Synthesis of 5-Substituted Benzo[h ]quinoline Derivatives via Reactions Involving C(sp 2 )−Br Bond Activation

A substituent-induced post-assembly modification cascade of a metallosupramolecular imine-type Co-complex

Here, we report a reaction cascade employing the substituent-induced post-assembly modification of a Co(iii) complex. Unexpectedly, we found that the (triisopropylsilyl)alkynyl moiety introduced to the Sonogashira reaction with the bromo-functionalized Co(iii) assembly plays a "Trojan horse" role, triggering a subsequent, second step of the cascade, i.e. Co(iii) to Co(ii) reduction. The reported substituent-activated Sonogashira-redox cascade reaction might set a new direction in the construction of specific chemical sensors.

Highly efficient microwave synthesis of rhodanine and 2-thiohydantoin derivatives and determination of relationships between their chemical structures and antibacterial activity

Here we report studies on the synthesis of 12 new heterocyclic derivatives that differ in three structural motifs and the simultaneous evaluation of the impact of these three variables on the biological properties. The examined compounds are based on rhodanine and 2-thiohydantoin cores equipped with hydrogen or carboxymethyl substituents at the N-3 position and linked to a triphenylamine moiety through 1,4-phenylene, 1,4-naphthalenylene and 1,9-anthracenylene spacers at the C-5 position of the heterocycles. All the compounds were synthesized very quickly, selectively and in high yields according to the developed microwave-assisted Knoevenagel condensation protocol, and they were characterized thoroughly with NMR, FT-IR and ESI-HRMS techniques. The derivatives were tested for their activity against selected strains of Gram-positive and Gram-negative bacteria and yeast. Two compounds showed good activity against Gram-positive bacteria, and all of them showed low cytotoxicity against three cell lines of the human immune system. Based on membrane permeability assays it was demonstrated that the active compounds do not penetrate the cell membrane, and thus they must act on the bacterial cell surface. Finally, we proved that the evaluated structure modifications had a synergistic effect and the simultaneous presence of a 1,4-phenylene spacer and carboxymethyl group at N-3 caused the highest boost in antimicrobial activity.

An efficient microwave-assisted synthesis of rhodanine and 2-thiohydantoin derivatives, and the correlation between their chemical structure and biological properties is reported.

An efficient 3-acylquinoline synthesis from acetophenones and anthranilviaC(sp3)–H bond activation mediated by Selectfluor

An efficient method for the synthesis of 3-functionalized quinolines from commercially available acetophenones and anthranil has been described. Selectfluor propels the C(sp³)–H bond activation of the acetophenones and aza-Michael addition of anthranil resulting in annulated 3-acylquinolines in moderate to high yields. DMSO acts not only as a solvent but also as a one carbon donor in the reaction.

An efficient method for the synthesis of 3-functionalized quinolines from acetophenones and anthranil mediated by Selectfluor was achieved.