Pd-catalyzed intramolecular C-H activation for the synthesis of fused-1,2,3-triazole quinolines and dihydroquinolines

A Pd-catalyzed, simple, and efficient approach toward structurally diverse fused polycyclic [1,2,3]triazolo[4,5-c]quinoline and 4,5-dihydro-[1,2,3]triazolo[4,5-c]quinoline has been developed. The method is based on intramolecular Pd-catalyzed C-H activation and features operational simplicity, high atom economy, broad substrate scope, excellent yields, and good functional group tolerance. Gram-scale experiments and post-synthetic modifications were performed to extend the synthetic applicability of the proposed methodology and enhance the structural complexity of the obtained derivatives.

Construction of five- and seven-membered rings facilitated by alkyne-azide functionality: access to quinoline fused triazolo-azepines

The synthesis of novel quinoline-fused triazolo-azepine derivatives has been reported using an intramolecular 1,3-dipolar azide-alkyne cycloaddition strategy. This method possesses considerable potential to synthesize five- and seven-membered rings in high yields (65-87%) without the necessity of metal catalysts or additives. Additionally, this methodology was applicable to pyridine and tetralone based adducts to afford triazolo-azepine derivatives. This intriguing chemistry offers numerous advantages, including metal-free and additive-free processes, applicability to gram scale synthesis, high atom economy and easy access to a diverse library of potential pharmacological compounds in high yields.

Recent Advances in the Synthesis of Propargyl Derivatives, and Their Application as Synthetic Intermediates and Building Blocks

The propargyl group is a highly versatile moiety whose introduction into small-molecule building blocks opens up new synthetic pathways for further elaboration. The last decade has witnessed remarkable progress in both the synthesis of propargylation agents and their application in the synthesis and functionalization of more elaborate/complex building blocks and intermediates. The goal of this review is to highlight these exciting advances and to underscore their impact.

Study and application of graphene oxide in the synthesis of 2,3-disubstituted quinolines via a Povarov multicomponent reaction and subsequent oxidation

The carbocatalyzed synthesis of 2,3-disubstituted quinolines is disclosed. This process involved a three-component Povarov reaction of anilines, aldehydes and electron-enriched enol ethers, which gave the substrate for the subsequent oxidation. Graphene oxide (GO) was exploited as a heterogeneous, metal-free and sustainable catalyst for both transformations. The multicomponent reaction proceeded under simple and mild reaction conditions, exhibited good functional group tolerance, and could be easily scaled up to the gram level. A selection of tetrahydroquinolines obtained was subsequently aromatized to quinolines. The multistep synthesis could also be performed as a one-pot procedure. Investigation of the real active sites of GO was carried out by performing control experiments and a by full characterization of the carbon material by X-ray photoelectron spectroscopy (XPS) and solid-state nuclear magnetic resonance (ssNMR).