Divergent Reactivity of N-Isocyanates with Primary and Secondary Amines: Access to Pyridazinones and Triazinones
| Autor: | Joshua S. Derasp, Andre M. Beauchemin, Jean-François Vincent-Rocan |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
chemistry.chemical_classification
Primary (chemistry) Ketone Molecular Structure Triazines 010405 organic chemistry Organic Chemistry 010402 general chemistry 01 natural sciences Biochemistry Catalysis 0104 chemical sciences Pyridazines Nucleophile chemistry Cyclization Molecule Organic chemistry Reactivity (chemistry) Amine gas treating Amines Physical and Theoretical Chemistry Isocyanates |
| Zdroj: | Organic Letters. 18:658-661 |
| ISSN: | 1523-7052 1523-7060 |
| DOI: | 10.1021/acs.orglett.5b03590 |
| Popis: | Cascade reactions for the synthesis of 1,2,4-triazinones and 5-aminopyridazinones are reported using α-ketocarbazones as N-isocyanate precursors and exploiting the divergent reactivity observed with primary and secondary amines. Triazinones were formed with primary amines, likely through addition of the amine on the N-isocyanate, followed by cyclization (condensation) on the ketone. In contrast, such cyclization is impossible for secondary amines; this allows in situ formation of enamines, which, upon cyclization, generate 5-amino pyridazinones. This sequence further illustrates the versatility of N-isocyanates in heterocyclic synthesis and provides a rare example of carbon nucleophiles reacting with N-isocyanates. |
| Databáze: | OpenAIRE |
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