Mini-Reviews in Organic Chemistry - Volume 16, Issue 2, 2019

Alumina (Aluminium Oxide, Al2O3), a white odorless solid powder is an inexpensive and widely used inorganic material which is insoluble in water and organic solvents. It may also be called aloxide, aloxite, or alundum. Nano forms of this inorganic metal oxide could be seen in different crystalline polymorphic phases for alumina, such as α-Al2O3, β-Al2O3, γ-Al2O3, δ-Al2O3, θ-Al2O3, η-Al2O3, Κ-Al2O3, χ-Al2O3, and ρ-Al2O3. Generally, the nano size of alumina showed better activity due to its common form because of the vast surface area which led to larger surface-to-volume ratio. Alumina is a versatile substance in many compounds which possess interesting utility in biology, industry, and drugs. Nano alumina have been utilized in different branches of industry, medicine, and biology. It could play key role in abrasives, ceramics, and dental composites, electronic, absorbent, nano-carriers for delivery of anticancer, and surgical implants. Besides, it possesses particular position, as a heterogeneous Lewis acid catalyst or catalyst support in chemistry. Due to interesting properties of nano alumina in this report we focused on its catalytic activity in organic transformations. The review subdivided with centralization on reactions that progressed with sole nano alumina and the reactions which improved by nano alumina support catalysts. In is noteworthy that although many reactions have been reported by alumina catalytic role, the ones which underwent by nano-size aluminum oxides are few. This fact denote that this substance is a potent-catalyst system in future organic chemistry domain. The review describes the various organic reactions promoted by nano alumina catalysts relevant up to 2017.

The development of benzoxazole containing drugs and research compounds has been discussed in the present review along with its varied pharmacological activities such as antimicrobial, antiinflammatory, anticancer, antiviral, antiasthmatic, antitubercular, anticonvulsant, lipid modulating, anticoagulants, antidiabetic and anthelmintic activities. The present review is a compilation of the biological activities determined in the research work conducted on benzoxazole-based compounds fused and linked with various other heterocycles.

The beginning of 1970's may well be regarded as turning point in the area of organic synthesis when an efficient and straight forward strategy for the reaction of primary and/or secondary alcohols with variety of nucleophiles in the presence of triphenylphosphine and azodicarboxylate reagent was discovered by O. Mitsunobu and since then rapid progress has been made in understanding and applying the Mitsunobu reaction for various derivatization reactions. Due to versatile applications and mild reaction conditions associated with the said strategy, the Mitsunobu reaction has received much attention in the last almost fifty years and has been well reported. The basic objective of this review is to pay attention on the recent advances and applications of the Mitsunobu reaction particularly in last decade. The attention has also been paid to describe various modifications which have been explored in the traditional Mitsunobu reaction by substituting P (III) reagents or azodicarboxylate reagents with other suitable reagents or else using an organocatalyst with the objective to improve upon the traditional Mitsunobu reaction. In the present review we wish to report the major advancements achieved in last few years which are likely to be beneficial for the researchers across the globe.

Cancer is considered one of the globally top lethal and never-ending public health troubles which affects the humankind population that mainly suffers from bone marrow tumor, breast cancer and lung cancer. Many health professionals and scientists have developed conventional therapies with a number of different modules of medicines obtainable from drugstores to cure diversified cancer disease despite the fact that none of these drugs have been found to be fully effective and safe. So, there is a great potential for the study of medicinal plants to reveal powerful anticancer activities. This coherent review is focused on an extensive investigation of frequently incited therapies through naturally occurring medicinal plants that cover a large number of pharmacological anticancer activities. During recent years, research has been focused on the structural modifications to accomplish anticancer medicines, drugs and complex physical therapies. Nevertheless, all reported therapies crafted improvements in the quality of cancer patients' life issues however; these efforts are required to be escalated at a large scale and in high level clinical trials. The review covers the literature from 1985-2016.

Graphene-based materials with their astonishing properties including exceptional thermal and electrical conductivity, strong mechanical characteristics, as well as antibacterial characteristics have many promising applications in industry and medicine. Graphene-based materials have been utilized in different fields of medicine such as thermal therapy, drug delivery and cancer therapy. In addition, the prevalence of bacterial multidrug resistance has attracted worldwide attention. Therefore, there is a growing tendency to use nanomaterials, especially graphene family to overcome this problem. To date, no specific mechanism for antibacterial activity of graphene-family has been reported. This review briefly discusses the physiochemical properties of graphene nanomaterials with a focus on the different antibacterial mechanisms, surface engineering and nanosheets size to provide a better insight for further research and development.

Polycyclic structures fused at a central carbon are of great interest due to their appealing conformational features and their structural implications in biological systems. Although progress in the development of synthetic methodologies towards such structures has been impressive, the stereoselective construction of such quaternary stereocentres remains a significant challenge in the total synthesis of natural products. This review summarises a series of studies on the reactions of 1H-pyrrole-2,3- diones with nucleophiles and highlights the progress in the formation of new polyheterocyclic compounds with concomitant formation of the quaternary spiro centre.

4-Formylpyrazoles are useful building blocks in organic synthesis. This review focuses on the applications of 4-formylpyrazoles to generate a large variety of organic compounds and heterocycles such as Schiff bases, pyrazolylpyrazolines, pyrazoloquinolinones, 4H-pyrazolopyran, pyrazolylbenzoxazole, pyrazolothiadiazepines, pyrazolyloxazolone, pyrazolyloxadiazolines, pyrazolylthiadiazolines, imidazolylpyrazoles, pyrazolopyridines, chromenopyrazolones, thiopyranothiazolylpyrazoles and many others. Many of these molecules exhibit excellent biological activities.