Cinchona Derivatives as Bifunctional H‐bonding Organocatalysts in Asymmetric Vinylogous Conjugate Addition Reactions
Harshit Joshi, Vinod K. Singh
Abstract
Abstract Asymmetric vinylogous conjugate addition reactions constitute an essential class of enantioselective C−C bond‐forming transformations characterized by remote functionalization of substrates and the construction of distal stereocenters. After the renaissance of organocatalysis in 2000, vinylogous addition methodologies have seen new horizons of development. Cinchona alkaloids and some of their derivatives have appeared as efficient chiral catalysts in several organic transformations. Their non‐toxicity, low cost, availability in pseudo‐enantiomeric forms, and “open flask” reaction procedures have been the main reasons behind their success in asymmetric synthesis. These organocatalysts have also shown remarkable applications in vinylogous chemistry. This mini‐review covers the developments of asymmetric vinylogous conjugate addition (VCA) reactions under bifunctional cinchona alkaloids/derivatives catalysis.