Affiliation:
1. Área de Química Orgánica Departamento de Química Facultad de Ciencias Universidad de Burgos Pza. Misael Bañuelos s/n 09001- Burgos Spain
2. Universidad de Alcalá (IRYCIS). Departamento de Química Orgánica y Química Inorgánica Instituto de Investigación Química “Andrés M. del Río” (IQAR) 28805-Alcalá de Henares Madrid Spain
Abstract
Abstractα‐Indol‐3‐yl α,β‐unsaturated carbonyl compounds are synthesized from 3‐propargyl indoles, obtained by direct propargylation of indoles, via a gold‐catalyzed tandem oxidation‐1,2‐indole migration reaction in the presence of pyridine N‐oxides. Fine‐tuning of the catalyst and oxidant enables the reaction of 3‐propargyl indoles bearing different substituents. The order of oxidation and indole migration is determined by the terminal or internal nature of the alkyne moiety. In addition, the process can be coupled with additional reactions, allowing an increase in molecular complexity or the design of more elaborated tandem reactions. In this sense, indole derivatives bearing an alkenyl substituent at the alkyne position evolve through a gold‐catalyzed tandem oxidation‐1,2‐indole migration‐Nazarov cyclization producing α‐indolyl cyclopentenones.