Iranian Journal of Catalysis
Volume:13 Issue: 4, Autumn 2023

This review papers aims to comprehensively address the various aspects of ionic liquids and supported ionic liquids, which constitute a significant branch within the expansive field of green catalyst. Specifically, it delves into the recent advancements made in this domain over the past three years for the synthesis of heterocyclic compounds. In the introduction section of this review, the discussion revolves around the structural diversity of ionic liquids with an acidic nature. Furthermore, the introduction presents a clear and definitive classification system for diverse types of acidic ionic liquids. In the last part of this review paper, a comprehensive literature review would be provided on the application of ionic liquids and supported ionic liquids for the synthesis of heterocyclic compounds. The primary objective of this review is to present a comprehensive perspective on the utilization of ionic liquid and supported ionic liquid in the synthesis of various heterocyclic compounds. Special attention is given to the pivotal role played by reusable supported ionic liquids in this process.

Chemical bath deposition (CBD) was used to prepare titanium dioxide (TiO2) nanocrystalline thin films on glass substrates. The TiO2 nanocrystalline thin films were created, and the Scanning Electron Microscope (SEM) images showed that they developed as nanoflowers and tiny semi-nanoplate bundles that grew vertically onto the surface of the substrates with uniform distribution. The nanoplate ranges in length from 26 to 149 nm and the average thickness was between 13 and 228 nm. The prepared TiO2 nanoflower thin films have an energy band gap of 3.26 eV, according to optical characteristics. Using various pH values and UV light exposure durations, the photocatalytic activity of the produced TiO2 nanoflower thin films was examined against the methylene blue (MB) dye at room temperature. When irradiation duration and pH were increased, the photodegradation rate of MB dye also increased. After 240 minutes of exposure, the photodegradation rate of MB dye with pH values of 6, 8, 9, 10, and 11 was 51%, 64%, 79%, and 82%, respectively. The kinetic rate constant for photocatalytic degradation of MB dye was determined to be 0.0069, 0.0061, 0.0038, and 0.0028 min-1 for pH values of 11, 9, 8, and 6, respectively.

The current research work was mainly focused on the antibacterial performance of Mn/Mg co-doped TiO2 nanoparticles in presence of Gemini surfactant (GS). Mn, Mg co-doped TiO2 nanoparticles were synthesized by sol-gel method and calcined at 450 0C. The characterization results reveal that among all the co-doped TiO2 and surfactant encapsulated TiO2 nanoparticles, the MMT5-GS2 Nano catalyst exhibited the most favorable properties, featuring a small particle size, a large surface area, with respective values of 6.6 nm, 230.2 m2/g, and a bandgap of 2.66 eV. The efficiency of the synthesized catalysts was examined by the antibacterial activity of Escherichia coli (E. coli) and Klebsiella pneumonia pathogens. Among all the catalysts, MMT5-GS2 demonstrated the best performance. The zone of inhibition of bacterial growth for E. coli and Klebsiella pneumonia was measured to be (33.1±0.12 mm) and (26.1±0.12 mm) respectively, at a concentration of 400 µg/mL. These values are significantly higher than the standard value of (chloramphenicol-16.71±0.2) at 100 µg/mL, indicating the remarkable efficacy of the MMT5-GS2 nanocatalyst. The co-doped nano titania particles encapsulated with surfactant have great potential as antibacterial agents.

The development of high-performance hydrotreating catalysts has been a challenging pursuit within the catalyst research field. In this study, activated carbon was synthesized chemically, utilizing oxygen gas as the activator and Merbau wood as the precursor. Subsequently, the activated carbon was impregnated with both mono (Ni, Pt, Pd) and bimetallic (NiPt) species. Physical activation employing oxygen gas was employed in the preparation of the activated carbon. Notably, the optimum activation temperature using oxygen gas was identified at 350°C, aligning with the peak iodine value of 3989.7 mg/g. Subsequently, the activated carbon served as a highly efficient support material for the hydrocracking of castor oil. Among the investigated catalysts, the NiPt/AC catalyst emerged as the most promising, achieving a remarkable liquid fraction conversion of 88.73 wt%. However, it is crucial to acknowledge that the NiPt/AC catalyst exhibited limitations in terms of stability, experiencing sintering and performance degradation after only three usage cycles.

A magnetic organic-inorganic hybrid of Fe3O4@SiO2-functionalized propylpiperazine-1,4-diium tungstate (A) nanoparticles with a spherical structure was prepared and completely characterized by XRD, SEM, TGA-DTA, and FT-IR spectral techniques. The magnetic hybrid was used in the oxidation of symmetrical sulfides to symmetrical sulfoxides under ambient conditions. The excellent yields of sulfoxides, easy operation, and recovery, magnetic properties of the catalyst, and environmentally friendly system are the key advantages of this method.

Synthesis of pyrano-pyrazol, pyrano-coumarin, and 4H-chromene derivatives has been achieved by the multicomponent reaction of substituted 1,3-diketo compounds, dialkyl acetylene dicarboxylates and alkyl nitrile derivatives in presence of nano-NiFe2O4. The nano-NiFe2O4 magnetic nanoparticle was prepared by a simple and effective method and characterized by using XRD, HRTEM images, IR, and VSM studies. The green, convenient, and mild protocol provided large access to desired products in almost quantitative yield. High catalytic activity, very low catalyst loading, and high recyclability are the attractive features of the developed protocol. All reactions were easily performed and preceded with high efficiency under very mild conditions avoiding time-consuming, costly catalysts, and tedious workup and purification of process.

Pyrimido[4,5-b]quinolones play a significant role in medicinal chemistry owing to their various biological properties, including antihistaminic, antimalarial, antifungal, anticancer, antioxidant, antiviral, anti-microbial, and anti-inflammatory activities. A dual acidic ionic liquid anchored on graphene oxide nanosheets (GO-Si-Pr-Lysin-SO3H) was provided and characterized using transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and Fourier transform infrared spectroscopy (FT-IR). The six-step process was utilized to create this catalyst, beginning with graphite powder. This catalyst was capable to develop the one-pot and three components (6-amino-1,3-dimethyluracil, dimedone, and different aromatic aldehydes) synthesis of pyrimido[4,5-b]quinolone derivatives at moderate temperature in water as a green medium (12 derivatives). The results obtained indicated that this method could be an effective approach for synthesizing pyrimido[4,5-b]quinolones with high yields ranging from 86% to 98% in a short reaction time of 15 to 40 minutes. In addition, the pointed catalyst shows reusability and recoverability without remarkable loss of catalytic activity.

Dr. Shripad Mukundrao Patil was born in Maharashtra, India on November 30, 1993. He received his B. Sc. degree in pure chemistry (2015) and M. Sc. in organic chemistry (2017) from Dada Patil Mahavidyalaya, Karjat-414401, Savitribai Phule Pune University, Pune, Maharashtra, India. He was also awarded his Ph.D. degree in organic chemistry (July 2023) under the guidance of Dr. Runjhun Tandon and Co-guidance Dr. Nitin Tandon, from the School of Chemical Engineering and Physical Science, Lovely Professional University, Phagwara-144411, Punjab, India. He published 16 international research papers in Scopus journal and one on international patent. He also attended three international conferences and two international workshops. His research interest is synthesizing and characterizing novel silica-coated magnetic nanoparticles and their applications in organic transformation. He also worked on the development of organic reactions using green methods.