摘要
The chiral N-heterocyclic carbene-catalyzed [4 ＋ 2] annulation of a-chloroaldehydes and aurones was developed, giving the corresponding benzofuran–fused dihydropyranones in good to high yields with good diastereoselectivities and excellent enantioselectivities. The catalytic cycle features with the generation of enolate from chloroaldehdye and its following [4 ＋ 2] cycloaddtion with aurones.
The chiral N-heterocyclic carbene-catalyzed [4 ＋ 2] annulation of a-chloroaldehydes and aurones was developed, giving the corresponding benzofuran–fused dihydropyranones in good to high yields with good diastereoselectivities and excellent enantioselectivities. The catalytic cycle features with the generation of enolate from chloroaldehdye and its following [4 ＋ 2] cycloaddtion with aurones.
基金
The Financial support from the National Natural Science Foundation of China (Nos. 21425207, 21521002)
the Chinese Academy of Sciences is greatly acknowledged
