AlCl3 induced C–N bond formation followed by Pd/C–Cu mediated coupling–cyclization strategy: synthesis of pyrrolo[2,3-b]quinoxalines as anticancer agents

Investigation of TNBC in vitro Antiproliferative Effects of Versatile Pirrolo[1,2-a]quinoxaline Compounds

The triple-negative breast cancer (TNBC) is characterized by a more aggressive nature and poorer prognosis, nowadays none pharmaceutical approach is still available. For this reason, the research of new active compounds and attractive targets represents an interesting field. In this context MDA- MB-231 cell line was selected to evaluate the antiproliferative effects of new [1,2-a]-pyrroloquinoxaline derivatives. The MTT assay revealed that the amine forms of synthesized molecules were more active compared to iminic ones at 72 h of incubation. The antiproliferative effect of the most promising compounds highlighted the formation of autophagic vacuoles.

One-pot synthesis of biologically active 1,2,3-trisubstituted pyrrolo[2,3-b]quinoxalines through a palladium-catalyzed reaction with internal alkyne moieties

Synthesis of 2,3-disubstituted 1-alkylpyrrolo[2,3-b]quinoxalines was accomplished through the reaction of 3-chloroquinoxalin-2-amines with internal alkynes in the presence of Pd(OAc)[Formula: see text], NaOAc, and KOtBu in DMSO. This method afforded desired pyrrolo[2,3-b]quinoxalines in 65-92% reaction yields. The minimum inhibition concentration and minimum bactericidal concentration determinations against Micrococcus luteus and Pseudomonas aeruginosa revealed that some of the synthesized compounds showed the same values compared to tetracycline. These compounds could be used in the future research for the development of new antibiotics.

Use of AlCl3 in Friedel Crafts arylation type reactions and beyond: an overview on the development of unique methodologies leading to N-heteroarenes

An overview on the development of unique methodologies that highlight the use of AlCl₃ in reactions leading to new N-heteroarenes of biological significance is presented.

Ligand-free MCR for linking quinoxaline framework with a benzimidazole nucleus: a new strategy for the identification of novel hybrid molecules as potential inducers of apoptosis

We report a true MCR involving the reaction of N-(prop-2-ynyl)quinoxalin-2-amine derivatives with 2-iodoanilines and tosyl azide in the presence of 10 mol% of CuI and Et3N in DMSO to afford the pre-designed hybrid molecules containing quinoxaline framework linked with a benzimidazole nucleus. The MCR proceeds in the absence of any ligand and/or lateral addition of the catalyst/base affording products within 30 min in good yields, some of which showed encouraging apoptosis inducing properties in zebrafish.

Quinoxaline: a new directing group for ortho C–H alkenylation / intramolecular ortho C–H cycloamination under open air leading to bioactive polynuclear N-heteroarenes

A two-step strategy involving quinoxaline directed the ortho C–H alkenylation/intramolecular ortho C–H cycloamination afforded new PDE4 inhibitors.

Ligand/PTC-free intramolecular Heck reaction: synthesis of pyrroloquinoxalines and their evaluation against PDE4/luciferase/oral cancer cell growth in vitro and zebrafish in vivo

A series of 1,3-disubstituted pyrrolo[2,3-b]quinoxalines has been designed for the potential inhibition of PDE4 without inhibiting luciferase. A ligand/PTC (phase transfer catalyst) free intramolecular Heck cyclization strategy was used to prepare these compounds, some of which showed significant inhibition of PDE4B (IC50≈ 5-14 μM) and growth inhibition of oral cancer cells (CAL 27) but not inhibition of luciferase in vitro. They also showed acceptable safety profiles but no apoptosis in zebrafish embryos.

Transition metal free hydrolysis/cyclization strategy in a single pot: synthesis of fused furo N-heterocycles of pharmacological interest

A transition metal free tandem two-step strategy has been developed involving hydrolysis of 2-chloro-3-alkynyl quinoxalines/pyrazines followed by in situ cyclization of the corresponding 2-hydroxy-3-alkynyl intermediates in a single pot leading to fused furo N-heterocycles as potential inhibitors of sirtuins. A representative compound showed promising pharmacological properties in vitro and in vivo.