N‐Heterocyclic carbene‐catalyzed Atroposelective Annulation for Access to Pyrrolo[3,4‐b]pyridines Derivatives with C−N Axial Chirality

Abstract

An N‐heterocyclic carbene (NHC) catalyzed atroposelective [3+3] annulation of enals with α‐aminomaleimides is developed. In this strategy, a series of atropisomeric pyrrolo[3,4‐b]pyridine bearing various substituents and substitution patterns are generated in good yields with excellent enantioselectivities.

Atroposelective Access to Dihydropyridinones with C–N Axial and Point Chirality via NHC-Catalyzed [3 + 3] Annulation

“…In 2018, the Wang group reported an NHC-catalyzed kinetic resolution of anilides to afford various C–N axially chiral products . Recently, the [3 + 3] atroposelective annulation of enals with α-aminomaleimide for the synthesis of C–N atropisomers was reported separately by Hui and our group . Meanwhile, the kinetic resolution of aminomaleimide via NHC-catalyzed selective [3 + 3] annulation was reported by Biju and co-workers .…”

N-Heterocyclic Carbene-Catalyzed [3 + 3] Annulation of 5-Aminopyrazoles with Enals: Enantioselective Synthesis of Pyrazolo[3,4-b]pyridones

“…N-Heterocyclic carbene (NHC) catalysis is a famous organocatalysis that has received tremendous research interest in the past few decades . Among different activation modes promoted by NHC, α,β -unsaturated acylazolium was intensively investigated and employed as a key intermediate in many annulation strategies to construct various enantiopure structurally complex molecules. − , On the other hand, 5-aminopyrazole derivatives are popular binucleophiles and can be widely used as starting materials for the construction of functional compounds . Our group is interested in developing new strategies promoted by NHC to synthesize biologically important and structurally complex molecules.…”