Ring Opening and Closure Reactions of beta-Propiolactone in the Superacids HF/MF5 (M=Sb, As)

Beck, Stefanie; Jessen, Christoph and Kornath, Andreas J. (2021): Ring Opening and Closure Reactions of beta-Propiolactone in the Superacids HF/MF5 (M=Sb, As). In: European Journal of Organic Chemistry, Vol. 2021, No. 48: pp. 6628-6635

Abstract

Transformations of beta-propiolactone in the binary superacidic systems HF/MF5 (M = Sb, As) were investigated at different temperatures. Salts of monoprotonated 3-hydroxypropanoyl fluoride [H2O(CH2)(2)C(O)F][SbF6] (1) and [H2O(CH2)(2)C(O)F][AsF6] (2) were obtained by performing the reactions at temperatures lower than -40 degrees C. In contrast, temperatures higher than -40 degrees C yield the respective salts [C9H15O6][SbF6](3) (3) and [C9H15O6][AsF6](3) (4) containing a cyclic trication. The protonated species of beta-propiolactone was not observed. All salts were characterized by low temperature Raman and IR spectroscopy. In addition, single-crystal X-ray analyses were performed for (1) and (3). For both cations the existence of a cationic acyl species as a reactive intermediate in the form of [HO(CH2)(2)CO][MF6] is assumed. The formation of the acyl cation, based on protonated beta-propiolactone, was investigated by quantum chemical calculations on the MP2/aug-cc-pVTZ level of theory.

• Item Type: Journal article
• Faculties: Chemistry and Pharmacy
• Subjects: 500 Science > 540 Chemistry
• ISSN: 1434-193X
• Language: English