Surya Narayana Maddila

Mn doped ZrO2 as a green, efficient and reusable heterogeneous catalyst for the multicomponent synthesis of pyrano[2,3-d]-pyrimidine derivatives

A simple and an efficient method has been developed for the one-pot multicomponent synthesis of pyrano[2,3-d]-pyrimidine derivatives. This was achieved through the condensation reaction between dimethylbarbituric acid, aromatic aldehyde and malononitrile in the presence of a Mn/ZrO2 heterogeneous catalyst with ethanol/water mixture as solvent for only 1 hour. Further advantages of this synthesis methodology include excellent yields, mild reaction conditions, atom economy, environmentally friendliness, reusable catalyst and no need for chromatographic separations.

Ceria–Vanadia/Silica‐Catalyzed Cascade for C−C and C−O Bond Activation: Green One‐Pot Synthesis of 2‐Amino‐3‐cyano‐4H‐pyrans

Abstract We designed a ceria–vanadia/silica (Ce–V/SiO2) heterogeneous catalyst and used it for the green and efficient synthesis of 2‐amino‐3‐cyano‐4H‐pyran derivatives. The green reaction was a multicomponent one‐pot condensation of 5,5‐dimethylcyclohexane‐1,3‐dione, aromatic aldehyde, and malononitrile in an eco‐compatible solvent (ethanol). The catalyst was synthesized and fully characterized by powder X‐ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and Brunauer–Emmett–Teller (BET) surface area analysis. The reported procedure offers a number of advantages including decreased reaction times, mild conditions, high yields, operational simplicity, and environmentally benign and simple work‐up procedures. Furthermore, the catalyst is economical, fully recyclable, and reusable for over five runs while preserving its high activity. The synthesized 2‐amino‐3‐cyano‐4H‐pyran products can later be used for pharmaceutical purposes.

Decorated multi-walled carbon nanotubes with Sm doped fluorapatites: synthesis, characterization and catalytic activity

Novel and sustainable heterogeneous catalysts, namely, multi-walled carbon nanotubes (MWCNT) decorated with Sm doped fluorapatite nanocomposites (MWCNT/Sm-FAp) were prepared by facile co-precipitation method using glutamic acid as an organic modifier with different loadings of Sm (1%, 2%, 3%, 5%, and 7%). The nanocomposites were characterized by powder X-ray diffraction (PXRD), Fourier transform infra-red spectroscopy (FT-IR), microscopic techniques (FESEM, HRTEM), energy dispersive X-ray spectrometer (EDX) and Brunauer–Emmett–Teller method (BET) surface area, and thermogravimetric analysis (TGA). The SEM and TEM results confirmed that with varying Sm loading, the nanocomposites attained varied particles sizes in the nano-grade scale with different morphologies. The N2 adsorption isotherm results showed that the BET surface area of nanocomposites enhanced from MWCNT/1% Sm-FAp (47.60 m2 g−1) to MWCNT/7% Sm-FAp (62.00 m2 g−1). The robust catalytic behavior of the MWCNT/Sm-FAp nanocomposites impressively showcased the esthetic results in the highly selective synthesis of the 1,2,4-triazole moiety from aromatic aldehydes. The catalytic efficiency increased with rise in Sm% from 1% to 5% in the nanocomposite. With MWCNTs/5% Sm-FAp nanocomposite as the catalyst, the reaction recorded 96% yield of triazole in short reaction times (10 min).

Novel iron doped calcium oxalates as promising heterogeneous catalysts for one-pot multi-component synthesis of pyranopyrazoles

The co-precipitation method using a surface modifier, glutamic acid was employed in the design of iron doped calcium oxalates (Fe-CaOx). Fe-CaOx with diverse iron loading (0.5–3.0 mmol) were prepared and their phase purity and surface features were examined by X-ray powder diffraction (XRD), Fourier transform infrared (FT-IR), electron microscopy (SEM, TEM), energy dispersive X-ray (EDX), Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES), N2-sorption, thermal and fluorescent analysis. The Fe-CaOx materials proved excellent as catalysts in the one-pot syntheses of eight 2,4-dihydro pyrano[2,3-c]pyrazole derivatives via four component condensation of aromatic aldehydes, malononitrile, hydrazine hydrate and dimethyl acetylenedicarboxylate in ethanol with impressive yields (92–98%) in short reaction times (<20 min). The 2.0 mmol loaded iron in Fe-CaOx showed the finest catalytic performance with 98% yield in 10 min compared to other loadings. The stability, ease of separation, and reusability for up to six cycles of Fe-CaOx make it an environmentally friendly and cost-effective viable choice for the value-added organic transformations.

A facile, efficient, and sustainable chitosan/CaHAp catalyst and one-pot synthesis of novel 2,6-diamino-pyran-3,5-dicarbonitriles

A simple and versatile one-pot three-component synthetic protocol is devised for heterocycles, viz. 2,6-diamino-4-substituted-4H-pyran-3,5-dicarbonitrile derivatives, in short reaction times (

Synthesis, Molecular Docking Study and in vitro Anticancer Activity of Tetrazole Linked Benzochromene Derivatives.

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Ozone-driven photocatalyzed degradation and mineralization of pesticide, Triclopyr by Au/TiO2

≈30 min) at room temperature using ethanol as a solvent. This method involves the three-component reaction of malononitrile, substituted aldehydes, and cyanoacetamide catalyzed by chitosan-doped calcium hydroxyapatites (CS/CaHAps) giving good to excellent yields (86–96%). Twelve new pyran derivatives (4a–l) were synthesized and their structures were established and confirmed by different spectroscopic methods (