Intramolecular Nitrone Cycloaddition of α-(Trifluoromethyl)styrenes. Role of the CF3 Group in the Regioselectivity
| Autor: | María Sánchez-Roselló, Fernando Rabasa-Alcañiz, Carlos del Pozo, Marcos Escolano, Santos Fustero, Amparo Asensio |
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| Rok vydání: | 2017 |
| Předmět: |
Steric effects
chemistry.chemical_classification Trifluoromethyl Bicyclic molecule 010405 organic chemistry Stereochemistry Organic Chemistry Regioselectivity 010402 general chemistry 01 natural sciences Cycloaddition 0104 chemical sciences Nitrone chemistry.chemical_compound chemistry Intramolecular force Moiety |
| Zdroj: | The Journal of Organic Chemistry. 82:2505-2514 |
| ISSN: | 1520-6904 0022-3263 |
| DOI: | 10.1021/acs.joc.6b02880 |
| Popis: | The intramolecular 1,3-dipolar cycloaddition of ortho-substituted 1,1,1-trifluoromethylstyrene-derived nitrones is described. Tricyclic fused isoxazolidines were obtained as major or exclusive products, in contrast to the case for nonfluorinated substrates, which rendered the bridged derivatives. This change in the regioselectivity was attributed to the electronic and, particularly, steric requirements of the trifluoromethyl group in comparison to the methyl group. It is worth mentioning that trifluoromethylstyrenes have been employed for the first time as dipolarophiles in a 1,3-dipolar intramolecular cycloaddition reaction, leading to the corresponding isoxazolidines bearing a quaternary trifluoromethyl moiety. Finally, the synthetic utility of the developed methodology has been illustrated with the synthesis of a family of bicyclic fluorinated 1,3-amino alcohols. |
| Databáze: | OpenAIRE |
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