Triflic Acid

Gigant, Nicolas

doi:10.1055/s-0032-1318074

Cited by 2 publications

(1 citation statement)

References 7 publications

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“…Superelectrophilic activation of organic compounds under the action of strong Brønsted and Lewis acids is an effective method for the synthesis of various carbocycles and heterocycles, and polyfunctional compounds (see books [1,2] and reviews [3][4][5][6][7][8][9][10]). Protonation (or coordination) of basic centers (carbons of unsaturated bonds and heteroatoms) of organic mol-ecules in Brønsted (or Lewis) acids gives rise to not only monocations, but also to highly reactive dicationic (and even higher charged) species.…”

Section: Introductionmentioning

confidence: 99%

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

Sokolov,

Golushko,

Boyarskaya

et al. 2023

Beilstein J. Org. Chem.

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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 (1-aryl-4,4,4-trichloro-3-hydroxybutan-1-ones; ArCOCH2CH(OH)CCl3) undergo dehydration to the corresponding CCl3-enones, which are further cyclized into CCl3-indanones. The yields of CCl3-indanones starting from CCl3-hydroxy ketones are up to 86% in TfOH at 80 °C within 3–18 h.

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