Current Organic Chemistry - Volume 20, Issue 9, 2016

In carbon dioxide utilization by cyclometalated five-membered ring products, the following compounds are used in four types of applications: 1. 2-Phenylpyrazole iridium compounds, pincer phosphine iridium compounds and 2-phenylimidazoline iridium compounds are used as catalysts for both formic acid production from CO2 and H2, and hydrogen production from the formic acid. This formic acid can be a useful agent for H2 production and storage for fuel cell electric vehicles. 2. Other chemicals, e.g., dimethyl carbonate, methane, methanol and CO, are produced with dimethylaminomethylphenyltin compounds, pincer phosphine iridium compounds, pincer phosphine nickel compound and ruthenium carbene compound or 2-phenylpyridine iridium compounds, and phenylbenzothiazole iridium compounds as the catalysts for the reactions with CO2. 3. The five-membered ring intermediates of cyclometalation reactions with the conventional substrates react with carbon dioxide to afford their many types of carboxylic acid derivatives. 4. Carbon dioxide is easily immobilized at room temperature with immobilizing agents such as pincer phosphine nickel compounds, pincer phosphine palladium compounds, pincer N,N-dimethylaminomethyltin compounds and tris(2-pyridylthio)methane zinc compounds.

Aryl halomethyl sulfones are halogenated organosulfur compounds which continuously draw attention owing to their bioactivity as well as wide applications in organic synthesis. This review summarizes the methods for their preparation, describing the reported routes to fluoro, chloro, bromo and iodo derivatives. Their synthetic and biological applications are also highlighted.

The studies performed during the last ten years on the possibility to determine an aromaticity criterion based on the energy of the occupied πorbitals has been described. The evolution of the research studies to obtain the D criterion defined as {[π1+ Σn2(π1-πn)]0/[π1+ Σn2(π1- πn)]} xa was described. The correlations between D and some other common aromaticity criteria have been presented showing a good relationship between D and other aromatic criteria; D values were used to determine some limits of other aromatic criteria. The role of both DFT functionals and basis sets have been discussed.

With the robust development of carbon material science, carbon nanotubes (CNTs) possessing novel chemical properties, unique high surface area and outstanding thermal and electronic properties have gained a special interest in membrane applications. The preparation of novel carbon nanotube (CNT) films and CNT hybrid membranes is still of great importance because of the new demands for membrane materials that have defined architectures and improved properties. Due to the high surface area, excellent electron conductivity, superhydrophobicity and enhanced mechanical strength of CNT films, the research on CNT films has blossomed during the recent decades. Many potential applications of CNT films in environment, energy, membrane transportation, electronic devices, and biosensors have been explored and implemented. In this review, we give a summary of the main aspects of CNT films related to its preparation, characterization and applications.

Sesquiterpenoids, consist of 15 carbons backbone, may play a highly significant role in natural products. There are various types of the sesquiterpenoids due to different spatial configurations via modification and rearrangement. Sesquiterpenoids exhibit various biological activities: anti-tumor, anti-viral, anti-microbial, anti-inflammatory and so on. The study on sesquiterpenes may receive more and more attentions, and will increase the chance to discover bio-active drug leads with medicinal potential. The present paper reviews the latest progress in the structural diversity and the biological activity of the new sesquiterpenes isolated from natural resource in recent years. Overall, 337 compounds, and 201 references are presented.