RESUMO
A copper-catalyzed intramolecular asymmetric double C-arylation reaction was developed. The method provides a facile approach to chiral spiro bis-oxindoles in high yields and with good to excellent enantioselectivities. It also shows a broad substrate scope and good functional group tolerance. Density functional theory (DFT) calculations were conducted and revealed that the enantioselectivity is determined at the oxidative addition of Cu(I) into the second C-I bond.
RESUMO
A stereospecific synthesis of ( E)-5-tetrasubstituted-ylidene-3,5-dihydro-4 H-imidazol-4-one derivatives is demonstrated through a cascade process by combination of a Michael addition and Boulton-Katritzky rearrangement. The method provides a simple and efficient approach for the synthesis of ( E)-5-tetrasubstituted-ylidene-3,5-dihydro-4 H-imidazol-4-ones from the reactions of N-(isoxazol-3-yl)-propiolamides or N-(1,2,4-oxadiazo-3-yl) propiolamides with N or C nucleophiles.