Soora Harinath Jayaprakash

Polyethylene glycol in water: a simple and environment friendly medium for C–P bond formation

A simple and highly efficient protocol for C–P bond formation under catalyst free conditions at an ambient temperature is reported by using polyethylene glycol in water as an efficient recyclable medium without using any organic co-solvent or additive.

Design, Synthesis, Antioxidant, and Anti‐Breast Cancer Activities of Novel Diethyl(alkyl/aryl/heteroarylamino)(4‐(pyridin‐2‐yl)phenyl)methylphosphonates

A series of new diethyl(alkyl/aryl/heteroarylamino)(4‐(pyridine‐2‐yl)phenyl)methylphosphonates (4a–t) were synthesized via three‐component Kabachnik–Fields reaction of 4‐(pyridin‐2‐yl)benzaldehyde, diethylphosphite and various primary amines, catalyzed by cupric acetate monohydrate [Cu(OAc)2 · H2O] under solvent‐free and microwave irradiation conditions. Their computational docking analysis supported them as good therapeutic agents to the breast cancer aromatase enzyme and ascertained 4a, 4h, 4m, 4n, and 4t as potential molecules with good binding affinities varying from −9.0 to −9.6 kcal/mol and containing the 4‐(pyridine‐2‐yl)phenyl moiety as a pharmacophore. Their in vitro screening performed for the anti‐cell proliferation activity against MBC‐MCF7 cells by MTT and Trypan blue assays confirmed 4m, 4n, and 4q as promising compounds to sustain a low percentage of cell viability at 20 µg/mL concentration. These compounds were also evaluated for their antioxidant activity by the DPPH method and the results established that compounds 4m, 4n, and 4q show around 10% higher activity than the standard antioxidant ascorbic acid.

Silica-Supported Tungstic Acid Catalyzed Synthesis and Antioxidant Activity of α-Hydroxyphosphonates

GRAPHICAL ABSTRACT Abstract A green and efficient method has been accomplished for the synthesis of α-hydroxyphosphonates using silica-supported tungstic acid (STA) as a heterogeneous catalyst under solvent-free conditions at ambient temperature. The compounds obtained were characterized by spectral and analytical studies and screened in vitro for the antioxidant activity by four methods viz., DPPH free radical scavenging assay, hydrogen peroxide scavenging assay, NO method, FRAP method. The results indicated that the title compounds are potential antioxidants and are comparable to the antioxidant property of the standard ascorbic acid.

PAA-SIO2 Catalyzed Synthesis, Uv Absorption, and Fluorescence Emission Studies of Diethyl (Aryl/Hetero Aryl Amino)(Pyren-1-Yl)Methylphosphonates

GRAPHICAL ABSTRACT Abstract A simple, efficient, and one-pot protocol for the synthesis of some new pyrenyl-α-aminophosphonates (4a–l) by Kabachnik-Fields reaction using silica supported polyacrylic acid (PAA-SiO2) as a new reusable heterogeneous catalyst under neat conditions has been developed. All the synthesized compounds were investigated for the exhibition of their photophysical properties in the UV-Visible region. The absorption and emission maxima and specifically blue and red shifts were identified with respect to the substituents present.

Ionic Liquid–Promoted Phospha-Michael Reaction: Convenient Access to β-Nitrophosphonates

Abstract A convenient and mild procedure is developed for β-nitrophosphonates via phospha-Michael addition of phosphites to nitrostyrene at room temperature in the presence of 1,8-diazabicyclo-[5.4.0]undec-7-ene (DBU)–based ionic liquid [DBUH][OAc]. The operational simplicity, convenient workup, and reusability of the ionic liquid make this method attractive. GRAPHICAL ABSTRACT

Tween 20-/H2O Promoted Green Synthesis, Computational and Antibacterial Activity of Amino Acid Substituted Methylene Bisphosphonates

GRAPHICAL ABSTRACT Abstract A green synthesis of amino acid-substituted methylene bisphosphonates (4a-j) is achieved via a one-pot, three-component reaction of dialkylphosphite, triethyl orthoformate, and various amino acids catalyzed by Tween 20 in aqueous medium. The synthesized compounds were characterized by infrared spectroscopy, nuclear magnetic resonance (1H, 13C, and 31P), mass spectra, and elemental analysis. These were screened for in vitro antibacterial activity against clinically isolated bacteria Klebsiella pneumonia, Pseudomonas aeruginosa (Gram –ve), and Staphylococcus aureus, Bacillus subtilis (Gram +ve). Among all the compounds, 4a and 4d showed higher activity against all bacterial strains compared with standard ciprofloxacin. To further support the work, molecular docking studies against the bacterial target enzyme, Type IIA topoisomerase revealed that some of the lead molecules 4j (–7.4 kcal/mol), 4e (–7.1 kcal/mol), 4a (–6.8 kcal/mol), and 4d (–6.8 kcal/mol) showed good protein–ligand interactions.

TiO 2 -SO 4 2- Catalyzed Synthesis and Antimicrobial Activity / Molecular Docking Studies of β-Indolylnitroalkanes

Michael addition of indole derivatives with various substituted nitrostyrenes to yield β- indolylnitroalkanes is accomplished effectively under solvent free conditions using TiO2-SO4(2-) as efficient catalyst at 60 º C. All the synthesized compounds were screened for their antibacterial activity through in silico and in vitro methods. The molecular docking studies against FabH enzyme, a potential drug target of bacterial fatty acid biosynthetic pathway indicated the scope of developing them a new class of antimicrobial agents. Among the title compounds, 5h exhibited the highest dock score and the highest antibacterial activity when compared with other compounds and the standard drug Ampicillin. In addition, the compounds 5d, 5e, 5g, 5h, 5i, 5j and 5l showed significant inhibitory activity at different dose concentrations under in vitro conditions against the specified bacterial strains thus qualifying for further clinical evaluation so that they can be used as effective anti-bacterial agents.

Sodium Perborate: A Facile Catalyst for Allylation of Active Centers

GRAPHICAL ABSTRACT An efficient and ecofriendly allylation of O-H, N-H, and C-H groups has been achieved successfully with the reaction of allyl bromide by using sodium perborate as a new catalyst in aqueous media. The advantage of this method is operationally simple, short reaction time, good yield, and simple workup conditions over the previously reported conventional methods such as amination, oxyalkylation reactions of allyl bromide, and Friedel–Crafts allylation chemistry.