An Enantioselective Three‐Component Sulfa‐Michael/Aldol Cascade Reaction and its Application to the Synthesis of Thioaryl Substituted (−)‐Bestatin Derivatives

An efficient catalytic asymmetric three‐component sulfa‐Michael/aldol cascade reaction has been developed using a chiral multi‐functional catalyst. This reaction provided facile access to γ‐sulfur‐β‐nitro‐α‐hydroxy esters bearing three consecutive linear stereocenters in high yields (up to 97%) with excellent diastereo‐ (up to >97:3 dr) and enantioselectivities (>99% ee). These compounds were readily converted into 2‐nitroallylic alcohols and potentially bioactive γ‐sulfur‐β‐amino‐α‐hydroxy esters, which could be further used for the synthesis of Bestatin derivatives.