@article {44147, title = {Cascade reductive etherification of bioderived aldehydes over Zr-based catalysts}, journal = {ChemSusChem}, volume = {10}, year = {2017}, month = {OCT}, pages = {4090-4101}, type = {Article}, abstract = {An efficient one-pot catalytic cascade sequence has been developed for the production of value-added ethers from bioderived aldehydes. Etherification of 5-(hydroxymethyl)furfural with different aliphatic alcohols over acidic Zr-montmorillonite (Zr-Mont) catalyst produced a mixture of 5-(alkoxymethyl)furfural and 2-(dialkoxymethyl)-5-(alkoxymethyl)furan. The latter was selectively converted back into 5-(alkoxymethyl)furfural by treating it with water over the same catalyst. The synthesis of 2,5-bis(alkoxymethyl)furan was achieved through a cascade sequence involving etherification, transfer hydrogenation, and re-etherification over a combination of acidic Zr-Mont and the charge-transfer hydrogenation catalyst [ZrO(OH)(2)]. This catalyst combination was further explored for the cascade conversion of 2-furfuraldehyde into 2-(alkoxymethyl)furan. The scope of this strategy was then extended for the reductive etherification of lignin-derived arylaldehydes to obtain the respective benzyl ethers in >80\% yield. Additionally, the mixture of Zr-Mont and ZrO(OH)(2) does not undergo mutual destruction, which was proved by recycling experiments and XRD analysis. Both the catalysts were thoroughly characterized using BET, temperature-programmed desorption of NH3 and CO2, pyridine-FTIR, XRD, inductively coupled plasma optical emission spectroscopy, and X-ray photoelectron spectroscopy techniques.}, doi = {10.1002/cssc.201701275}, author = {Shinde, Suhas and Rode, Chandrashekhar} } @article {44638, title = {Cascade synthesis of 5-(Acetoxymethyl) furfural from carbohydrates over Sn-mont catalyst}, journal = {ChemistrySelect}, volume = {3}, year = {2018}, month = {AUG}, pages = {8770-8778}, abstract = {

The 5-(Acetoxymethyl)furfural (AcMF) is emerged as an important alternative for 5-(hydroxymethyl)furfural (HMF). It is also a starting material for those products which are typically prepared from HMF. The growing importance of AcMF encouraged us to prepare it directly from cheap and abundant carbohydrates. The production AcMF from glucose and glucose-like carbohydrates is an exigent assignment, owing to tough isomerisation of glucose to fructose. The Sn-Mont catalyst having a unique combination of Lewis as well as Bronsted acid sites was employed for direct glucose conversion into AcMF. Lewis acid sites of Sn-Mont facilitate the isomerisation of glucose to fructose. At the same time, dehydrative-esterification of fructose to AcMF is catalyzed by Bronsted acid sites of Sn-Mont. Different concentrations of Sn containing Sn-Mont catalysts were by prepared mixing montmorillonite clay with different molar concentration (e.g. 0.1 M-0.4 M) of aqueous solutions of SnCl4 center dot 5H(2)O. AcMF was produced in as high as 43\% yield directly from glucose over Sn-Mont(0.3 M) catalyst owing to its highest acid strength. The efficacy of Sn-Mont(0.3 M) catalyst was also probed for sucrose and fructose that resulted in 53\% and 58\% yield of AcMF, respectively. The critical properties of all the prepared Sn-Mont catalysts were investigated through XRD, BET surface area, ICP-OES, temperature-programmed desorption of NH3 and pyridine-FTIR and XPS techniques.

