Reduction of 2,2,2-trifluoro-1-arylethanones with alkyl phosphines

In the presence of alkyl phosphines, reduction of 2,2,2-trifluoro-1-arylethanones proceeded smoothly to give the corresponding reduction products in moderate to high yields at room temperature. The possible mechanism was discussed on the basis of deuterium labeling and control experiments, indicating that one hydrogen transfer took place from alkyl phosphine to the carbonyl group activated by a strongly electron-withdrawing trifluoromethyl group.