261. Electrogenerated BF3 From Tetrafluoroborate-Based Ionic Liquids: Theoretical And Experimental Studies Towards Selective Styrene Oxide Isomerization

Marta Feroci, Martina Bortolami, Rita Petrucci, Giuseppe Zollo, Fabrizio Vetica and Fernando Jr. Piamonte Magboo; Journal of The Electrochemical Society; (2021); DOI: 10.1149/1945-7111/ac39e2

The anodic oxidation of tetrafluoroborate anion yields the Lewis acid BF3. If this reaction is carried out in an imidazolium ionic liquid, a quite stable system containing BF3 is obtained, whose reactivity is similar to the one of BF3·Et2O, but less harmful. The two reagents' stabilities were compared by computational analysis, strongly suggesting a higher stability for BF3/BMIm-BF4 system. The effect of substituents on the imidazolium ring and of the electrochemical configuration on BF3 reactivity were studied in a model reaction, styrene oxide isomerization. The experimental conditions were defined for the selective formation of phenylacetaldehyde or of 2-benzyl-4-phenyl-1,3-dioxolane. Moreover, the formation of N-heterocyclic carbene-BF3 adduct was confirmed when carrying out the electrolysis in an undivided cell. Electrogenerated BF3/BMIm-BF4 system demonstrated to be a valid alternative to commercial BF3·Et2O.