Gold‐Catalyzed Cyclizations and [3+2]‐Annulation Cascades between 1,5‐Diyn‐3‐ols and Nitrones to Construct Carbazole Frameworks
Sudhakar Dattatray Tanpure, Manoj Dilip Dhole, Rai‐Shung Liu
Abstract
Abstract Gold‐catalyzed cascade reactions between 1,5‐diyn‐3‐ols and nitrones to deliver carbazole derivatives are described. Such cascade reactions are applicable to facile synthesis of polyaromatic compounds containing carbazole subunits. Notably, the reaction mechanism involves unexpected oxoarylations, rather than oxidative Mannich reactions as known for but‐1‐yn‐4‐ols. Our control experiments indicate that the presence of a second alkyne as in 1,5‐diyn‐3‐ols enables such oxoarylations due to a weak bonding between gold and this alkyne, rending the tethered alcohol less conformationally flexible.
Topics & Concepts
ChemistryCarbazoleAlkyneCatalysisAnnulationCascadeCombinatorial chemistryCascade reactionMedicinal chemistryOrganic chemistryChromatographyCatalytic Alkyne ReactionsCatalytic C–H Functionalization MethodsOxidative Organic Chemistry Reactions