Cinchona alkaloid/TMAF combination: Enantioselective trifluoromethylation of aryl aldehydes
摘要:
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 alpha-trifluoromethyl alcohols with high chemical yields and moderate to good enantioselectivities (50-70% ee). (c) 2013 Elsevier B.V. All rights reserved.