Facile one-pot synthetic access to libraries of diversely substituted 3-aryl (Alkyl)-coumarins using ionic liquid (IL) or conventional base/solvent, and an IL-mediated approach to novel coumarin-bearing diaryl-ethynes. Issue 20 (14th May 2020)

• Record Type: Journal Article
• Authors: Prabhala, Pavankumar; Savanur, Hemantkumar M.; Sutar, Suraj M.; Malunavar, Shruti S.; Kalkhambkar, Rajesh G.; Laali, Kenneth K.
• Is Part Of: Tetrahedron letters. Volume 61:Issue 20(2020)
• Publication Date: 2020-05-14
• Subjects: 3-aryl(alkyl)coumarins -- Coumarin-bearing diaryl-ethynes -- Salicylaldehydes and aryl(alkyl)-acetic acids -- Carbonyldiimidazole -- Ionic liquids; Chemistry, Organic -- Periodicals; 547.005
• DOI: 10.1016/j.tetlet.2020.151854
• Languages: English
• ISSNs: 0040-4039

Abstract

Graphical abstract: Highlights: Libraries of diversely substituted 3-aryl-coumarins via in-situ formed carbonylimidazole derivatives of Ar(alkyl)-CH2 COOH. IL-mediated synthesis of coumarin-bearing diaryl-ethynes by the Sonogashira reaction. One-pot sequential process. [BMIM][X] as solvent and [PAIM][NTf2 ] as base. Potential for recycling/reuse of the IL solvent. Abstract: The in-situ formed carbonylimidazole derivatives of Ar(alkyl)-CH2 COOH react at r.t. with substituted salicylaldehydes in [BMIM][PF6 ] or [BMIM][BF4 ] as solvent, and [PAIM][NTf2 ] as basic-IL, to produce libraries of 3-aryl(alkyl)coumarins. Whereas these reactions can also be performed with similar efficiency in THF by employing DBU, the IL approach offers easier work-up and recycling of the IL solvent. An IL-mediated approach to the synthesis of novel coumarin-bearing diaryl-ethynes by the Sonogshira reaction is also reported, and the potential for recycling/reuse of the IL solvent is shown.