Synthesis of polycyclic fused oxazolidin-2-ones by catalytic Boron (III)-Promoted oxo-Michael addition reaction and evaluation on their cytotoxicity

Oxazolidin-2-one served as a class of highly important nitrogen-containing five-membered heterocycles has been found in a wide range of biologically active molecules and chiral ligands. Consequently, its synthesis has attracted significant attention from chemists, leading to extensive investigations in this area. In this study, we developed a novel and more sustainable synthetic approach, using BF3 & sdot;Et2O as the catalyst to facilitate intramolecular oxo-Michael addition reactions of Boc-protected p-quinoamines. This approach allowed for the efficient construction of diverse polycyclic fused oxazolidin-2-one compounds and yields up to 98 %. Furthermore, the anti-tumor activity of these structurally unique oxazolidin-2-one derivatives was reported.