Mini-Reviews in Organic Chemistry - Volume 7, Issue 2, 2010

This review is intended to cover the developments in the chemistry of poly(azolyl)borates through the years 2000-2008, based on the main synthetic methods, coordination properties, spectroscopic and structural features of this important class of ligands. The subject matter is the chemistry of substituted bis-, tris- and tetrakis-(pyrazolyl)borate ligands. In this review we provide essential information to allow the reader to probe more deeply into the main aspects of the chemistry of these fascinating and flexible ligands. This review would also demonstrate the enormous potential of poly(pyrazolyl)borates chemistry, as also the future perspectives in this field.

Synthetic iron chelators (siderophores mimics) are of paramount interest as clinical iron removal agents (iron overload is one of the most common poisoning) and water-soluble iron complexes can be used to alleviate iron deficiency in plants. Moreover, some additional properties may be needed for a precise function (as examples, probes for studying metal transport, diagnostic tools, agent suited for vectorisation…). We describe in this review the organic syntheses of selected typical examples from our own works. (i) Amphiphilic chelators based on catechol groups. (ii) Mixed ligands based on catechol and quinoline groups. (iii) Quinolobactin, a natural siderophore. (iv) Oxinobactin, a biomimetic synthetic analog of enterobactin involving 8-hydroxyquinoline chelating subunits.

Polycyclic aromatic hydrocarbons (PAHs), regarded as a class of hazardous pollutants due to their persistence and toxicity, are ubiquitous in the environment. Much research has been conducted on aerobic microbial degradation of some PAHs and determination of the degradation pathways for which synthesis of metabolic intermediates and metabolites is required. This mini-review briefly summarizes synthesis of commercially unavailable metabolites of phenanthrene, anthracene, pyrene, fluoranthene, and benzo[a]pyrene.

Organic compounds have long been considered the most natural representatives of the insulating state. It started to change about fifty years ago, after the synthesis of an extraordinary organic molecule: tetracyano-p-quinodimethane (TCNQ). This molecule displays unique chemical and physical properties and give rise to a very rich class of organic conducting materials. The common feature of this conductors is high ordering of TCNQ molecules, very often in linear one-dimensional chains or columns. The physical properties of TCNQ salts are determined by two major points: 1) a restricted electronic dimensionality and 2) electronic correlations and electronphonon interactions. The aim of the paper is to review the influence of the properties and spatial structure of the cations on selected physical properties of adequate TCNQ complex salts. Some uncommon effects such as thin layer's molecular organization and anions orientation, multidimensionality of hydrogen bonded networks of the salts - their types and strengths, melting of organic composites based on TCNQ and photoinduced melting of spin-Peierls phase in CT compounds are discussed. Possible applications of TCNQ salts are also mentioned.

The genus Valeriana (Valerianaceae) contains over 250 species distributed around the world and used in traditional medicines of many cultures. The main compounds isolated from Valeriana species are essential oils, valerenic acid and its derivatives and iridoids, accumulated mainly in the roots and rhizomes. This review lists 135 chemical constituents as well as their biosynthesis and bioactivity as reported by the end of 2008 (80 references).