The cyclization-carbonylation-cyclizationcouplingreaction (CCC-coupling reaction) of propargyl ureas catalyzed by Pd(II)(box) complexes afforded symmetrical ketones bearing two 2-amino-2-oxazoline groups in good to moderate yields.
Unexpected Stereoselective Access to 2‐Aminooxazolines from Propargyl Ureas by Silver Salts under Mild Conditions
作者:Aleksandr Voronov、Alessandra Casnati、Paolo P. Mazzeo、Paolo Pelagatti、Alessia Bacchi、Raffaella Mancuso、Bartolo Gabriele、Elena Motti、Giovanni Maestri、Péter Pál Fehér、András Stirling、Nicola Della Ca'
DOI:10.1002/adsc.202200950
日期:——
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