Faculty Publications
Permanent URI for this communityhttps://idr.nitk.ac.in/handle/123456789/18736
Publications by NITK Faculty
Browse
3 results
Search Results
Item A straightforward preparation of levulinic esters from biorenewable levulinic acid using methanesulfonic acid supported on silica gel (MSA-SG) as an efficient heterogeneous catalyst(Elsevier Ltd, 2023) Vinod, N.; Bandibairanahalli Onkarappa, S.; Madhwaraj Girija, V.; Dutta, S.The present work reports methanesulfonic acid supported on silica gel (MSA-SG) as an inexpensive heterogeneous solid acid catalyst for the high-yielding production of various alkyl levulinates from biomass-derived levulinic acid. The catalyst was characterized by powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy with energy-dispersive X-ray analysis (SEM-EDX). The reactions were conducted in a batch-type glass pressure reactor under conventional heating. The esterification reaction was optimized on temperature, duration, and catalyst loading. The optimized reaction conditions (120 °C, 8 h, 8 wt% MSA-SG) afforded methyl- to butyl levulinate in excellent isolated yields (≥90 %). The catalyst was filtered, and the products were purified by simply evaporating the excess alcohol reagent. © 2022Item Recent advances in the preparation of levulinic esters from biomass-derived furanic and levulinic chemical platforms using heteropoly acid (HPA) catalysts(Elsevier B.V., 2021) Bhat, N.S.; Mal, S.S.; Dutta, S.The esters of biomass-derived levulinic acid (LA) have several potential applications, including cleaner-burning fuel additive, green solvent, fragrance ingredient, and a renewable chemical intermediate for downstream value addition. The levulinic esters (LEs) can be prepared by the acid-catalyzed alcoholysis of the biomass-derived furanic and levulinic chemical platforms such as LA, furfuryl alcohol (FAL), 5-(hydroxymethyl)furfural (HMF), and angelica lactone (AGL). The acid-catalyzed deconstruction of carbohydrates in an alcoholic medium affords the one-pot preparation of LEs. Choosing the right catalyst is of paramount importance for synthesizing LEs from both the economic and environmental perspectives. In this regard, heteropoly acids (HPAs), a class of polyoxometalates (POMs) bearing protons as the counter cation, have found widespread applications as acid catalysts in various organic transformations. HPAs are blessed with conducive properties such as controlled Brønsted and Lewis acidity, high thermal stability, robust structural features, non-toxic nature, tunable solubility, and less corrosiveness. Over the past several years, HPAs have found extensive applications as efficient and environment-friendly catalysts in biorefinery operations, including the synthesis of LEs. At this juncture, it is imperative to ascertain the achievements in this field to date and re-evaluate the challenges. This review attempts to provide up-to-date information about the preparation of LEs using HPA-based catalysts, critically analyze the literature cited, draw conclusions, and propose future prospects. © 2021 Elsevier B.V.Item Sustainable synthesis of novel 3-(2-furyl)acrylic acids and their derivatives from carbohydrate-derived furfurals by chemical catalysis(Springer Science and Business Media Deutschland GmbH, 2024) Prabhakar, P.S.; Dutta, S.This work reports the renewable synthesis of 3-(2-furyl)acrylic acid and its novel-substituted derivatives, with potential applications as sustainable chemical building units, starting from carbohydrate-derived 5-substituted-2-furaldehydes and malonic acid employing various organocatalysts. Piperidinium acetate as the catalyst afforded good to excellent isolated yields of the acrylic acids under solvent-free conditions. The substituted 3-(2-furyl)acrylic acids were esterified using MeSO3H/SiO2 as a heterogeneous acid catalyst. The 3-(2-furyl)acrylic acids containing acid-sensitive functional groups on the furan ring were esterified by dimethyl carbonate as the sustainable reagent by base-catalyzed transesterification reaction. Moreover, the olefinic group was selectively reduced by catalytic hydrogenation using 5%Pd/C as the catalyst. The catalytic processes were optimized on various reaction parameters, and the synthesized compounds were characterized by FTIR, NMR (1H, 13C), and elemental analysis. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2023.