Ramesh Katla

A new, efficient and recyclable [Ce(L-Pro)]2(Oxa) heterogeneous catalyst used in the Kabachnik–Fields reaction

Herein we introduce a new catalyst for the Kabachnik–Fields reaction, [Ce(L-Pro)]2(Oxa), using a very accessible, simple and efficient methodology for α-aminophosphonate synthesis using an aromatic aldehyde, an aromatic amine and diphenyl phosphite. This procedure was developed using a low catalyst loading of cerium(III) prolinate and it has allowed for the recycling of the catalyst.

β-Cyclodextrin as a recyclable catalyst: aqueous phase one-pot four-component synthesis of polyfunctionalized pyrroles

An elegant, mild and straightforward methodology was explored for the first time towards the synthesis of polyfunctionalized pyrroles using β-cyclodextrin as a reusable supramolecular catalyst in aqueous medium. The present method provides various diversely substituted pyrroles from the commercially available synthons in good to excellent yields. The advantages of this novel protocol are use of environmentally benign reaction medium and recyclability of β-cyclodextrin over the existing methods.

[Ce(L-Pro)2]2 (Oxa) as a heterogeneous recyclable catalyst: synthesis of pyrazoles under mild reaction conditions

We developed a novel and highly efficient protocol for the synthesis of important pyrazole derivatives by using some 1,3-dicarbonyl compounds and phenyl hydrazines via a one-pot protocol. As a recyclable heterogeneous catalyst, we used [Ce(L-Pro)2]2 (Oxa). In addition, the catalyst is recyclable, the proline is economically viable and readily available in both enantiomeric forms and the catalyst is insoluble in almost all solvents and may be easily filtered off from the reaction medium. Moreover, this new synthetic protocol features high conversion, short reaction times, a straightforward procedure and cleaner reaction profiles.

Molecular interaction of novel benzothiazolyl triazolium analogues with calf thymus DNA and HSA-their biological investigation as potent antimicrobial agents

The binding behaviour between calf thymus DNA and synthesized benzothiazolyl triazolium derivatives as potent antimicrobial agents was explored by means of spectroscopic applications together with molecular docking study at the sub-domain IIA, binding site I of human serum albumin (HSA). Most of the synthesized derivatives presented significant antimicrobial inhibition when compared with the clinical Norfloxacin, Chloromycin, and Fluconazole. In particular, compound 5q presented efficient anti-Bacillus subtilis, anti-Escherichia coli, anti-Salmonella typhi, and anti-Psuedomonas aeruginosa activity with low MIC values of 2-8 μg/mL which were relatively superior to the reference drugs. The preliminarily investigation of interaction studies with calf thymus DNA demonstrated that the most active compound 5q could effectively intercalate into DNA to form 5q-DNA complex. Further investigations revealed that human serum albumin could effectively transport compound 5q while molecular modelling studies with good docking score showed that hydrophobic interactions as well as hydrogen bonds played a significant role in the interaction of compound 5q with HSA. In addition, the cytotoxic investigation carried out on four different cancerous cell lines (3 human cell lines and 1 murine cell lines) by MTT assay presented that compound 5n is active against MDA cell lines with IC50 values less than 100 μg/mL.

Lipase catalyzed 1,2-addition of thiols to imines under mild conditions

This is the first report of enzymes used as biocatalysts for a 1,2-sulfur addition. In this study, we describe the synthesis of N,S-acetals using an environmentally friendly process with low catalyst loading and in short reaction times using porcine pancreatic lipase, chymosin, and bovine serum albumin (BSA). The hydrogen bond between the enzyme and the N-Boc imine is a key factor in this reaction.