Catalytic Acceptorless Dehydrogenation (CAD) of Secondary Benzylic Alcohols into Value-Added Ketones Using Pd(II)-NHC Complexes.

For the creation of adaptable carbonyl compounds in organic synthesis, the oxidation of alcohols is a crucial step. As a sustainable alternative to the harmful traditional oxidation processes, transition-metal catalysts have recently attracted a lot of interest in acceptorless dehydrogenation reactions of alcohols. Here, using well-defined, air-stable palladium(II)-NHC catalysts (A-F), we demonstrate an effective method for the catalytic acceptorless dehydrogenation (CAD) reaction of secondary benzylic alcohols to produce the corresponding ketones and molecular hydrogen (H2). Catalytic acceptorless dehydrogenation (CAD) has been successfully used to convert a variety of alcohols, including electron-rich/electron-poor aromatic secondary alcohols, heteroaromatic secondary alcohols, and aliphatic cyclic alcohols, into their corresponding value-added ketones while only releasing molecular hydrogen as a byproduct.

Extraction and characterization of natural lignocellulosic fibres from Typha angustata grass.

In recent years, efforts have been made to reduce deforestation to conserve the ecosystem. In the current scenario, agro-cultivated products are used instead of wood for engineering applications. Thus, natural lignocellulosic fibres are used as a reinforcing material and have been extremely attractive to industries and the scientific community during the past few decades. This study aimed to examine the use of natural fibres extracted from Typha angustata grass as reinforcement in polymer matrix composites. The density of the fibres was 1.015 g/cc. Chemical analysis confirmed that T. angustata fibres (TAFs) have a cellulose content of 73.54 wt%, a hemicellulose content of 10.11 wt%, a lignin content of 6.23 wt% and a wax content of 0.23 wt%. The crystallinity index (65.16 %) and crystalline size (6.40 nm) were identified by X-ray diffraction (XRD) analysis. The presence of functional groups in the TAFs was examined by employing Fourier-transform infrared spectroscopy (FTIR). The presence of cellulose at peak intensities of C2, C3 and C5 in the TAFs was confirmed using 13C nuclear magnetic resonance (NMR) spectroscopy. The single fibre tensile test revealed that the tensile strength was 665 ± 7 MPa and Young's modulus was 27.45 ± 3.46 GPa. The thermal stability of the TAFs was examined by thermogravimetric analysis (TGA), and the prominent peak was observed at 298.48 °C, with a kinetic activation energy of 67.99 kJ/mol. The surface roughness of the fibres was analysed by atomic force microscopy (AFM) with an accuracy of 1 nm. The above-mentioned outcomes indicated that the TAFs have desirable properties that are comparable to existing natural fibres and suggested to be utilised as the possible reinforcement to fabricate the fibre-reinforced polymer matrix composites.