Dearomatizing [2+2+1] Spiroannulation of Indoles with Alkynes
Xiaoqing Han, Jingyuan Liu, Jin‐Bo Lu, Ren‐Xiao Liang, Yi‐Xia Jia
Abstract
A palladium-catalyzed dearomatizing [2+2+1] spiroannulation of indoles with two molecular internal alkynes is developed in the presence of Cu(OAc)2/O2 as the oxidant, in which a domino sequence including C–H activation of indole followed by consecutive Heck reactions is involved. A range of 3,3′-spiroindolines bearing tetrasubstituted cyclopentadiene moieties and exocyclic C═C bonds at C2 are obtained in moderate to excellent yields.
Topics & Concepts
ChemistryIndole testDominoPalladiumCyclopentadieneSequence (biology)Medicinal chemistryCatalysisBiphenylStereochemistryCombinatorial chemistryOrganic chemistryBiochemistryCatalytic C–H Functionalization MethodsCatalytic Cross-Coupling ReactionsCatalytic Alkyne Reactions