| Autor: |
Voronov, Aleksandr, Casnati, Alessandra, Mazzeo, Paolo P., Pelagatti, Paolo, Bacchi, Alessia, Mancuso, Raffaella, Gabriele, Bartolo, Motti, Elena, Maestri, Giovanni, Fehér, Péter Pál, Stirling, András, Ca', Nicola Della |
| Předmět: |
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| Zdroj: |
Advanced Synthesis & Catalysis; 5/23/2023, Vol. 365 Issue 10, p1646-1653, 8p |
| Abstrakt: |
Propargyl ureas can lead to a range of possible heterocyclic compounds, mainly depending on the employed catalyst. Silver salts are known to promote the N-5-exo-dig cyclization mode to imidazolidinone derivatives. Conversely, a versatile and stereoselective O-5-exo-dig cyclization of propargyl ureas to 2-aminooxazolines by Ag(I) catalysis is here disclosed. Good to excellent yields and complete stereoselectivity of the external double bond have been achieved under milder reaction conditions (50-60 °C). A one-pot protocol starting from the corresponding propargylic amines and isocyanates has been developed as well. N,N'-Dipropargyl ureas underwent a uncommon O-5-exo-dig/N-5-endo-dig double cyclization sequence. Finally, insights into the tautomeric equilibrium of 2-aminooxazoles and on their relative reactivity are provided. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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