In this paper we report the use of an intramolecular Ugi reaction to synthesize new 4-azacholestanes diversely substituted both at N-4 and C-5. Both the scope and the stereochemical outcome of this approach were studied ...

In this work, we describe how stereochemically complex polycyclic compounds can be generated by applying a synthetic sequence comprising an intramolecular Ugi reaction followed by a Pictet-Spengler cyclization on steroid-derived ...

In this Letter we report that the Ugi reaction/cyclization sequence on a steroidal 17-carboxaldehyde leads to novel steroidal 2,5-diketopiperazines with a noteworthy stereoselectivity. A wide variety in the substitution ...

In this work, a reaction protocol was developed for a new class of pseudo-peptides through multicomponent reactions (MCR) of the Ugi’s four component reaction (U-4CR) type, starting from chalcogenonucleosides. The synthetic ...

The use of arylglyoxal as starting material in Passerini and Ugi reactions affords β-ketoamides. This has allowed to study keto-enol tautomerism in these systems and assess the way in which the presence of acyloxy or ...

Em locais onde os efluentes não recebem o tratamento adequado, antes de retornar aos corpos d’água, ocorrerá um aumento de nutrientes disponíveis no sistema aquático (eutrofização) e consequente aumento na quantidade de ...