Chiral C3-spiro-cyclopentaneoxindoles are primarily formed through organocatalysis (CA, NHC, CPA, HB, and PTC) using four types of substrates.
This review summarizes modern stereoselective enolate and homoenolate Michael addition/annulation reactions to nitroalkene-containing benzo-fused heterocycles, enabling efficient access to complex polycyclic heterocycles with biological importances.
The applications of 2-hydroxy-β-nitrostyrenes as efficient bifunctional intermediates for the asymmetric synthesis of chromans, chromenes, coumarins, benzofurans, natural products, and other cyclic and acyclic compounds were reviewed in this paper.
Squaramide-catalyzed asymmetric cyclization of nitroalkenes with 3-benzoylacylamides delivers γ-lactams in 25–90% yield and 71–99% ee with broad compatibility.
A base-catalyzed cascade vinylogous Michael/Michael addition of alkylidene succinimides and oxindole-derived pyrazolones has been developed for the construction of penta-substituted cyclopentanes.