Pyrrolo-[3,2-b]pyrroles represent a class of promising materials for application in organic electronics with interesting optoelectronic properties and great synthesis versatility, but yields obtained from varied synthetic routes are still very low, hindering their effective application for industrial purposes. In this report, we present a method for the synthesis of tetraaryl-1,4-dihydropyrrolo-[3,2-b]pyrrole derivatives by multicomponent reactions employing niobium pentachloride as a catalyst. The optical characterization of the products is also presented. Electronic structure calculations were performed to help the interpretation of the synthesis process, as well as the optical properties of the systems. Excellent yields and low reaction times were obtained, indicating that NbCl 5 is an efficient catalyst for such systems. The products show promising properties for optoelectronic applications that can be adjusted by the choice of benzaldehyde derivatives used in the synthesis.

A virus outbreak challenges the economic, medical, and public health infrastructure worldwide. More than one virus capable of triggering diseases have been identified per year since 1972, which requires the development of new ways of treatment and prevention, however, such processes are not rapid and easy. With the pandemic scenario experienced since early 2020, several drugs with well-known purposes have gained prominence, due to speculation of their use in the treatment against the new coronavirus. Among the main drugs studied, the vast majority contain a heterocyclic structure. In this review, we presented the traditional and efficient synthesis of 15 drugs that have been studied for the COVID-19 treatment, containing in their structure heterocycles like indole, quinoline, pyrimidone, tetrahydrofuran, pyrrolidine, triazole, pyridazine, pyrazole, pyrrolopyrimidine, azetidine, pyrrolotriazine, pyrazine, tetrahydropyran, benzofuran, spiroketal, and thiazole. Furthermore, we have shown the original applications, as well as their structure-activity relationship and what is their situation as a drug candidate against COVID-19. Thus, the objective was to consolidate the main synthetic and pharmacological aspects involving clinically developed heterocycles that at some point were presented as promising against SARS-CoV-2.

Composites of sulfonated melanin with reduced graphene oxide were synthesized in different concentrations. The new materials were structurally, optically, and electrically characterized to evaluate the effect of rGO on the material properties.

A single-step method for the synthesis of furan-and pyranoquinoline derivatives through multicomponent Povarov reactions between aniline derivatives, benzaldehyde and two different enol ethers (2,3-dihydrofuran and 3,4-dihydropyran) using niobium pentachloride as catalyst under mild conditions, providing good yields and high diastereoselectivity, is described.

The behaviour of the neutral alkynyl complexes trans-[FeBr(L)(depe) 2 ] (L = −C≡C− C(=CH 2)Ph 1a, −C≡C−CPh 2 (H) 1b; depe = Et 2 PCH 2 CH 2 PEt 2) is studied by cyclic voltammetry and the electrochemical P L and E L ligand parameters for the alkynyl ligands are estimated showing that they behave as very strong net electron-donors.