Indium(III)-Catalyzed Synthesis of Benzo[b]furans by Intramolecular Hydroalkoxylation of ortho-Alkynylphenols: Scope and Mechanistic Insights

Alonso-Marañón, Lorena; Martínez, M. Montserrat; Sarandeses, Luis A.; Gómez Bengoa, Enrique; Pérez Sestelo, José

Use this link to cite:

http://hdl.handle.net/2183/35379

Indium(III)-Catalyzed Synthesis of Benzo[b]furans by Intramolecular Hydroalkoxylation of ortho-Alkynylphenols: Scope and Mechanistic Insights

Identifiers

URI: http://hdl.handle.net/2183/35379

DOI: 10.1021/acs.joc.8b00829

Publication date

2018-06-12

Authors

Alonso-Marañón, Lorena

Martínez, M. Montserrat

Sarandeses, Luis A.

Gómez Bengoa, Enrique

Pérez Sestelo, José

Bibliographic citation

Alonso-Marañón, L., Martínez, M. M., Sarandeses, L. A., Gómez-Bengoa, E., and Pérez Sestelo, J. (2018). Indium(III)-Catalyzed Synthesis of Benzo[b]furans by Intramolecular Hydroalkoxylation of ortho-Alkynylphenols: Scope and Mechanistic Insights. The Journal of Organic Chemistry, 83(15), 7970-7980. https://doi.org/10.1021/acs.joc.8b00829

Abstract

[Abstract] Indium(III) halides catalyze the hydroalkoxylation reaction of ortho-alkynylphenols to afford benzo[b]furans in good yields. The reaction proceeds with 5-endo-dig regioselectivity with a variety of phenols functionalized at the arene and alkyne moieties in high yields using InI3 (5 mol %) in DCE. Experimental and computational studies support a mechanism based on the indium(III) π-Lewis acid activation of the alkyne followed by nucleophilic addition of the phenol and final protodemetalation to afford the corresponding benzo[b]furan. DFT calculations suggest that dimer In2I6 is the catalytic species through a novel double coordination with the alkyne and the hydroxyl group.