TY - JOUR

T1 - Cyclization of 1-aryl-4,4,4-trichlorobut-2-en-1-ones into 3-trichloromethylindan-1-ones in triflic acid

AU - Sokolov, Vladislav A

AU - Golushko, Andrei A

AU - Boyarskaya, Irina A

AU - Vasilyev, Aleksander V

N1 - Sokolov V.A., Golushko A.A., Boyarskaya I.A., Vasilyev A.V. Cyclization of 1-aryl-4,4,4-trichlorobut-2-en-1-ones into 3-trichloromethylindan-1-ones in triflic acid. Beilstein Journal of Organic Chemistry. 2023, V. 19, P. 1460-1470.

PY - 2023/9/27

Y1 - 2023/9/27

N2 - Trichloromethyl-substituted enones (1-aryl-4,4,4-trichlorobut-2-en-1-ones, ArCOCH=CHCCl 3, CCl 3-enones) undergo intramolecular transformation into 3-trichloromethylindan-1-ones (CCl 3-indanones) in Brønsted superacid CF 3SO 3H (triflic acid, TfOH) at 80 °C within 2-10 h in yields up to 92%. Protonation of the carbonyl oxygen of the starting CCl 3-enones by TfOH affords the key reactive intermediates, the O-protonated forms ArC(=OH +)CH=CHCCl 3, which are then cyclized into the target CCl 3-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, CCl 3-hydroxy ketones (1-aryl-4,4,4-trichloro-3-hydroxybutan-1-ones; ArCOCH 2CH(OH)CCl 3) undergo dehydration to the corresponding CCl 3-enones, which are further cyclized into CCl 3-indanones. The yields of CCl 3-indanones starting from CCl 3-hydroxy ketones are up to 86% in TfOH at 80 °C within 3-18 h.

AB - Trichloromethyl-substituted enones (1-aryl-4,4,4-trichlorobut-2-en-1-ones, ArCOCH=CHCCl 3, CCl 3-enones) undergo intramolecular transformation into 3-trichloromethylindan-1-ones (CCl 3-indanones) in Brønsted superacid CF 3SO 3H (triflic acid, TfOH) at 80 °C within 2-10 h in yields up to 92%. Protonation of the carbonyl oxygen of the starting CCl 3-enones by TfOH affords the key reactive intermediates, the O-protonated forms ArC(=OH +)CH=CHCCl 3, which are then cyclized into the target CCl 3-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, CCl 3-hydroxy ketones (1-aryl-4,4,4-trichloro-3-hydroxybutan-1-ones; ArCOCH 2CH(OH)CCl 3) undergo dehydration to the corresponding CCl 3-enones, which are further cyclized into CCl 3-indanones. The yields of CCl 3-indanones starting from CCl 3-hydroxy ketones are up to 86% in TfOH at 80 °C within 3-18 h.

KW - еноны, инданоны, циклизация

U2 - 10.3762/bjoc.19.105

DO - 10.3762/bjoc.19.105

M3 - Article

C2 - 37799178

VL - 19

SP - 1460

EP - 1470

JO - Beilstein Journal of Organic Chemistry

JF - Beilstein Journal of Organic Chemistry

SN - 1860-5397

ER -