Cinchona alkaloid/TMAF combination: Enantioselective trifluoromethylation of aryl aldehydes

The catalytic enantioselective trifluoromethylation reaction of aromatic aldehydes using the Ruppert–Prakash reagent (Me3SiCF3) has been disclosed, with an operationally simple procedure, based on the combination of sterically demanding cinchona alkaloid-derived phase-transfer catalyst 3b with tetramethylammonium fluoride (TMAF). Our methodology provides medicinally important α-trifluoromethyl alcohols with high chemical yields and moderate to good enantioselectivities (50–70% ee).