ChemInform Abstract: Bismuth Triflate‐L(‐)‐Proline Catalyzed Synthesis of Chiral 2,5‐Diaryl‐2,3‐dihydropyrano[2,3‐b]quinolin‐4‐ones.

Abstract

The synthesis of chiral (2R) 2,5-diaryl-2,3-dihydropyrano[2,3-b]quinolin-4-ones, was achieved, at ambient temperature, by the reaction of 3-acetyl-4-aryl-carbostyril and an aldehyde, in the presence of bismuth triflate–L(−)-proline complex, formed in situ. The products were obtained in 62–78% yield with high enantioselectivity (72–96% ee). J. Heterocyclic Chem., (2011).