01424nas a2200241 4500008004100000022001400041245014100055210006900196260000900265300001000274490000800284520057700292653001300869653001300882653002900895653003200924653001500956100001800971700001800989700001901007700002501026856013101051 2019 eng d a1566-736700aPyridine immobilised on magnetic silica as an efficient solid base catalyst for Knoevenagel condensation of furfural with acetyl acetone0 aPyridine immobilised on magnetic silica as an efficient solid ba cMAY  a81-850 v1243 a

Novel heterogeneous pyridine immobilised magnetic silica (Fe3O4@SiO2-Py) was found to be an efficient, greener and heterogeneous solid base catalyst for the Knoevenagel condensation of furfural with acetylacetone under optimized reaction conditions. The Knoevenagel condensation product 3-(2-furylmethylene)-2,4-pentanedione (FMP), a jet fuel precursor, was produced in high yield of 85% with 94% conversion of furfural at 100 degrees C within a period of 4 h. Fe3O4@SiO2-Py catalyst showed excellent stability and recyclability without losing its initial activity.

10afurfural10aJet fuel10aKnoevenagel condensation10aSilica immobilised pyridine10aSolid base1 aTarade, Komal1 aShinde, Suhas1 aSakate, Sachin1 aRode, Chandrashekhar uhttps://library.ncl.res.in/content/pyridine-immobilised-magnetic-silica-efficient-solid-base-catalyst-knoevenagel-condensation02024nas a2200241 4500008004100000022001400041245011800055210006900173260000900242300001200251490000600263520120900269653003301478653001601511653001501527653002301542653001401565100001801579700001801597700001801615700002501633856012401658 2020 eng d a2365-654900aIntegration of heterogeneous acid and base catalysis for clean synthesis of jet-fuel precursor from carbohydrates0 aIntegration of heterogeneous acid and base catalysis for clean s cJAN  a392-4000 v53 a

C-12 branched alkane fuel precursor was produced from carbohydrates using an efficient integrated solid acid and base catalysis approach involving: i) isomerisation-dehydration of carbohydrates to 5-(hydroxymethyl)furfural (HMF) over solid acid catalyst having both Lewis and Bronsted sites) in a biphasic MIBK (methylisobutylketone): water + DMSO solvent system and ii) Claisen-Schmidt condensation of crude HMF with MIBK over solid base catalyst. Initially, high yield of jet fuel precursor, (E)-1-(5-(hydroxymethyl)furan-2-yl)-5-methylhex-1-en-3-one from pure HMF and MIBK was achieved over basic CaMgAl(231) catalyst. The glucose dehydration to HMF was optimized in biphasic MIBK: H2O-NaCl: DMSO (8:1.5:0.5; v/v/v) system, with complete glucose conversion and 42% HMF yield over Zr-Mont possessing both Lewis and Bronsted acid sites. In an integrated dehydration + Claisen-Schmidt condensation sequence, Zr-Mont catalyst was filtered off and the crude HMF with MIBK underwent Claisen-Schmidt condensation over CaMgAl(231) catalyst. The overall 32% yield of Claisen-Schmidt condensation product was achieved from glucose. MIBK acting also as a product extractant, could be recovered upto 80%.

10aClaisen-Schmidt condensation10adehydration10aintegrated10ajet-fuel precursor10arenewable1 aShinde, Suhas1 aTarade, Komal1 aMitra, Gaurav1 aRode, Chandrashekhar uhttps://library.ncl.res.in/content/integration-heterogeneous-acid-and-base-catalysis-clean-synthesis-jet-fuel-precursor01997nas a2200229 4500008004100000022001400041245012500055210006900180260000800249300001100257490000800268520118700276653001901463653001801482653003301500653002401533653001701557100001801574700001801592700002501610856013201635 2020 eng d a0378-382000aMagnetically separable catalyst for condensation of renewable aldehydes and 2-methylfuran to saturated cyclic oxygenates0 aMagnetically separable catalyst for condensation of renewable al cJAN a1061910 v1973 a

