Synthesis of binaphthyl sulfonimides and their application in the enantioselective Michael addition of ketones to nitroalkenes

Novel types of L-proline-based binaphthyl sulfonimides and sulfonamides were found to be efficient organocatalysts for the asymmetric Michael addition of ketones to nitroalkenes to provide optically active γ-nitroketone derivatives of synthetic and biological importance. After the fine optimization of solvents, temperature, and additive, good to excellent enantioselectivities and diastereoselectivities (71-96%ee, up to >99:1 dr) can be achieved.