A novel strategy via the triple process (multicomponent reactions (MCR)-domino)/tandem was developed for the synthesis of restricted and constrained bis-1,2,3-triazole-linked pyrrolo[3,4-b]pyridine peptidomimetics dimers in overall yields of 20–55%. This strategy allows the construction of six heterocycles in two stages of the reaction.

Eight novel 2-aminonitrile oxazoles were synthesized efficiently and quickly via the Ugi reaction in its three-component version in moderate to good yields (55-82%) at room temperature or in good to excellent yields (70-96%) using ultrasound irradiation (USI) as heat source. It is noteworthy that not only the yields were improved by using USI, also the reaction times decreased considerably, from 6-10 hours (at r.t.) to 1-2 hours (USI), depending on the substituents. The final products are highly functionalized molecules because they contain an amino group, a nitrile group, an oxazole group and a very reactive biaryl-benzylic position. In this context, they can be used for further condensations, cyclizations and/or functionalizations toward a variety of compounds with potential applications in several fields of knowledge like optics, material science and medicinal chemistry. All products were fully characterized by spectroscopic techniques (H and C-NMR, IR and HRMS), even by mp and Rf.

Six novel imidazo[1,2-a]pyridines were synthesized by Groebke–Blackburn–Bienaymé reactions (GBBRs) under eco-friendly conditions (10 mol% ammonium chloride catalyst in EtOH at room temperature) with moderate to good yields (76–44%) using 2-isocyano-1-morpholino-3-phenylpropan-1-one. This is the first successful use of this type of α-isocyanoacetamide in a GBBR, as these reactive isonitriles readily undergo ring-chain tautomerization, as reported in other IMCRs (isonitrile-based multicomponent reactions). The product structures contain a peptidomimetic imidazo[1,2-a]pyridine scaffold linked to an α-aminomorpholide and are of interest to medicinal chemists.

A series of three 2,5-Diketopiperazine (DKPs) were synthesized via one-pot process through the post- isocyanide-based multicomponent reactions (IMCR)-transformation strategy. This strategy emphasizes the role of orthogonal bifunctional reagents in the IMCR process to increase their synthetic potential, allowing us accessing a synthetic platform from which it is possible to obtain privileged heterocyclic peptidomimetics via lactamization reaction.