We report a robust and sustainable approach for the selective N-formylation of API and their intermediates containing primary or secondary amine (both aliphatic and aromatic) in the presence of DMF and catalytic AcOH under microwave irradiation. The optimized conditions were established via N-formylation of Lopinavir intermediate-I and various marketed drugs (e.g. Duloxetine, Atomoxetine, Nebivolol, Desloratadine, Valaciclovir, Phenylephrine, Memantine, Vortioxetine, Tamsulosin, Palbociclib and Crizotinib) were employed subsequently. The other substrates include multi-functionalized API intermediates possessing various substituents or groups in addition to chiral centers in some cases. Generally, the N-formylation proceeded smoothly affording the corresponding product in good to acceptable yield. All the reactions were performed in gram scale and the methodology does not require the use of expensive and cumbersome column chromatographic purification of products. The selectivity, eco-friendly nature, low cost, operational and isolation/purification simplicity along with the access to several valuable drug impurities are the key features of the current protocol. When tested for anti-bacterial activities in vitro against several S. aureus strains along with E. coli, the low to good inhibition was noted for compound 2d and 2e against S. aureus.

Sol gel auto-combustion was used to create gadolinium doped nickel ferrite nano-particles, which have chemical composition NiFe2‑xGdxO4 (x = 0.00, 0.010, 0.15, 0.20 & 0.25). The investigation focused on how the composition of Gd+3 affected the magnetic properties and structural parameters. Magnetic properties were investigated using VSM technique, structural properties were determined using XRD and SEM techniques. XRD graphs verified the establishment of the spinel ferrite phase. With an increase in Gd composition, the crystallite size and lattice parameter increased from 21.0288 to 27.04125 nm and 8.3325 to 8.3367Å, respectively. It was also evident how the composition of Gd+3 affected the estimation of bond-angles and lengths in tetrahedral and octahedral structures. SEM micrographs showed that all of the grains had a small amount of agglomeration and that all of the synthesized compositions were homogenous. The range of 140.5–176.2 nm was found to be the average grain size. Using VSM at 300K, magnetic parameters like coercivity, residual magnetization, and saturation magnetization were computed. Until the composition was 0.20, the saturation magnetization and residual magnetization dropped from 30.28 emu/g to 15.35 emu/g and 5.07 emu/g to 3.65 emu/g, respectively. After that, they increased to 34.40 emu/g and 6.52 emu/g, respectively. Until composition 0.20, coercivity was raised from 154 to 261 Oe; after that, it was lowered to 233 Oe.

The gadolinium-doped nickel ferrites with the chemical composition of NiFe2−xGdxO4 (0.00 £ x £ 0.25) ferrites were synthesized by sol–gel auto-combustion. Spinel ferrite phase formation was analyzed using XRD analysis. The dielectric constant, loss tangent, and the AC conductivity were investigated. The dielectric properties with Gd doping content were studied from 100 Hz to 1 MHz frequency range from room temperature to 400 °C. These results were very well in agreement with Maxwell–Wagner interfacial polarization. The dielectric properties were observed to depend on the frequency and the Gd doping concentration. According to Koop theory, spinel ferrites exhibit a beneficial trend whereby their dielectric constant drops as frequency increases. This behavior is supported by the various cationic distributions within the spinel structure. The use of these materials in medium-frequency devices is reflected in the largest magnitude of the tangent loss at low frequencies. Thus, projected spinel nanoferrites could be advantageous for microwave and sophisticated electronics devices.

In the present work, gadolinium-doped nickel ferrite nanoparticles with the chemical composition NiFe2−xGdxO4 (X = 0.00, 0.05, 0.10, 0.15, 0.20, and 0.25) have been prepared by the sol-gel auto-combustion method and calcinated at 700 ∘C. The spinel ferrite phase formation was confirmed with the XRD graphs. In all the samples, the typical absorbance peak was observed in between 250–300 nm. Tauc plots were used to calculate the optical energy band gap, found in the range of 4.033–4.144 eV, and it was also calculated using x-ray density to be in the range of 3.690–4.300 eV. Both of them were observed in good agreement with each other, and we conclude that the Gd composition could finely tune the optical energy band gap. The impact of Gd composition was clearly observed on optical parameters. The refractive index, reflectivity, absorption coefficient, optical dielectric constant, and dielectric susceptibility have shown the increasing tendency from 2.1140 to 2.2325, 12.80 to 14.53%, 5.4380 to 6.3032 cm−1, 3.4690 to 3.9840 and 0.2760 to 0.3170, respectively, whereas the transmission coefficient decreased from 0.7730 to 0.7461.

