Unexpected intramolecular nucleophilic cyclization of ureidoacetamide: A novel route towards the synthesis of 2,4,5-trisubsituted oxazoles
| Autor: | Dong Yawen, Mustafa Hussain, Guanglan Li, Xiangting Min, Jianhui Liu |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
010405 organic chemistry
Organic Chemistry Condensation chemistry.chemical_element 010402 general chemistry 01 natural sciences Biochemistry Medicinal chemistry 0104 chemical sciences chemistry.chemical_compound Nucleophile chemistry Intramolecular force Reagent Amide Drug Discovery Electrophile Potassium cyanate Carbon |
| Zdroj: | Tetrahedron Letters. 60:1691-1695 |
| ISSN: | 0040-4039 |
| DOI: | 10.1016/j.tetlet.2019.05.028 |
| Popis: | A variety of N, 2-diaryl-2-ureidoacetamide prepared from the condensation of N-aryl-α-aminoamide with potassium cyanate (KOCN) undergo efficient Hendrickson’s reagent-mediated nucleophilic cyclization to afford 2,5-diamine-4-aryloxazoles. The two-step synthesis provides seven target products in yields of 61–78% under mild conditions. This reaction involves an unusual pathway in which the electrophilic amide carbonyl carbon is activated by Hendrickson’s reagent and attacked by a nucleophilic ureido oxygen in a 5-exo-trig O-cycloisomerization. |
| Databáze: | OpenAIRE |
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