Base and catalyst-free synthesis of nitrobenzodiazepines via a cascade N-nitroallylation-intramolecular aza-Michael addition involving o-phenylenediamines and nitroallylic acetates
| Autor: | Divya K. Nair, Sudheesh T. Sivanandan, Irishi N. N. Namboothiri, Pravin S. Kendrekar |
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| Rok vydání: | 2019 |
| Předmět: |
chemistry.chemical_classification
Annulation Base (chemistry) 010405 organic chemistry Chemistry education Organic Chemistry 010402 general chemistry 01 natural sciences Biochemistry Medicinal chemistry 0104 chemical sciences Catalysis Intramolecular force Yield (chemistry) Drug Discovery Michael reaction SN2 reaction Reactivity (chemistry) |
| Zdroj: | Tetrahedron. 75:130761 |
| ISSN: | 0040-4020 |
| DOI: | 10.1016/j.tet.2019.130761 |
| Popis: | A [4+3] annulation of o-phenylenediamines with primary nitroallylic acetates affords nitrobenzodiazepines (NBDZs) in good to excellent yield. The reaction which proceeds in MeOH at room temperature in the absence of any base or catalyst involves a cascade SN2 N-nitroallylation-intramolecular aza-Michael addition sequence. In the case of mono-N-arylated o-phenylenediamines and o-aminobenzamides, the reaction stops at the SN2 stage affording nitroallylic amines. On the other hand, reaction of o-aminobenzamides with secondary nitroallylic acetates delivers SN2′ products. Formation of stable SN2 and SN2′ products provides insights into the reactivity of primary and secondary nitroallylic acetates and also the mechanism of formation of nitrobenzodiazepines. |
| Databáze: | OpenAIRE |
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