Organocatalytic Asymmetric Domino Oxa-Michael–Mannich-[1,3]-Amino Rearrangement Reaction of <i>N</i>‑Tosylsalicylimines to α,β-Unsaturated Aldehydes by Diarylprolinol Silyl Ethers

An organocatalytic asymmetric enantioselective domino oxa-Michael–Mannich-[1,3]-amino rearrangement reaction of N-tosylsalicylimines with a wide range of α,β-unsaturated aldehydes utilizing diarylprolinol silyl ether catalysis is described. The catalytic reactions proceed with excellent enantioselectivity (up to 99% ee) to produce the corresponding chair N-tosylimines-chromenes with a yield of up to 99%, tolerating a range of functional groups. This methodology offers a new method with great potential to further extend the synthetic power and versatility of chiral aminocatalysis.