Stereoselective synthesis of functionalized chiral 2- nitrocyclohexanecarboxylic esters via catalytic dienamine addition to β-substituted β-nitroacrylates

A metal-free stereoselective catalytic addition of in situ generated dienamine to β-nitroacrylates has been developed. Starting from simple α,β unsaturated ketones, highly functionalized chiral β-nitrocyclohexanecarboxylic esters were obtained in a single step, in good yields and up to 98% ee. By an unprecedented mechanistic pathway, starting from the synthetically readily available E-nitroacrylate, the present methodology allowed us to obtain as major product the isomer bearing a cis relative disposition between the nitro and the ester groups, which is not accessible via a classical Diels-Alder reaction.