01938nas a2200145 4500008004100000245008500041210006900126260000800195300001400203490000700217520140800224100001801632700002501650856011701675 2017 eng d00aCascade reductive etherification of bioderived aldehydes over Zr-based catalysts0 aCascade reductive etherification of bioderived aldehydes over Zr cOCT a4090-41010 v103 aAn 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.1 aShinde, Suhas1 aRode, Chandrashekhar uhttps://library.ncl.res.in/content/cascade-reductive-etherification-bioderived-aldehydes-over-zr-based-catalysts02278nas a2200241 4500008004100000022001400041245009300055210006900148260000800217300001400225490000600239520147500245653003001720653002401750653001801774653003101792653001201823100001801835700002001853700002001873700002501893856011801918 2018 eng d a2365-654900aCascade synthesis of 5-(Acetoxymethyl) furfural from carbohydrates over Sn-mont catalyst0 aCascade synthesis of 5Acetoxymethyl furfural from carbohydrates  cAUG a8770-87780 v33 a

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.

10a5-(Acetoxymethyl)furfural10aBronsted/Lewis acid10acarbohydrates10aDehydrative-esterification10aSn-Mont1 aShinde, Suhas1 aDeval, Kashmira1 aChikate, Rajeev1 aRode, Chandrashekhar uhttps://library.ncl.res.in/content/cascade-synthesis-5-acetoxymethyl-furfural-carbohydrates-over-sn-mont-catalyst02005nas a2200157 4500008004100000245008700041210006900128260000800197490000800205520143000213100002401643700002101667700002101688700002501709856011301734 2019 eng d00aCrystalline LaCoO3 perovskite as a novel catalyst for glycerol transesterification0 aCrystalline LaCoO3 perovskite as a novel catalyst for glycerol t cOCT0 v4753 a

LaCoO3 perovskite was synthesized using sol-gel method by nitrate and acetate precursors of La and Co with varying molar ratios of La and Co (1:1, 1:2 and 2:1). This was found to be an unique strategy to obtain highly crystalline LaCoO3 perovskite material without using any chelating agent. The variation of precursors was found to influence their crystallinity however, variation in molar ratio in the range of 0.5-2, did not affect the formation of perovskite framework. The formation of pure perovskite phase (around or > 80%) could be achieved by combination of acetate and nitrate precursors while, the combination of acetate- acetate or nitrate- nitrate precursors resulted in low phase purity for the perovskite due to the formation of secondary phases like La2O3 and Co3O4. Very interestingly, such combination of perovskite and pure oxide phases contributed to enhancement of basic sites which catalyzed the glycerol transestrifiaction with DMC (dimethyl carbonate) to GC (glycerol carbonate) and GD (glycidol). Among all the catalysts studied, NAP-2 showed highest efficiency in terms of 98% glycerol conversion and 77% GC and 22% GD selectivities. The highlight of this work is that first step glycerol transesterification with DMC required basic sites of either metal oxide or perovskite but for cascade reaction involving decarboxylation required both metal oxide as well as LaCoO3 perovskite phase.

1 aPhadtare, Deepshree1 aKondawar, Sharda1 aAthawale, Anjali1 aRode, Chandrashekhar uhttps://library.ncl.res.in/content/crystalline-lacoo3-perovskite-novel-catalyst-glycerol-transesterification04129nas a2200169 4500008004100000245013600041210006900177260000800246300001200254490000700266520348100273100001703754700001903771700001703790700002503807856012703832 2024 eng d00aCalcination temperature impacting the structure and activity of CuAl catalyst in aqueous glycerol hydrogenolysis to 1,2-propanediol0 aCalcination temperature impacting the structure and activity of  cNOV a318-3310 v683 a

This study investigated the impact of calcination temperature on the structural properties of CuAl catalyst which was found to be a robust nano-structured catalyst calcined directly without ramping at 400 °C and performed exceedingly well for aqueous phase hydrogenolysis of glycerol. Various samples of CuAl catalysts were prepared by co-precipitation at Cu: Al molar ratio 1:1 and were calcined at different temperatures (300–1000 °C). The obtained catalysts were reduced at 200 °C before their activity testing for glycerol hydrogenolysis reaction. To correlate the structure-activity, the catalysts were thoroughly characterized by XRD, XPS, BET, TEM, H2-TPR, NH3-TPD, and pyridine FTIR. It was observed that with an increase in calcination temperature from 300 to 700 °C, the glycerol conversion also increased from 47 to 55% with 93% selectivity to 1,2-PDO. The better performance of these catalysts was mainly related to the predominant presence of Brønsted acid sites, an appropriate ratio of the Cu0 to CuAl2O4 + CuO (0.33) and CuAl2O4 to CuO phases (0.35), the existence of Cu2O phase and the smaller Cu0 particle size. It was shown that altering the ramping rate for the calcination temperature of 400 °C impacted the catalytic activity. The CuAl-400 (DC) (direct calcined) catalyst exhibited a maximum glycerol conversion of 60%.

1 aMane, Rasika1 aPotdar, Aparna1 aJeon, Yukwon1 aRode, Chandrashekhar uhttps://library.ncl.res.in/content/calcination-temperature-impacting-structure-and-activity-cual-catalyst-aqueous-glycerol02394nas a2200241 4500008004100000022001400041245012500055210006900180260000800249490000900257520156100266653002801827653002101855653001601876653001501892653002001907100001701927700002101944700001901965700002501984700001902009856012402028 2024 eng d a0022-328X00aCuNPs@Al2O3-cellulose composite for the ligand-free Suzuki cross-coupling reactions in batch and continuous flow process0 aCuNPsAl2O3cellulose composite for the ligandfree Suzuki crosscou cJAN0 v10043 a

In the present work, we synthesized recyclable CuNPs@Al2O3-CELL composite from an inexpensive and commercially available synthetic reagent by a simple method. The catalyst was characterized by various techniques such as TGA (Thermogravimetric analysis), SEM (Scanning electron microscope), TEM (Transmission electron microscopy), XPS (X-ray photoelectron spectroscopy), EDS (Energy dispersive spectroscopy), and AAS (Atomic Absorption Spectroscopy). The composite was applied for the Suzuki coupling reactions in the batch and flow process. The aryl halides were easily coupled with arylboronic acids in 95 % ethanol at 78 C. We systematically investigated the role of reaction temperature, solvent, and catalyst loading, on the transient and steady-state behavior of the flow reactor through an automated flow chemistry platform. The CuNPs@Al2O3CELL catalytic particles demonstrate minimal deactivation and leaching over a continuous Suzuki coupling reaction at a 20 min nominal residence time at 100 C. Moreover, the catalyst can be recovered by simple filtration and reused at least five times with a moderate decrease in product yield. The excellent activity and stability of the catalyst have been attributed to the strong chelation of the Cu species with hydroxyl functional groups of the Al2O3-CELL composite. The catalytic system was highly efficient in Suzuki coupling of various aryl bromides with different aryl boronic acids, yielding good to excellent product yields (80-96 %) with a TON of 15.914-19.066 and TOF of 2.649-9.533 h(-1).

10aContinuous flow process10aCuNPs@Al2O3-CELL10aligand-free10arecyclable10aSuzuki coupling1 aPatil, Seema1 aRajmane, Archana1 aJadhav, Sanjay1 aRode, Chandrashekhar1 aKumbhar, Arjun uhttps://library.ncl.res.in/content/cunpsal2o3-cellulose-composite-ligand-free-suzuki-cross-coupling-reactions-batch-and