chemical_classification
Allylic rearrangement Base (chemistry) White catalyst Organic Chemistry Isocoumarins chemistry.chemical_element Biochemistry chemistry.chemical_compound chemistry Kinetic isotope effect Organic chemistry Physical and Theoretical Chemistry Isomerization Benzoic acid Palladium |
| Zdroj: | Organic & Biomolecular Chemistry. 18:2758-2768 |
| ISSN: | 1477-0539 1477-0520 |
| DOI: | 10.1039/d0ob00303d |
| Popis: | Allylic oxidation of 2-allylbenzoic acids to phthalides, instead of Wacker-type isocoumarins, was achieved with 1,2-bis(phenylsulfinyl)ethane palladium(ii) acetate (White catalyst) and oxygen in DMSO. The selective formation of 3-ethylidenephthalides or 3-vinylphthalides was controlled by the addition of acids or bases, and the reaction conditions were applied to substituted 2-allylbenzoic acids to generate corresponding phthalides selectively. Mechanistic studies, including the corresponding reaction of (E)-2-(1-propenyl)benzoic acid to 3-methylisocoumarin, isomerization reaction of 3-vinylphthalide to 3-ethylidenephthalide, and the kinetic isotope effect using 2-(1,1-d2-allyl)benzoic acid, revealed the competition between Wacker-type oxidation and allylic C-H cleavage, which is the key step to generating phthalides. A natural product, 3-ethyl-6-hydroxyphthalide, was prepared by this method. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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