Asymmetric Organocatalyzed Cascade Reactions-Merging the pseudo-Halogen and Halogen Effect with Dienamine Catalysis

The combination of asymmetric organocatalysis with the (pseudo)-halogen effect enables the formation of chiral norcarane scaffolds in high yields and selectivities (up to 92% yield, > 99% ee, and > 95:5 d.r.). This was achieved by reacting (pseudo)-halogenated 3-vinyl chromones with in situ generated chiral dienamines in an inverse electron demand [4 + 2] cycloaddition followed by an intramolecular SN2 reaction. These scaffolds could easily undergo photoinduced rearrangements or lactonization to form intricate chiral ring structures.

Automated summary

The combination of asymmetric organocatalysis with the (pseudo)-halogen effect allows for the efficient formation of chiral norcarane scaffolds. These scaffolds can easily undergo rearrangements or lactonization to form intricate chiral ring structures.