Proline-derived dichlorophenyl-substituted urea as catalyst for “on-water” asymmetric addition reactions of oxoindoles to nitroolefins

The dichlorophenyl-substituted chiral urea derived from proline was designed and synthesized as a bifunctional organocatalyst for the “on-water” asymmetric Michael addition of less-hydrophobic oxoindoles to nitroolefins. Employing only 1 mol% of this bifunctional organocatalyst demonstrated exceptional catalytic efficiency (>90 % yield in most cases) and stereoselectivity in reactions involving various 3-substituted oxoindoles (up to > 99 % de and 96 % ee) and nitroolefins (up to > 99 % de and 98 % ee).