Diastereoselective multicomponent phosphoramidate-aldehyde-dienophile (PAD) process for the synthesis of polysubstituted cyclohex-2-enyl-amine derivatives

Abstract

The reaction of diethyl phosphoramidate, conjugated aldehydes and maleimides takes place in a multicomponent sequence named phosphoramidate-aldehyde-dienophile (PAD). The reaction affords a series of N-substituted phosphoramidates in good yields with α,β-unsaturated aldehydes bearing hydrogens at the γ-position. The reaction is diastereoselective and the effect of chiral information in the maleimide is evaluated. A mechanism is also postulated and the feasible hydrolysis of the phosphoramidate functional group is achieved although the final allylic amine is difficult to isolate.