Enantioselective Michael additions of aromatic ketones to nitroalkenes catalyzed by isosteviol-derived primary amine-thiourea in aqueous medium

The bifunctional primary amine-thiourea catalysts 1a/b, derived from isosteviol and chiral cyclohexanediamine, were employed to facilitate the asymmetric Michael addition of acetophenone to nitrostyrenes, encompassing a total of 17 substrates. Remarkably, in the presence of water, the reaction proceeded smoothly at room temperature, yielding the corresponding conjugate addition products with high efficiency (up to 98% yield) and exceptional enantioselectivity (up to 96% ee). Furthermore, possible catalytic models were proposed through theoretical simulations.