Highly enantioselective synthesis of long chain alkyl trifluoromethyl carbinols and beta-thiotrifluoromethyl carbinols through lipases

Among a variety of lipases tested, Candida antarctica lipase has been found to promote the enantioselective acylation of long chain alkyl trifluoromethyl carbinols 1a-4a and beta-thiotrifluoromethyl carbinols 5a-7a, producing both R and S enantiomeric alcohols in good to excellent chemical yield and enantioselectivity. In all cases the lipase preferentially acylates the S enantiomer, irrespective the presence or not of a sulfur atom in beta position to the hydroxyl group, When the reaction was carried out on the non-fluorinated substrates 1c-2c, the process occurred much faster and with higher e.e. of the less reacting enantiomer than when conducted on the fluorinated substrates. Copyright (C) 1996 Elsevier Science Ltd