Chiral Amine-Thiourea Catalyst for the Asymmetric Michael Addition

Significance

The new bifunctional primary amine-thiourea catalyst 1 is described. This catalyst converts ketones 2 and nitroalkenes 3 into the corresponding nitroalkanes 4 in good to high yields (70-94%) and in excellent enantioselecitivities (91-99%). Nitroalkenes bearing an aliphatic substituent in β-position are also suitable substrates. Even adjacent stereocenters could be established with this method. For example, heptan-3-one and nitrostyrene gave the product with almost perfect regio- and enantioselectivity and good diastereoselectivity (15:1). Ten additional examples are reported.