225920-05-8

White solid

Aprepitant intermediate.

General procedure: under argon protection, the ruthenium complex Ru(OTf)[(S,S)-iso-BuSO2dpen] (p-cymene) (1.4 mg, 0.002 mmol), potassium formate (1.0 g, 12 mmol), and 3,5-bis(trifluoromethyl)acetophenone (2.56 g, 10 mmol, substrate to catalyst ratio 5000:1) were added to a 20 mL glass Schlenk reaction tube. Subsequently, methanol (6 mL) was added and the reaction was stirred at 50 °C for 24 hours. Upon completion of the reaction, (S)-1-[3,5-bis(trifluoromethyl)phenyl]ethanol was obtained in 100% yield with an enantiomeric excess (ee) value of 87.7%.

[1] Patent: US2011/282077, 2011, A1. Location in patent: Page/Page column 8
[2] Angewandte Chemie - International Edition, 2011, vol. 50, # 32, p. 7329 - 7332
[3] Tetrahedron Asymmetry, 2006, vol. 17, # 4, p. 554 - 559
[4] Patent: CN108059579, 2018, A. Location in patent: Paragraph 0057-0061
[5] Tetrahedron, 2004, vol. 60, # 3, p. 789 - 797