Passerini reaction--amine deprotection--acyl migration (PADAM): A convenient strategy for the solid-phase preparation of peptidomimetic compounds.

beta-Acylamino-alpha-hydroxyamides and beta-acylamino-alpha-oxoamides, compounds known to be potent protease inhibitors, can be conveniently prepared with a highly convergent strategy involving a Passerini multicomponent reaction between a N-protected alpha-aminoaldehyde, a carboxylic acid and an isocyanide. After N-deprotection and concomitant acyl migration the desired beta-acylamino-alpha-hydroxyamide moiety is obtained and can be further elaborated, for example via oxidation of the secondary alcohol group. In this paper we report the studies that have been carried out in order to transfer this synthetic methodology onto polystyrene resin, using a photocleavable linker and a N-Boc protecting strategy.