Regioselective α-addition of vinylogous α-ketoester enolate in organocatalytic asymmetric Michael reactions: enantioselective synthesis of Rauhut–Currier type products

Abstract

Catalytic asymmetric α-regioselective Michael additions of vinylogous α-ketoester enolate are described herein.

Progress in catalytic asymmetric α-functionalization of vinylogous nucleophilic species

“…In 2022, Guo's group extended the scope of α-functionalization of unsaturated ketones to the deconjugated unsaturated α-keto ester (Scheme 48). 62 The reactions between γ,δ-unsaturated α-keto ester 194 and various nitroolefins 25 proceeded smoothly under the catalysis of cyclohexanediamine-derived chiral bifunctional organocatalyst C28 , leading to the formation of the Rauhut–Currier type products 195 via double bond isomerization in good isolated yields (69–88%) with excellent regio- and enantioselectivities (94–>99% ee). The authors also pointed out that the developed protocol was not compatible with nitroolefins bearing two substrates at the β-position, β,γ-unsaturated α-ketoester, and unsaturated α-keto ester with a stable dienolate.…”