Ashok Konala

Palladium-Catalyzed Tandem C–H Functionalization/Cyclization Strategy for the Synthesis of 5-Hydroxybenzofuran Derivatives

A palladium-catalyzed benzoquinone C-H functionalization/cyclization strategy with terminal alkynes was employed for the synthesis of some biologically relevant 2,3-disubstituted 5-hydroxybenzofuran derivatives. The benzoquinone acts as a reactant as well as an oxidant. During the process, an additional alkyne functionality can be introduced at the C3 position of the benzofuran. Base, ligand, and external oxidant are not required in this protocol.

Synthesis of Biologically Active Indenoisoquinoline Derivatives via a One-Pot Copper(II)-Catalyzed Tandem Reaction

A concise route for the synthesis of indenoisoquinoline derivatives from 2-iodobenzamide and 1,3-indanedione derivatives in the presence of copper(II) chloride and cesium carbonate in acetonitrile solvent is reported. A wide variety of 2-iodobenzamide derivatives and indandiones could be used to synthesize indenoisoquinoline derivatives and other fused indenoisoquinoline in moderate to good yields. This methodology was adapted for the one-step synthesis of a series of clinically active topoisomerase I inhibitors such as NSC 314622, LMP-400, LMP-776.

Synthesis of Benzopyridoindolone Derivatives via a One-Pot Copper Catalyzed Tandem Reaction of 2-Iodobenzamide Derivatives and 2-Iodobenzylcyanides

An efficient approach for the synthesis of benzo-fused pyridoindolone derivatives via a one-pot copper catalyzed tandem reaction of 2-iodobenzamides with 2-iodobenzylcyanides has been developed. Using this protocol, benzo-fused pyridoindolone derivatives are obtained in high yields in a relatively short period of time under mild reaction conditions. To the best of our knowledge, this is the first approach where one can synthesize free indole N-H benzo-fused pyridoindolones. Also, both indole and pyridone cores are constructed during the course of the reaction. The methodology shows good functional group tolerance and allows synthesis of thiophene-fused pyridoindolones and fused indolobenzonaphthyridone derivatives.

Synthesis of 3-arylindole derivatives from nitroalkane precursors

3-Arylindole derivatives were synthesized by Cu(I) catalysed intramolecular Ullmann coupling of 2-bromoarylaminoalkanes. 2-Bromoarylaminoalkanes were synthesized from 2-bromoarylnitroalkanes, which in turn prepared through AlCl3-mediated Friedel–Crafts alkylation of bromo-substituted β-nitrostyrenes and arenes.

Synthesis of functionalized unsymmetrical 1,3-butadiene-3-yne derivatives from β-halo styrene derivatives and their application in the synthesis of trisubstituted pyridines

An approach for the synthesis of functionalized unsymmetrical 1,3-butadiene-3-yne derivatives is reported starting from β-halo styrene and phenyl acetylene derivatives in the presence of PdCl2 and CuI catalysts. Functional groups such as aldehyde, cyano and ester groups are well tolerated and afford the desired functionalized dienynes. Further, these 1,3-buta-diene-3-yne derivatives are utilized for the synthesis of novel trisubstituted pyridine derivatives.

Nanomaterial grafted Microfluidic Columns for Biomolecule Separation at Analytical Scale

Abstract Rapid, efficient separation and accurate identification of valuable biomolecules like nucleic acids, proteins, and polysaccharides from complex mixtures like serum, milk, and plant extracts require reliable analytical tools [1]. The degree of complexity is enhanced when the desired separation has to be performed with limited sample volumes and the presence of target analytes (e.g., a potential biomarker for proteomics and molecular diagnostics) are in micro and nano levels. In these cases, conventional chromatography techniques fail due to their limitations like the requirement of large sample volumes and process times. The miniaturization concept has the key advantage of requiring small sample volumes and efficient and rapid separation. However, in terms of chromatography applications, they possess major limitations like adsorption capacity due to low surface area. The use of nanomaterials (nanoparticles, nanofibers, and nanowires), which possess a high surface area and diverse functional groups, for modification will help to overcome this limitation.

Synthesis of Polysubstituted Cyclopentene and Cyclopenta[b]carbazole Analogues from Unsymmetrical 4-Arylidene-3,6-diarylhex-2-en-5-ynal and Indole Derivatives via an Iodine Mediated Electrocyclization Reaction

An efficient method for the synthesis of polysubstituted cyclopentene and cyclopenta[ b]carbazole derivatives through the iodine-promoted electrocyclization of substituted indoles and 4-arylidene-3,6-diarylhex-2-en-5-ynal derivatives is reported. Polysubstituted cyclopentene derivatives were produced through 4π electrocyclization reactions with indole, 7-methylindole, and 5-bromoindole as coupling partners, whereas cyclopenta[ b]carbazole derivatives were produced via 6π electrocyclization in the case of methoxy (-OMe)-substituted indoles. The methods reported herein diastereo- and regioselectively proceed under straightforward and mild conditions.