}, keywords = {5-(Acetoxymethyl)furfural, Bronsted/Lewis acid, carbohydrates, Dehydrative-esterification, Sn-Mont}, issn = {2365-6549}, doi = {10.1002/slct.201802040}, author = {Shinde, Suhas and Deval, Kashmira and Chikate, Rajeev and Rode, Chandrashekhar} } @article {44478, title = {Friedel{\textendash}crafts alkylation over Zr-mont catalyst for the production of diesel fuel precursors}, journal = {ACS Omega}, volume = {3}, year = {2018}, month = {MAY}, pages = {5491{\textendash}5501}, type = {Article}, abstract = {Heterogeneous Zr-Mont catalyst prepared by a simple protocol was employed for the production of diesel fuel precursors via Friedel{\textendash}Crafts (FC) alkylation of petroleum-derived arenes (e.g., mesitylene, xylene, and toluene) with biomass-derived 5-(hydroxymethyl)furfural (HMF), HMF derivatives, and carbohydrates. Initially, several acidic catalysts were screened for the FC alkylation of mesitylene with HMF in nitroethane solvent. Among all, Zr-Mont catalyst gave an exceptionally high yield (80\%) of mesitylmethylfurfural (MMF). The catalytic activity of Zr-Mont was also evaluated for the alkylation of different petroleum-derived arenes with ester/halogen derivatives of HMF. Suitable acid strength and high surface area of Zr-Mont were its major attributes to make it the most efficient solid acid catalyst for this FC reaction. Even after several reuses, the catalytic activity of Zr-Mont was found to be consistent, which was also evidenced by the acidity measurements of fresh and reused Zr-Mont catalysts by temperature-programmed desorption of ammonia and pyridine Fourier transform infrared spectroscopy techniques. Direct conversion of glucose to diesel fuel precursors was also attempted over Zr-Mont catalyst in mesitylene and polar nonacidic solvents at 150 {\textdegree}C. However, the activity of Zr-Mont catalyst was limited for glucose dehydration to HMF and MMF did not form. When the same experiment was performed in formic acid medium, MMF was produced in 34\% yield. After the addition of formic acid, the reaction becomes biphasic which contains mesitylene as an organic phase and formic acid as an aqueous phase. Formic acid worked as a solvent, reactant, and cocatalyst, whereas mesitylene worked as a reactant and product extraction phase to enable easy product isolation. With this strategy, other diesel fuel precursors were also produced in 26{\textendash}30\% yields from glucose and different arenes. Similar strategy was successfully extended for the conversion of sucrose to diesel fuel precursors.}, doi = {10.1021/acsomega.8b00560}, author = {Shinde, Suhas and Rode, Chandrashekhar Vasant} } @article {46020, title = {Pyridine immobilised on magnetic silica as an efficient solid base catalyst for Knoevenagel condensation of furfural with acetyl acetone}, journal = {Catalysis Communications}, volume = {124}, year = {2019}, month = {MAY }, pages = {81-85}, type = {Article}, abstract = {

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.

}, keywords = {furfural, Jet fuel, Knoevenagel condensation, Silica immobilised pyridine, Solid base}, issn = {1566-7367}, doi = {10.1016/j.catcom.2019.03.005}, author = {Tarade, Komal and Shinde, Suhas and Sakate, Sachin and Rode, Chandrashekhar} } @article {46243, title = {Two-step sequence of acetalization and hydrogenation for synthesis of diesel fuel additives from furfural and diols.}, journal = {Energy \& Fuels}, volume = {33}, year = {2019}, month = {AUG}, pages = {7466-7472}, type = {Article}, abstract = {

Acetalization of diols with furfural and subsequent hydrogenation of acetal products provided potential fuel additives that could be blended into commercial diesel. Glycerol could be an interesting polyol for acetalization with furfural due to its low cost, and it is produced as a byproduct in very large amount in the process of biodiesel production. In this work, glycerol acetalization with furfural has been selected as a model reaction. Acetalization reaction was performed under neat conditions (solventless) with 1:1 molar ratio of furfural and glycerol at room temperature over various acid catalysts, including homogeneous and heterogeneous acids. Among several catalysts, Zr-Mont, a heterogeneous solid acid having controlled acidity, gave as high as 78\% isolated yield of acetal products. Interestingly, acetal products can be isolated in pure form by performing extraction using cyclohexane that enables selective extraction of product, and unreacted glycerol and furfural were left in aqueous phase, which can be recycled. Further, to make fuel components from isolated acetal product of glycerol and furfural, hydrogenation was performed over a series of supported noble-metal catalysts under low H-2 pressure at room temperature. Among them, 5\% Pd/C showed very high activity for ring hydrogenation that resulted in high yield of hydrogenation products. However, hydrogenated product contains free hydroxyl group that needs to be subsequently etherified or acetylated. Interestingly, etherified derivative was obtained in high yield compared to acetylated derivative. In addition, several other diols were treated with furfural and their products were subsequently hydrogenated over 5\% Pd/C under very low H-2 pressure. The properties of resulting compounds were investigated so as to find most suitable candidates as additives to commercial diesel.

