摘要
The proline based chiral organocatalyst has been found to be an efficient catalyst for the facile synthesis of substituted 2-aryl-2 H-chromenes-3-carbaldehyde. We envisioned that the iminium interaction between chiral amino catalysts and a,b-unsaturated carbonyl group was beneficial along with thiourea group as hydrogen bond donor, heterocyclic amines as general base in the domino oxa-Michael-aldol reaction. This catalytic system provided the products in good to high yields（73%–96%） with excellent enantioselectivity（up to 97%） and reasonable reaction time. The atom economy, high yield and mild reaction conditions are some of the important features of this protocol.
The proline based chiral organocatalyst has been found to be an efficient catalyst for the facile synthesis of substituted 2-aryl-2 H-chromenes-3-carbaldehyde. We envisioned that the iminium interaction between chiral amino catalysts and a,b-unsaturated carbonyl group was beneficial along with thiourea group as hydrogen bond donor, heterocyclic amines as general base in the domino oxa-Michael-aldol reaction. This catalytic system provided the products in good to high yields（73%–96%） with excellent enantioselectivity（up to 97%） and reasonable reaction time. The atom economy, high yield and mild reaction conditions are some of the important features of this protocol.
