Highly enantio- and diastereoselective synthesis of α- trifluoromethyldihydropyrans using a novel bifunctional piperazine-thiourea catalyst
The first enantioselective Michael addition of α-cyanoketones to α,β-unsaturated trifluoromethyl ketones using a novel piperazine-thiourea catalyst was described. The resulting α- trifluoromethyldihydropyrans were obtained in high yields and with up to 95