Mini-Reviews in Organic Chemistry - Volume 16, Issue 5, 2019

Ball-type phthalocyanines are recently synthesized binuclear derivatives of the widely known phthalocyanine molecule. In the ball-type Pc molecule, two cofacially arranged Pc rings have four bridged substituents on the peripheral positions of benzenes. Due to their cofacially arranged phthalocyanine rings and, strong intramolecular and intermolecular interactions, ball-type phthalocyanines have different properties than their parent molecule and these structures have many potential application areas. This review describes three different synthesis methods of ball-type phthalocyanines; synthesis in the solvent, synthesis in solid, and synthesis under microwave irradiation. The synthesis that occurs in the shortest time with the highest yield is the synthesis in the solid phase. General differences between a ball-type phthalocyanine and a monophthalocyanine, such as differences in electronic spectra and effects of cofacial arrangement and central metal atoms, are also discussed. The shape of the Q-bands indicates the differences in electronic spectra. In ball-type Pcs, the Q-bands are broad and have poor resolution. Some potential applications, such as gas sensors, NLO devices, potential usage in photodynamic therapy and artificial photosynthesis of ball-type phthalocyanines are also mentioned. Ball-type Pcs can be used as a sensor for gases such as; CO2, CO, SO2, VOC. A novel water-soluble ball-type Pc may have potential application in PDT. Finally, we consider future prospects of these molecules.

Furans are five-membered aromatic heterocycles containing one oxygen atom that are important building blocks in organic chemistry, but also as natural products found in various natural sources, mostly in plants, algae and microorganisms. In this review, we discussed recent advances in the synthesis of furan compounds. Some classical methods have been modified and improved, while other new methods have been developed. A vast variety of catalysts was used for these transformations. In many studies, furan synthesis reaction mechanisms were also investigated and proposed.

Direct substitution and elimination reactions of the fluorine atoms of difluoromethylene CF2α groups of nonspaced perfluoroalkyl chains, CF3 groups are very difficult to achieve. But, they become feasible with fluoro-alkenes, alkynes, imines or carbonyl derivatives, for which vinylic substitution and related carbanion-mediated pathways are available. In this review, we classify the major and unique fluorine substitution/elimination and rearrangement reactions and discuss their contribution to the synthesis of heterocyclic compounds.

Medicinal properties of papaya (Carica papaya Linn.) fruit and other parts are wellknown in the traditional system of medicine. Papaya plant originated in Central America and now grown in tropical areas of worldwide, most particularly in Africa and Asia. Studies validate that, papaya has several pharmacological activities, such as antioxidant, antiulcer, antibacterial, woundhealing, anti-inflammatory and anti-sickling, just to name a few. The present review article provides the explicit and updated information on botanical aspects, ethnomedicinal uses, phytochemistry and pharmacological activities of C. papaya plant in order to explore their therapeutic potential. This review conducted a systematic search on C. papaya through electronic database search (Google Scholar, PubMed, SciFinder, Scopus, Science Direct, and Web of Science) and a library search for articles published in peer-reviewed journals, until January of 2018. Constituents of papaya plant belongs to different chemical classes that include alkaloids, flavonoids, terpenoids, saponins, steroids, tannin, vitamins, quinones, minerals and others. Experimental evidence confirmed that these classes of compounds cure the microbial infections, diabetes, inflammatory, cytotoxic and liver disorders. Conclusively, the present review aimed to summarize the information of ethnomedicinal uses, phytochemistry and pharmacological activities to prevent and treat the wide range of diseases and disorders. The future research draws the attention of the researcher for intensive investigations relating to phytochemicals, pharmacological activities and industrial applications.

Ultrasonic irradiation is employed to accelerate organic reactions. Under sonication reduced time, good selectivity, excellent yield, and milder conditions were observed for many organic reactions. Ultrasonic reactions are increasingly used as green, clean, and environment-friendly methods in organic synthesis in terms of energy conservation and waste minimization. The use of ultrasound irradiation is increasing in coming years. The use of ultrasound irradiation in the synthesis of five-membered N-heterocycles is depicted in the present review article.