}, doi = {10.1021/acs.energyfuels.9b01640}, author = {Patil, Anil and Shinde, Suhas and Kamble, Sanjay and Rode, Chandrashekhar, V} } @article {47002, title = {Integration of heterogeneous acid and base catalysis for clean synthesis of jet-fuel precursor from carbohydrates}, journal = {ChemistrySelect}, volume = {5}, year = {2020}, month = {JAN }, pages = {392-400}, type = {Article}, abstract = {

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\%.

}, keywords = {Claisen-Schmidt condensation, dehydration, integrated, jet-fuel precursor, renewable}, issn = {2365-6549}, doi = {10.1002/slct.201903735}, author = {Shinde, Suhas and Tarade, Komal and Mitra, Gaurav and Rode, Chandrashekhar} } @article {47027, title = {Magnetically separable catalyst for condensation of renewable aldehydes and 2-methylfuran to saturated cyclic oxygenates}, journal = {Fuel Processing Technology}, volume = {197}, year = {2020}, month = {JAN}, pages = {106191}, type = {Article}, abstract = {

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.

}, keywords = {fuel additives, Hydrogenation, Hydroxyalkylation-alkylation, Magnetic solid acid, Organosilica}, issn = {0378-3820}, doi = {10.1016/j.fuproc.2019.106191}, author = {Tarade, Komal and Shinde, Suhas and Rode, Chandrashekhar} } @article {47641, title = {Role of preparation parameters of Cu-Zn mixed oxide catalyst in solvent free glycerol carbonylation with urea}, journal = {Journal of the Indian Chemical Society}, volume = {98}, year = {2021}, month = {JUL}, pages = {100090}, type = {Article}, abstract = {Solvent-free carbonylation of glycerol with urea to glycerol carbonate (GC) was achieved over heterogeneous Cu-Zn mixed oxide catalyst. Cu-Zn catalysts with different ratios of Cu:Zn were prepared using co-precipitation (CP) and oxalate gel (OG) methods. As compared to CuO-ZnO(2:1) catalyst prepared by oxalate gel (OG) method, much higher conversion of glycerol and highest selectivity towards glycerol carbonate (GC) was achieved with CuO-ZnO_CP(2:1) catalyst. Physicochemical properties of prepared catalysts were investigated by using XRD, FT-IR, BET, TPD of CO2 and NH3 and TEM techniques. The effect of stoichiometric ratio of Cu/Zn, calcination temperature of CuO-ZnO catalysts and effect of reaction parameters such as molar ratio of substrates, time and temperature on glycerol conversion to GC were critically studied. Cu/Zn of 2:1 ratio, glycerol-urea 1:1 molar ratio, 145 degrees C reaction temperatures were found to be optimized reaction conditions to achieve highest glycerol conversion of 86\% and complete selectivity towards GC. The continuous expel of NH 3 from reaction the mixture avoided formation of ammonia complex with CuO-ZnO catalyst. As a result of this, CuO-ZnO catalyst could be recycled up to three times without losing its initial activity.}, keywords = {Co-precipitation (CP), Glycerol, Glycerol carbonate, Oxalate gel (OG)}, issn = {0019-4522}, doi = {10.1016/j.jics.2021.100090}, author = {Charate, Shrinivas and Shinde, Suhas and Kondawar, Sharda and Desai, Uday and Wadgaonkar, Prakash and Rode, Chandrashekhar} }