Groebke-Blackburn-Bienaymé Multicomponent Reaction Catalysed by Reusable Brϕnsted-Acidic Ionic Liquids

Abstract

In the present work, the use of Brϕnsted acidic ionic liquids (BAIL) as catalysts for Groebke-Blackburn-Bienaymé (GBB) multicomponent reactions was systematically investigated. A series of four 1-(butyl-4-sulfonic)-3-methylimidazolium salts bearing different anions was easily prepared and screened as acidic catalysts for this transformation. The best reaction conditions were stablished as 20 mol % of catalyst [(SO3H)4C4C1Im][OTf] in refluxing EtOH or MeOH under conventional heating and in sealed tube at 150 °C for 1–4 hours under microwave heating, affording a series of imidazo-fused heterocycles in moderate to excellent yields (42–93 %). The homogeneous BAIL catalyst could be recycled and reused in four consecutive reaction cycles, despite of a laborious recovery procedure employed. This approach represents the first example of a task-specific reusable homogeneous Brϕnsted acidic catalyst in GBB reactions and opens new opportunities for the exploration of acidic ionic liquid phases as catalysts for this fascinating multicomponent reaction.

Citation

Anjos, N. S., Chapina, A. I., Santos, A. R., Licence, P., & Longo Junior, L. S. (2022). Groebke-Blackburn-Bienaymé Multicomponent Reaction Catalysed by Reusable Brϕnsted-Acidic Ionic Liquids. European Journal of Organic Chemistry, 2022(40), Article e202200615. https://doi.org/10.1002/ejoc.202200615

• Journal Article Type: Article
• Acceptance Date: Sep 1, 2022
• Online Publication Date: Sep 4, 2022
• Publication Date: Oct 26, 2022
• Deposit Date: Sep 26, 2022
• Publicly Available Date: Sep 5, 2023
• Journal: European Journal of Organic Chemistry
• Print ISSN: 1434-193X
• Electronic ISSN: 1099-0690
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 2022
• Issue: 40
• Article Number: e202200615
• DOI: https://doi.org/10.1002/ejoc.202200615
• Keywords: Organic Chemistry; Physical and Theoretical Chemistry
• Public URL: https://nottingham-repository.worktribe.com/output/11461897
• Publisher URL: https://chemistry-europe.onlinelibrary.wiley.com/doi/10.1002/ejoc.202200615
• Additional Information: Received: 2022-05-28; Accepted: 2022-09-01; Published: 2022-09-04