Chitosan-based nanofibrous scaffolds for biomedical and pharmaceutical applications: A comprehensive review.

Nowadays, there is a wide range of deficiencies in treatment of diseases. These limitations are correlated with the inefficient ability of current modalities in the prognosis, diagnosis, and treatment of diseases. Therefore, there is a fundamental need for the development of novel approaches to overcome the mentioned restrictions. Chitosan (CS) nanoparticles, with remarkable physicochemical and mechanical properties, are FDA-approved biomaterials with potential biomedical aspects, like serum stability, biocompatibility, biodegradability, mucoadhesivity, non-immunogenicity, anti-inflammatory, desirable pharmacokinetics and pharmacodynamics, etc. CS-based materials are mentioned as ideal bioactive materials for fabricating nanofibrous scaffolds. Sustained and controlled drug release and in situ gelation are other potential advantages of these scaffolds. This review highlights the latest advances in the fabrication of innovative CS-based nanofibrous scaffolds as potential bioactive materials in regenerative medicine and drug delivery systems, with an outlook on their future applications.

Recent progress in reductive carboxylation of C-O bonds with CO2.

Transformation of carbon dioxide (CO2) into value-added organic compounds has attracted increasing interest of scientific community in the last few decades, not only because CO2 is the primary greenhouse gas that drives global climate change and ocean acidification, but also because it has been regarded as a plentiful, nontoxic, nonflammable and renewable one-carbon (C1) feedstock. Among the various CO2-conversion processes, carboxylation reactions represent one of the most beautiful and attractive research topics in the field, since it offers the possibility for the construction of synthetically and biologically important carboxylic acids from various easily accessible (pseudo)halides, organosilicon, and organoboron compounds. The purpose of this review is to summarize the available literature on deoxygenative carboxylation of alcohols and their derivatives utilizing CO2 as a carboxylative reagent. Depending on the C-O compounds employed, the paper is divided into five major sections. The direct dehydroxylative carboxylation of free alcohols is discussed first. This is followed by reductive carboxylation of carboxylates, triflates, and tosylates. In the final section, the only reported example on catalytic carboxylation of fluorosulfates will be covered. Notably, special attention has been paid on the mechanistic aspects of the reactions that may provide new insights into catalyst improvement and development, which currently mainly relies on the use of transition metal catalysts.

Reductive coupling of nitro compounds with boronic acid derivatives: an overview.

The purpose of this review is to summarize the current literature on reductive C-N coupling of nitro compounds and boronic acids, with special emphasis on the mechanistic features of the reactions. The metal-catalyzed reactions are discussed first. This is followed by electro-synthesis and organophosphorus-catalyzed reactions. Finally, the available examples of catalyst-free reactions will be covered at the end of this review.

Hydrazinosulfonylation of aryl electrophiles: a straightforward approach for the synthesis of aryl N-aminosulfonamides.

In recent years, the direct hydrazinosulfonylation of aryl electrophiles with SO2 and hydrazines has emerged as an efficient and versatile method for the synthesis of aryl N-aminosulfonamides. This method has the advantages of being operationally simple and requiring only readily available starting materials. This review article is an attempt to survey literature describing the preparation of aryl N-aminosulfonamides through the direct hydrazinosulfonylation of aryl electrophiles with SO2 and hydrazines, with special attention paid to the mechanistic features of the reactions. It can be used as a guide for chemists to apply the best hydrazinosulfonylation conditions in their work or serve as inspiration for future research related to the topic.

Using the aluminum decorated graphitic-C3N4 quantum dote (QD) as a sensor, sorbent, and photocatalyst for artificial photosynthesis; a DFT study.

In this project, we have investigated the possibility of mimicking the natural photosynthesis, as well as sensing and adsorption application of aluminum decorated graphitic C3N4 (Al-g-C3N4) QDs (toward some air pollutants containing CO, CO2, and SO2). The results of the potential energy surface (PES) studies show that in all three adsorption processes, the energy changes are negative (-10.70 kcal mol-1, -16.81 kcal mol-1, and -79.97 kcal mol-1 for CO, CO2, and SO2 gasses, respectively). Thus, all of the adsorption processes (mainly SO2) are spontaneous. Moreover, the frontier molecular orbital (FMO) investigations indicate that the Al-g-C3N4 QD could be used as a suitable semiconductor sensor for detection of CO, and CO2 (as carbon oxides) in one hand, and SO2 gaseous species on the other hand. Finally, the results reveal that those QDs could be applied for artificial photosynthesis (in presence of CO2; Δµh-e = 1.43 V), and for water splitting process for the H2 generation (Δµh-e = 1.23 V) as a clean fuel for near future.