The saturated cyclic ethers produced from biomass derived aldehydes and 2-methylfuran are the potential diesel fuel candidates. The synthesis of saturated cyclic ethers is a two step process which involves acid catalyzed condensation of aldehydes with 2-methylfuran and the subsequent selective furan ring hydrogenation of the condensation products. Here, we designed a novel recyclable magnetic solid acid catalyst such as [Fe3O4@SiO2-Pr-Py-H][2HSO(4)(2-)] and employed for the condensation of 2-methylfuran with formaldehyde as model substrates and reaction parameters were optimized. Under the set reaction conditions, condensation of 2-methylfuran with several other aldehydes were also successfully achieved with very good yields. Further, several supported noble metal catalysts were screened in order to find suitable catalyst system for selective furan ring hydrogenation of condensation products. Among those, 5% Pd/C was found to be very active and selective for furan ring hydrogenation without formation of ring opened products under very low hydrogen pressure at room temperature. Prepared catalysts were thoroughly characterized with sophisticated techniques.

10afuel additives10aHydrogenation10aHydroxyalkylation-alkylation10aMagnetic solid acid10aOrganosilica1 aTarade, Komal1 aShinde, Suhas1 aRode, Chandrashekhar uhttps://library.ncl.res.in/content/magnetically-separable-catalyst-condensation-renewable-aldehydes-and-2-methylfuran-saturated02604nas a2200169 4500008004100000022001400041245008600055210007000141260000800211300001400219490000700233520201800240100001802258700002502276700001902301856011402320 2025 eng d a1144-054600aMagnetically separable Brønsted acid catalyst for the synthesis of Bisguaiacol-F0 aMagnetically separable Brønsted acid catalyst for the synthesis  cFEB a3273-32840 v493 a

Currently, polycarbonates, epoxy resins, and plastics are commercially made from Bisphenol-A. However, BPA-containing materials are well known for causing major health problems and have been banned in several countries. To address this concern, Bisguaiacol-F (BGF) has been developed as a safer and more sustainable alternative to Bisphenol-A. We created a novel sulfonic acid-functionalized, magnetically separable heterogeneous Br & oslash;nsted acid catalyst, [Fe3O4@SiO2-(Pr)3-N-Bu-SO3H][HSO4-], which was successfully utilized for the manufacture of BGF by condensing 37% aq. formaldehyde with two molecules of guaiacol. The main objective for this reaction was to avoid using excess guaiacol while also completing the conversion of both starting components. Surprisingly, our manufactured catalyst promotes the complete conversion of aqueous formaldehyde and guaiacol into regioisomers such as pp `-BGF, mp `-BGF and op `-BGF with 62%, 15%, and 6% selectivity, respectively. Our novel magnetically separable heterogeneous catalyst has improved catalytic activity in terms of starting material conversion and product distribution, which can be attributed to its unique structural characteristics. It contains a pendant -SO3H group that is connected to a lengthy butyl chain, making it conveniently accessible in the reaction. We have created the framework for a promising and environmentally aware approach to the synthesis of Bisguaiacol-F by meticulously optimizing reaction parameters such as time, temperature, reactant molar ratio, and catalyst loading. The catalyst was extensively characterized using acid-base titration, FT-IR, XRD, TGA, and NMR techniques to confirm the structure and reveal remarkable stability and activity. Notably, the catalyst demonstrated recyclability across six consecutive runs, with no noticeable reduction in its effectiveness. The catalytic activity was also tested for guaiacol condensation with a variety of aldehydes to create Bisguaiacol derivatives.

1 aTarade, Komal1 aRode, Chandrashekhar1 aKamble, Sanjay uhttps://library.ncl.res.in/content/magnetically-separable-br%C3%B8nsted-acid-catalyst-synthesis-bisguaiacol-f