An improved microwave assisted protocol for Yonemitsu-type trimolecular condensation

Recent advances in the application of indoles in multicomponent reactions

Indoles are some of the most versatile and common nitrogen-based heterocyclic scaffolds and are frequently used in the synthesis of various organic compounds. Indole based compounds are very important among heterocyclic structures due to their biological and pharmaceutical activities. The last decade, in particular, has witnessed considerable activity towards the synthesis of indole derivatives due to the possibilities for the design of polycyclic structures by the incorporation of multiple fused heterocyclic scaffolds in an attempt to achieve promising new heterocycles with chemical and biomedical relevance. In this study, we provide an overview on recent applications of indole in the multicomponent reactions for the synthesis of various heterocyclic compounds during the period of 2012 to 2017.

Diindolylmethane Derivatives: Potent Agonists of the Immunostimulatory Orphan G Protein-Coupled Receptor GPR84

The G_i protein-coupled receptor GPR84, which is activated by (hydroxy)fatty acids, is highly expressed on immune cells. Recently, 3,3'-diindolylmethane was identified as a heterocyclic, nonlipid-like GPR84 agonist. We synthesized a broad range of diindolylmethane derivatives by condensation of indoles with formaldehyde in water under microwave irradiation. The products were evaluated at the human GPR84 in cAMP and β-arrestin assays. Structure-activity relationships (SARs) were steep. 3,3'-Diindolylmethanes bearing small lipophilic residues at the 5- and/or 7-position of the indole rings displayed the highest activity in cAMP assays, the most potent agonists being di(5-fluoro-1H-indole-3-yl)methane (38, PSB-15160, EC₅₀ 80.0 nM) and di(5,7-difluoro-1H-indole-3-yl)methane (57, PSB-16671, EC₅₀ 41.3 nM). In β-arrestin assays, SARs were different, indicating biased agonism. The new compounds were selective versus related fatty acid receptors and the arylhydrocarbon receptor. Selected compounds were further investigated and found to display an ago-allosteric mechanism of action and increased stability in comparison to the lead structure.

Heterogenization of amine-functionalized ionic liquids using graphene oxide as a support material: a highly efficient catalyst for the synthesis of 3-substituted indoles via Yonemitsu-type reaction

Heterogenization of amine functionalized ionic liquid and its application as an efficient and recyclable catalyst.

One-pot three-component protocol for the synthesis of indolyl-4H-chromene-3-carboxamides as antioxidant and antibacterial agents

A series of newly synthesized 4-(1H-indol-3-yl)-2-methyl-N-phenyl-4H-chromene-3-carboxamide derivatives catalyzed by 1,4-Diazabicyclo [2.2.2]octane (DABCO) (30 mol%) at room temperature.

Recent advances and perspectives in the synthesis of bioactive coumarins

The impressive pharmacological properties shown by a number of coumarins have led to extraordinarily large emphasis being placed on the design of more efficient and greener synthetic procedures to produce them.