A sequential multicomponent reaction between ketoesters, isothiocyanates and 1,2-diaza-1,3-dienes to create 2,5-dihydrothiophenes that can be converted into thiophenes.

Zn(II)-catalyzed divergent synthesis of functionalized polycyclic indolines through formal [3+2] and [4+2] cycloadditions of indoles with 1,2-diaza-1,3-dienes (DDs) is reported. Nature and type of substituents of substrates are found to act as chemical switch to trigger two distinct reaction pathways and to obtain two different types of products upon the influence of the same catalyst. The mechanism of both [4+2] and [3+2] cycloadditions was investigated and fully rationalized by density functional theory (DFT) calculations.

Dihydroberberine (DHBER), the partially reduced form of the alkaloid berberine (BER), is known to exhibit important biological activities. Despite this fact, there have been only few studies that concern the biological properties of functionalized DHBER. Attracted by the potentiality of this latter compound, we have realized the preparation of new arylhydrazono-functionalized DHBERs, starting from BER and some α-bromohydrazones. On the other hand, also the fully reduced form of BER, namely tetrahydroberberine (THBER), and its derivatives have proven to present different biological activities. Therefore, the obtained arylhydrazono-functionalized DHBERs were reduced to the corresponding arylhydrazono-THBERs. The antiproliferative activity of both arylhydrazono-DHBERs and -THBERs has been evaluated on NCI-H1975 lung cancer cells.

An unprecedented synthesis of polysubstituted indole-fused pyridazines (azacarbolines) from α-indolylhydrazones under oxidative conditions using a combination of iodylbenzene (PhIO₂) and trifluoroacetic acid (TFA) has been developed. This transformation is conducted without the need for transition metals, harsh conditions, or an inert atmosphere.

The direct synthesis of pyrrolo[2,3- b ]indoles is developed using a Cu/Fe cocatalyzed intramolecular cycloamination of α-indolylhydrazones. This transformation proceeds cleanly and selectively at 50 °C in air, with water as the only reaction medium.