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In Situ Anodically Oxidized BMIm-BF₄: A Safe and Recyclable BF₃ Source.

ABSTRACT: The anodic oxidation of 1-butyl-3-methylimidazolium tetrafluoroborate (BMIm-BF₄) efficiently generates BF₃ from BF₄^-. This Lewis acid, strongly bound to the ionic liquids, can be efficiently used in classical BF₃-catalyzed reactions. We demonstrated the BF₃/BMIm-BF₄ reactivity in four reactions, namely, a domino Friedel-Crafts/lactonization of phenols, the Povarov reaction, the Friedel-Crafts benzylation of anisole, and the multicomponent synthesis of tetrahydro-11H-benzo[a]xanthen-11-ones. In comparison with literature data using BF₃-Et₂O in organic solvents, in all the presented cases, analogous or improved results were obtained. Moreover, the noteworthy advantages of the developed method are the in situ generation of BF₃ (no storing necessity) in the required amount, using only the electron as redox reagent, and the recycling of BMIm-BF₄ for multiple subsequent runs.

SUBMITTER: Bortolami M

PROVIDER: S-EPMC8609525 | biostudies-literature | 2021 Nov

REPOSITORIES: biostudies-literature

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In Situ Anodically Oxidized BMIm-BF4: A Safe and Recyclable BF3 Source.

Bortolami Martina M Mattiello Leonardo L Scarano Vincenzo V Vetica Fabrizio F Feroci Marta M

The Journal of organic chemistry 20210702 22

The anodic oxidation of 1-butyl-3-methylimidazolium tetrafluoroborate (BMIm-BF4) efficiently generates BF3 from BF4-. This Lewis acid, strongly bound to the ionic liquids, can be efficiently used in classical BF3-catalyzed reactions. We demonstrated the BF3/BMIm-BF4 reactivity in four reactions, namely, a domino Friedel-Crafts/lactonization of phenols, the Povarov reaction, the Friedel-Crafts benzylation of anisole, and ...[more]

PMID: 34213898

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