Synthesis 2020; 52(14): 2031-2037
DOI: 10.1055/s-0039-1690896
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© Georg Thieme Verlag Stuttgart · New York

Zeolites Catalyze the Nazarov Reaction and the tert-Butylation of Alcohols by Stabilization of Carboxonium Intermediates

María Tejeda-Serrano
,
Sergio Sanz-Navarro
,
Finn Blake
,
Instituto de Tecnología Química, Universidad Politècnica de València, Consejo Superior de Investigaciones Científicas (ITQ, UPV-CSIC), Avda. de los Naranjos s/n, 46022 Valencia, Spain   Email: anleyva@itq.upv.es
› Author Affiliations
This work was supported by the MINECO (Spain) (Projects CTQ 2017-86735-P, RTC-2017-6331-5, and Severo Ochoa program SEV-2016-0683)
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Publication History

Received: 31 January 2020

Accepted after revision: 26 March 2020

Publication Date:
20 April 2020 (online)


Abstract

Zeolites are the most used catalysts worldwide in petrochemistry processes, with particular ability to stabilize carbocations. However, the use of zeolites in organic synthesis is still scarce. We show here that representative carboxonium-mediated organic reactions, such as the Nazarov cyclization and the tert-butylation of alcohols with tert-butyl acetate, typically performed with very strong acid catalysts in solution such as triflic acid, can be catalyzed by simple zeolites with high yield and selectivity. The aluminosilicate framework stabilizes the intermediate carboxonium species and overrides the need for superacid protons in solution.

Supporting Information