Mandelic Acid: An Efficient Organo-catalyst for the Synthesis of 3-substituted-3- Hydroxy-indolin-2-ones and Related Derivatives in Aqueous Ethanol at Room Temperature

The Synthesis of 2,2-BIS(1-INDOL-3-YL)Acenaphthylene-1(2)-Ones Using Nanocatalysis: Fluorescent Sensing for Cu2+ Ions

2,2-bis(1H-indol-3-yl)acenaphthylene-1(2H)-ones were synthesised by the reaction of acenaphthenequinone and 2 equivalents of indole using Fe3O4@SiO2@Si-Pr-NH-CH2CH2NH2 as the basic magnetic nanocatalyst, assembled under greener and sustainable conditions in high purity and yields. Furthermore, the photoluminescence properties of 2,2-bis(2-methyl-1H-indol-3-yl)acenaphthylene-1(2H)-one were exploited for the sensing of copper ions in the mixed solvent systems comprising H2O and CH3CN in excitation wavelength at 410 nm with a detection limit of 9.5 ∙ 10–6 M.

Lawsone (2-hydroxy-1,4-naphthaquinone) derived anticancer agents

2-Hydroxy-1,4-naphthaquinone, commonly known as lawsone, represents an extremely important biologically active naturally occurring compound. It can easily be isolated from Lawsonia inermis (henna) tree leaf extract. Last decade has seen tremendous applications of lawsone as a starting component for the preparation of various organic scaffolds. Many of these synthesized scaffolds showed a wide range of biological activities including potential activities towards several cancer cell lines. This review deals with diverse synthetic methods of lawsone derived scaffolds and their screening against different anti-cancer cell lines along with promising results.

Preparation of Tetrasubstituted Bis(3-indolyl)methanes from Indoles and Acetophenes Using 1,3-Dibromo-5,5-dimehtylhydantoin as an Efficient Catalyst

Abstract:

A new process that could efficiently prepare tetrasubstituted bis(3-indolyl)methanes from various indoles and acetophenones with 1,3-Dibromo-5,5-dimehtylhydantoin(DBDMH) as a catalyst was reported. The effects of catalysts, solvents, and reaction temperature were investigated. Under the optimal condition, most of the tetrasubstituted bis(3-indolyl)methanes were obtained in 90–99% yields.

A General Method for the Synthesis of 11H-Indeno[1,2-B]Quinoxalin- 11-Ones and 6H-Indeno[1,2-B]Pyrido[3,2-E]Pyrazin-6-One Derivatives Using Mandelic Acid as an Efficient Organo-Catalyst at Room Temperature

Aims:

Synthesis of 11H-indeno[1,2-b]quinoxalin-11-ones as well as 6H-indeno[1,2-b]pyrido[3,2-e]pyrazin-6-one derivatives under greener conditions.

Background:

Quinoxaline and related skeletons are very common in naturally occurring bioactive compounds.

Objective:

Design a facile, green and organo-catalyzed method for the synthesis of 11H-indeno[1,2-b]quinoxalin-11-ones as well as 6H-indeno[1,2-b]pyrido[3,2-e]pyrazin-6-one derivatives.

Methods:

Both the scaffolds were synthesized via the condensation of ninhydrin and o-phenylenediamines or pyridine-2,3-diamines respectively by using a catalytic amount of mandelic acid as an efficient, commercially available, low cost, organo-catalyst in aqueous ethanol at room temperature.

Results:

Mild reaction conditions, use of metal-free organocatalyst, non-toxic solvent, ambient temperature, and no column chromatographic separation are some of the notable advantages of our developed protocol.

Conclusion:

In conclusion, we have developed a simple, mild, facile and efficient method for the synthesis of structurally diverse 11H-indeno[1,2-b]quinoxalin-11-one derivatives via the condensation reactions of ninhydrin and various substituted benzene-1,2-diamines using a catalytic amount of mandelic acid as a commercially available metal-free organo-catalyst in aqueous ethanol at room temperature. Under the same optimized reaction conditions, synthesis of 6H-indeno[1,2-b]pyrido[3,2-e]pyrazin-6-one derivatives was also accomplished with excellent yields by using pyridine-2,3-diamines instead of o-phenylenediamine.