Cyclization of 1-aryl-4,4,4-trichlorobut-2-en-1-ones into 3-trichloromethylindan-1-ones in triflic acid.

ABSTRACT: Trichloromethyl-substituted enones (1-aryl-4,4,4-trichlorobut-2-en-1-ones, ArCOCH=CHCCl₃, CCl₃-enones) undergo intramolecular transformation into 3-trichloromethylindan-1-ones (CCl₃-indanones) in Brønsted superacid CF₃SO₃H (triflic acid, TfOH) at 80 °C within 2-10 h in yields up to 92%. Protonation of the carbonyl oxygen of the starting CCl₃-enones by TfOH affords the key reactive intermediates, the O-protonated forms ArC(=OH⁺)CH=CHCCl₃, which are then cyclized into the target CCl₃-indanones. These cations have been studied experimentally by means of NMR spectroscopy in TfOH and theoretically by DFT calculations. Under the same superacidic conditions in TfOH, CCl₃-hydroxy ketones (

SUBMITTER: Sokolov VA 

PROVIDER: S-EPMC10548255 | biostudies-literature | 2023

REPOSITORIES: biostudies-literature