Stereoselective synthesis of new vicinal diaminoalkyl naphthols by three component Mannich type reaction of alpha,beta-unsaturated aldehydes

The application of the aromatic Mannich reaction to alpha,beta-unsaturated aldehydes, affords a series of new diaminoalkyl naphthols, by a convenient solventless reaction, starting from inexpensive and easily avail-able starting materials. The absolute configurations of the products obtained are attributed on the basis of the coupling constant values of 1H-NMR spectra, joined with the conformational analysis of the molecules by molecular modelling. A mechanistic hypothesis is proposed, which involves an imino–amino intermediate