Zirconium(IV)-catalyzed one-pot synthesis and oxidation of bis- and tris(indolyl)methanes into conjugated chromophores as new pH indicators or calorimetric chemosensors for transition metals

An approach to unsymmetrical 3,3′-diindolylmethanes through Pd-catalyzed cascade Heck cyclization of allenamides and o-ethynylanilines

A highly efficient synthesis of unsymmetrical 3,3′-diindolylmethanes has been developed by palladium-catalyzed cascade Heck/cyclization reaction.

Bisindolization Reaction Employing Phthalimide-N-sulfonic Acid as an Efficient Catalyst

Background:

Bis(indolyl) methanes (BIMs) have a wide spectrum of applications in biomedicine and agriculture as well as are present in natural products. These bisheterocyclic compounds possess vast pharmacological, including antifungal, antitubercular, anti-inflammatory, antibacterial, anticancer, anticonvulsant, antibiotic, antiviral, antimalarial, analgesic, and antidiabetic properties. BIMs scaffolds have also been employed as selective optical chemosensors for detection of some anions and cations with the naked eye. Because of the importance of these bisheterocycles, various methods have been reported for their synthesis through reaction of indole derivatives and aldehydes or ketones. Therefore, the synthesis of BIMs through different methodologies has received widespread attention in the field of organic synthesis and medicinal chemistry.

Objective:

In this study, the catalytic activity of phthalimide-N-sulfonic acid (PISA) as an efficient and safe solid acidic organocatalyst toward the synthesis of BIMs derivatives in ethanol is described.

Methods:

Indole derivatives (2 mmol), aryl/heteroaryl aldehydes (1 mmol), and PISA (10 mol%) were mixture in ethanol. The reaction mixture was stirred at room temperature for the appropriate times. After workup and separation of catalyst, the corresponding heterocyclic products were obtained through recrystallization from hot ethanol.

Results:

The BIMs derivatives were easily obtained via Bisindolization Reaction (BIR) of two indoles (2-methylindole and indole) with a series of aryl and heteroaryl aldehydes. The BIR was efficiently catalyzed at room temperature using PISA as an excellent organocatalyst under optimized reaction conditions.

Conclusion:

The reactions were implemented in simple manner and were completed within acceptable reaction times. The expected BIM products were obtained in satisfactory yields. The catalyst can be recovered and reused several times in the template reaction. This approach provides the benefits of convenience, simple operational procedure, no use of hazardous organic solvents, cheapness and ease of preparation of catalyst.

Investigation of new indole derivatives of bovine serum albumin using spectroscopic and molecular docking techniques

We investigated the interaction of two derivatives of bis (indolyl) methane with bovine serum albumin (BSA) using spectroscopic and molecular docking calculations. Fluorescence quenching measurements revealed that the quenching mechanism was static. Fӧrster energy transfer measurements, synchronous fluorescence spectroscopy and docking studies demonstrated that both bis(indolyl)methanes bound to the Trp residues of BSA. The docking study confirmed that both bis(indolyl)methanes form hydrogen bonds and van der Waals interactions with BSA. Our molecular docking study indicated that the compounds are located within the binding pocket of subdomains IIB and IB of BSA. Fourier transform infrared spectroscopy demonstrated that both bis(indolyl)methane derivatives can interact with BSA and can affect the secondary structure of BSA.

Synthesis, characterization and photophysical properties of some 3,3′-bisindolyl(aryl)methanes

A series of 3,3′-bisindolyl(aryl)methanes were synthesized and fully characterized by a combination of¹H and¹³C NMR spectroscopy and in one case using X-ray crystallography.