Mg/BOX complexes as efficient catalysts for the enantioselective Michael addition of malonates to -trifluoromethyl-,-unsaturated ketones and their N-tosyl imines

Magnesium (II)-BOX complexes catalyze the enantioselective Michael addition of malonates to beta-trifluoromethyl enones and their N-sulfonyl imines to give ketones or (E)-enamines bearing a trifluoromethylated stereogenic center, respectively, with good yields and high enantiomeric excesses. Magnesium complexes proved to be more active and stereoselective than zinc and copper analogues in these reactions. (C) 2020 Elsevier Ltd. All rights reserved.