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.

An efficient Microwave (MW)-assisted synthesis of eight new 6-nitrilmethyl-pyrrolo[3,4-b]pyridin-5-ones via a domino process: aza Diels–Alder/N-acylation/aromatization (dehydration–decarboxylation) from their corresponding 2-aminonitrile-oxazoles and maleic anhydride are described. The use of MW as a heat source and scandium (III) triflate as a catalyst to promote the cycloaddition process was crucial to construct these polyfunctionalized products in very good yields (51–79%), considering both their molecular complexity and that only one domino-type experimental procedure was required for their synthesis. It is worth noting that all products reported herein have not been synthesized nor isolated anywhere. However, they can be of high interest for the synthetic and medicinal chemistry community because pyrrolo[3,4-b]pyridin-5-one is the structural core of various bioactive compounds. In the same context, it can be considered as a privileged aza analogue of the isoindolin-1-one, which in turn is the core of numerous anticancer agents.

2,5-DKPs are heterocyclic peptidomimetics, present in nature with high structural diversity, popular in the design of new bioactive molecules with potential application in medicinal chemistry, exhibiting anticancer and antimicrobial properties, among others. Therefore, in the present work, we report the one-pot synthesis of 2,5-DKPs and their links to another heterocycle 1,4-disubstituted 1,2,3-triazole under mild reaction conditions by one-pot process via the sequence IMCR/postransformation/CuAAC with several advantages over previously reported conventional methods.

6-Triazolylmethyl-pyrrolo[3,4-b]pyridin-5-one tris-heterocycles were synthesized in 43–57% overall yields. The two-stage synthesis involved a cascade process (Ugi-3CR/aza Diels-Alder/N-acylation/aromatization) followed by a copper-assisted alkyne-azide [3+2] cycloaddition (CuAAC). This efficient and convergent strategy proceeded via complex terminal alkynes functionalized with a