N-Heterocyclic Carbene-Catalyzed [3 + 3] Annulation of 5-Aminopyrazoles with Enals: Enantioselective Synthesis of Pyrazolo[3,4-<i>b</i>]pyridones
Jiahan Li, Xiaoyong Duan, Xiaojie Ren, Yanting Li, Jing Qi
Abstract
An enantioselective construction of pyrazolo[3,4- b ]pyridones was achieved via N-heterocyclic carbene-catalyzed [3 + 3] annulation of enals with 5-aminopyrazoles. This protocol not only offers a highly efficient synthetic approach for the preparation of various substituted pyrazolo[3,4- b ]pyridones but also provides an effective method for the rapid synthesis of enantiopure spirooxindone derivatives.
Topics & Concepts
Enantioselective synthesisAnnulationEnantiopure drugCarbeneCatalysisChemistryCombinatorial chemistryStereochemistryOrganic chemistryN-Heterocyclic Carbenes in Organic and Inorganic ChemistryCatalytic C–H Functionalization MethodsSynthetic Organic Chemistry Methods