Gold-Catalyzed "Back-to-Front" Synthesis of 4-Silyloxyindoles
Miguel A Muñoz-Torres1, Samuel Suárez-Pantiga1, Roberto Sanz1
1Área de Química Orgánica, Departamento de Química, Facultad de Ciencias, Universidad de Burgos, Pza. Misael Bañuelos s/n, 09001 Burgos, Spain.
Abstract:
A series of pyrrol-yn-glycol derivatives were easily prepared from simple pyrroles through a three-step sequence involving hydroxyalkylation-alkynylation-O-silylation. Their reaction with IPrAuNTf2 triggers a C2-pyrrole attack onto the activated alkyne and subsequent highly selective 1,2-migration of the oxyalkyl group in the intermediate spirocycle. This approach enables the efficient synthesis of a wide selection of regioselectively functionalized 4-hydroxyindoles, which represent important yet challenging indole scaffolds, in high yields.
More Related Videos
Related Concept Videos
[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction
Preparation and Reactions of Sulfides
Oxidation of Alkenes: Syn Dihydroxylation with Osmium Tetraoxide
Cyclohexenones via Michael Addition and Aldol Condensation: The Robinson Annulation
Preparation of Diols and Pinacol Rearrangement
The reaction begins with transferring a proton from the acid catalyst to one of the hydroxyl groups, producing an oxonium ion.
Synthesis of α-Substituted Carbonyl Compounds: The Stork Enamine Reaction


