Current Organic Chemistry - Volume 15, Issue 9, 2011

Since the discovery of Pedersen that dibenzo[18]crown-6 complexed alkali metal ions in 1967, supramolecular chemistry has expanded quickly and evolved to an interdisciplinary science. Although early works focused on the development of various crown ethers for investigating their binding affinity towards metal ions and ammoniums, in early 1970s linear molecules as synthetic receptors had begun to attract the attention of Read More

Association units with high strength and specificity are getting increasing attention in the construction of well-defined selfassembling systems, which are making controlled non-covalent synthesis a reality. A class of hydrogen-bonded duplexes consisting of oligoamide strands carrying various combinations (sequences) of hydrogen-bond donors and acceptors has exhibited superb ability as intermolecular association units. Thes Read More

This review highlights the advances in molecular recognition based on the linear molecular receptors in the past decade. Three kinds of linear receptors that bind discrete neutral, cationic and anionic organic molecules, metal ions, and halide anions are described. The first are foldamer receptors that are induced by intramolecular non-covalent forces to spontaneously fold into compact conformations. The second are lin Read More

Aromatic oligoamide foldamers whose helical structures were stabilized by intramolecular hydrogen bindings between consecutive units not only can mimic the secondary or tertiary structures of its natural counterparts but also provide alternative approaches to study the properties of biopolymers in artificial systems. Aromatic oligoamide foldamers are sequence-specific oligomers as demonstrated in peptides and DNA Read More

Based on the discovery of hydrazide dimer supramolecular synthon, various supramolecular structures were successfully constructed. Attaching hydrazide unit into a quinolinone skeleton led to a new quadruply hydrogen bonding mode. With properly encoded hydrogen bonding sites the oligohydrazide strands self-assembled into duplex strands. Linear arrangement of two hydrazide units led to a new supramolecular zippe Read More

Perylene diimides (PDIs) have been playing important roles in several active fields. Therefore, we will first review the current methods to modify the skeleton of perylene diimides. Next, PDI self-assemblies and PDI folded nanostructures and chemically restrained PDI nanostructures are presented. Unusual physical properties due to nanostructures formation are discussed including the absorption band intensity reversal and π-stack Read More

Pyridinium ylids are versatile tools in organic synthesis. The stability of pyridinium ylids and their generation is commented. This review gives an overview of the possible modes through which pyridinium ylids can react. It is demonstrated that pyridinium ylids are suitable building blocks for the synthesis of indolizines, cyclopropanes, 2,3-dihydrofurans, 2(1H)-pyridin(ethio)ones, mono- & oligopyridines, pyranonaphthoquinones, nit Read More

The Meliaceae family is rich sources of limonoid (meliacin), which are well know for their antifeedant activity and bitterness. Although their existence also could be found in Rutaceae, Cneoraceae, Ptaeroxylaceae, and Simaroubaceae family, they are especially abundant and structurally diversified in the Meliaceae family. Structurally, they are highly oxygenated and modified nortriterpenoids either containing or derived fr Read More

Salt-Type Organic Acids (STOA) catalysts consisting of organic components and acidic sites, possessing salt characteristics simultaneously, have been paid much attention from the whole world as reaction promoters to acid-catalyzed reactions. In recent years, the replacement of the conventional mineral acids with environmentally benign ones has become one of the prime concerns of the chemists for the sake of the Read More

Pyrazoles are of considerable interest due to the broad variety of their biological activities. This overview summarizes structures of pharmacologically interesting pyrazoles, natural products, technically applied pyrazoles as well as pyrazole syntheses published during the last decade. In addition, new insights into the properties such as tautomerisms, conformations, pyrolyses and decomposition reactions of py Read More