A general synthesis of 1,3-dicarbonylic compounds using multicomponent reactions of isocyanides is described. The process involves a Passerini three-component condensation of glyoxal derivatives, isocyanides and acetic acid, followed by metal mediated reductive or solvolytic removal of the acid component. Noteworthy, reductive deacetoxylation of Passerini glyoxylamide adducts was successfully achieved using photochemically activated SmI(2). This procedure constitutes a novel convenient method for the direct synthesis of malonic retro-peptidic subunits.

2-Aminobenzothiazoles are readily synthesised from anilines, sulfur monochloride and isocyanides. The key step consists of an iodine-catalysed insertion of isocyanides into the S-S bond of hydrolysed Herz salts, with concomitant extrusion of sulfur monoxide.

A novel synthesis of hydroxyglycine retropeptidic derivatives was achieved through a Passerini 3-component reaction of glyoxyl amides or esters, followed by an unprecedented environmentally benign zinc catalysed solvolysis.

A novel synthesis of polyfunctionalised pyridones, structurally related to cardiotonic agent milrinone is described. The procedure consists of an Ugi four-component reaction of 3-formylchromones, followed by a base-promoted ring-opening/ring-closing process. Variation of three of the four components in the Ugi reaction allows access to the final products with a combinatorial distribution of substituents.

Pyridine derivatives R 0380 Multicomponent Synthesis of Highly Substituted 2-Pyridones. -An efficient two-step synthesis of highly functionalized 2-pyridones (VI) involves an Ugi four-component condensation of chromones (I) with a diversity of arylamines (II), isonitriles (III) and cyanoacetic acid (IV) as key step. The chromone moiety in compound (V) is cleaved under basic conditions to close the pyridone ring (VI). -(NEO, A. G.; CARRILLO, R. M.; BARRIGA, S.; MOMAN, E.; MARCACCINI, S.; MARCOS*, C.