An easy and efficient large-scale synthesis of 1, 2,-di-O-acetyl-5-O-benzoyl-3-O-methyl-d-ribofuranose (8) was accomplished from commercial 1,2:5,6-di-O-isopropylidene-α-d-allofuranose in 7-steps and 30 % overall yield. The utility of protected 8 was demonstrated via synthesis of 9-(3'-O-methyl-β-d-ribofuranosyl)-6-chloropurine (21) and six other nucleoside analogues in good yields. A library of five novel base modified nucleosides were generated starting from purine nucleoside 21 via functional group manipulations. The 3'-O-modified nucleosides are known to act as chain terminator exerting antiviral activity. The synthesis strategy described herein offers direct access to 3'-O-alkylated nucleosides with wide range of applications, including cap analogues for mRNA vaccine production. This protocol provides a route to exclusive synthesis of 3'-O-alkylated nucleosides, devoid of isomeric 2'-O-alkylated products essential for both therapeutic and biological research.

A simple and efficient protocol is developed for regioselective protection of primary hydroxyl group of nucleosides using 2,7-dimethylpixyliumtrifluoroacetate, prepared in-situ from 2,7-dimethyl-9-phenylxanthen-9-ol (DMPx-OH) and trifluoroacetic anhydride (TFAA). Furthermore deprotection of DMPx group is accomplished with TFAA in shorter reaction times with excellent yields in DCM:Methanol solvent system. Both procedures are successfully implemented on gram scale for synthesis of natural as well as other modified nucleosides. Various functional groups such as benzoyl, benzyl, tetrahydropyranyl, TBDPS, and formamidine groups are intact during protection with DMPx-group.

Abstract Regio/chemo-selective hydrolysis of a 5,6-O-isopropylidene group over a 1,2-O-isopropylidene group is accomplished to obtain corresponding diols in good to excellent yields within 4–5 hours using the p-toluenesulfonic acid impregnated MCM-41 (PTSA-MCM-41) catalyst in acetonitrile and water (9:1, v/v) at room temperature. Other sensitive hydroxyl protecting groups such as naphthyl, toluoyl, pivaloyl, benzoyl, and benzyl are compatible with this methodology. The low cost of the PTSA-MCM-41 catalyst and ease of separation of product from the reaction mixture are significant advantages of this method, which makes it useful in the multigram scale operation. Graphical Abstract

Cobalt-silica nanocomposite catalysts have been prepared using sol–gel process followed by drying under different conditions. The use of amino functionalized silane in the gelation step provided homogeneous distribution of the cobalt through the whole material. TEM, XPS and H2-TPR data reveal that highly dispersed cobalt(II) sites are present in the samples. The catalysts were evaluated for selective aerobic epoxidation of olefins without the use of sacrificial reductant. Among the Co-SiO2 nanocomposite catalysts, aerogel prepared catalyst has shown superior activity due to the high porosity clubbed with highly accessible cobalt(II) sites.

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Selective transfer hydrogenation of aromatic ketones and beta-keto esters to the corresponding alcohols was achieved by using ruthenium nanoclusters supported on alkali-exchanged zeolite beta catalyst. The high activity and selectivity of the catalyst is due to the presence of highly dispersed ruthenium clusters in combination with the large number of Bronsted acidic sites of zeolite.

An improved process for the oxidation of toluene to obtain benzaldehyde and benzyl alcohol with high selectivities using a Co/Mn/Br − composite catalytic system in liquid phase is described. A protocol for recovery and reuse of the composite catalyst is developed. The use of low concentrations of composite catalytic systems aimed at minimizing corrosion of the reaction, and higher concentrations of toluene affording higher productivity and recyclability of the catalyst giving high turnover number, are the remarkable achievements of the present methodology. Investigation into the recycle, aging and spectroscopic studies of the catalytic system improves the understanding of the process, chemistry and mechanism of the reaction. As the market demand for each product fluctuates, the dynamic system developed here to meet changing demands is very important to obtain one of the products in excess quantities with a change of the ratio of Br − /Cl − .