Current Organic Chemistry - Volume 23, Issue 21, 2019

Heterocyclic chemistry is the only branch of chemistry that has applications in varied areas such as dyes, photosensitizers, coordination compounds, polymeric materials, biological, and many other fields. Quinoline and its derivatives have always engrossed both synthetic chemists and biologists because of their diverse chemical and pharmacological properties as these ring systems can be easily found in various natural products, especially in alkaloids. Among alkaloids, quinoline derivatives i.e. quinolinium salts have attracted much attention nowadays owing to their diverse biological profile such as antimicrobial, antitumor, antifungal, hypotensive, anti-HIV, analgesics and anti-inflammatory, etc. Quinoline and its analogs have recently been examined for their modes of function in the inhibition of tyrosine kinases, proteasome, tubulin polymerization, topoisomerase, and DNA repair. These observations have been guiding scientists for the expansion of new quinoline derivatives with improved and varied biological activities. Quinolinium salts have immense possibilities and scope to investigate these compounds as potential drug candidates. Therefore, we shall present a concise compilation of this work to aid in present knowledge and to help researchers explore an interesting quinoline class having medicinal potential.

Most of the synthetic chemical transformation reactions involve the use of different organic solvents. Unfortunately, some of these toxic solvents are used in chemical laboratory, industry and have been considered a very serious problem for the health, safety of workers and environmental damage through pollution. The purpose of green chemistry is to provide a path that reduces or eliminates the use of such hazardous toxic solvents. Therefore, the key factor of the green synthetic approach is to utilize renewable materials, nontoxic chemical and to perform the reactions under solvent-free conditions. In this review, we have discussed most recent literature survey on applications of solvent-free techniques in organic synthesis which would offer a new opportunity to a researcher to overcome the problem of using environmental harmful solvents.

The triazole and sulfonamide compounds are known as biologically active agents that were employed for medicinal applications. These compounds were obtained in different forms by a variety of techniques to vast ranges of applications. The broad biological properties of these compounds have encouraged researchers to design and synthesize triazole-based sulfonamide derivatives as compounds with potential biological activity. In this review, we summarized the synthetic procedures of triazole-based sulfonamide compounds together with their biological activities during the last two decades.

Pakistan is experiencing the worst power shortage since 2007 ranging from 5000 to 7000 MW. This has led to introduction of load shedding program which has caused economic loss @7% to the GDP. The indigenous oil reserves are poor and every year crude oil and petroleum products costing US$ 15.473 billion are imported. The potential of biomass energy is excellent, and Pakistan may generate 38000 GWh electricity annually using 25% crops residue and 50% animal waste. Except for Punjab province survey of crops biomass needs to be conducted to estimate the biomass resource potential in the country. Based upon the data, the size of power plants can be determined, and site of plants can be decided. Very few power plants have been installed by local industry under captive mode and their experience is encouraging. The indigenous capacity building for installation and operation of bio-mass based power plants are required. This paper reviews the power shortage and its implications on economy of Pakistan. It also describes the biomass technologies, resource base and power generation potential along with utilization status in Pakistan. It also discusses possible role of biomass power in mitigating the energy crisis especially in the rural areas. Using only 20-25% of the estimated crops waste of major crops and 50% of animal’s waste Pakistan can generate more than 36,000 GWh equivalent to 45% of the electricity consumption per annum. The crops residue alone can produce 11953 MW (31%) of the power potential with 25% of the available crops residue.

The particular β-cyclodextrin 3D structure, with its hydrophilic surface and apolar cavity, has enabled to partially or totally encapsulate hydrophobic molecules of appropriated size and shape in aqueous solution as well as in solid-state through the formation of a reversible host–guest complex. Accordingly, β-cyclodextrin based nanosponges have been prepared and used in previous years for the synthesis of organic compounds. In this review, we are going to mention some of the recent reports on the application of β- cyclodextrin 3D nanosponges in organic synthesis catalysis. Furthermore, it should be mentioned that these compounds have also been utilized for numerous applications including drug delivery, gas storage, rubber manufacture, diagnostics, cosmetics, agriculture, smart fabrics, water purification, and flame retardants.