Palladium-Catalyzed Direct C–H Glycosylation of Free (<i>N</i>-H) Indole and Tryptophan by Norbornene-Mediated Regioselective C–H Activation
Neha Singh Chauhan, Atul Dubey, Pintu Kumar Mandal
Abstract
We describe the palladium-catalyzed direct C–H glycosylation of free N-H indole or tryptophan for the stereoselective synthesis of 2-glycosylindoles and tryptophan-C-glycosides. This reaction relies on the ortho-directing transient mediator norbornene, which underwent regioselective C–H functionalization at the indole or tryptophan ring, providing high chemoselectivity. This method offers a more straightforward, step-economical, and cost-effective route to construct C-glycosides. The gram-scale amenable building blocks can be further functionalized at C3 and N-H, displaying the robustness of present method.
Topics & Concepts
ChemistryIndole testRegioselectivityGlycosylationTryptophanPalladiumCatalysisNorborneneCombinatorial chemistryStereochemistryOrganic chemistryAmino acidBiochemistryMonomerPolymerCatalytic C–H Functionalization MethodsSynthesis and Catalytic ReactionsCyclopropane Reaction Mechanisms