The cycloaddition of pyridinium ylides with alkynes was investigated under mild conditions. A series of 13 pyridinium salts was prepared by alkylation of 4-substituted pyridines. Their reactivity with propiolic ester or amide in various reaction conditions (different temperatures, solvents, added bases) was studied, and 11 indolizines, with three points of structural variation, were, thus, isol...

The role of pyridinium cations in electrochemistry has been believed known for decades, and their radical forms have been proposed as key intermediates in modern photoelectrocatalytic CO(2) reduction processes. Using first-principles density functional theory and continuum solvation models, we have calculated acidity constants for pyridinium cations and their corresponding pyridinyl radicals, a...

Novel, double-chained pyridinium compounds have been developed that display highly efficient DNA transfection properties. The transfection efficiency of several of these compounds is enhanced by an order of magnitude, when compared with the transfection efficiency accomplished with the widely used cationic lipid system, lipofectin. Most importantly, the pyridinium compounds were found to be ess...

A validated ion chromatographic method was developed and applied for the determination of the maximum solubility of pyridinium ionic liquids in several aromatic solvents. Elution was performed on a Metrosep C3-150 prototype column at 40°C with acetonitrile-water at a flow rate of 1.0 mL min(-1). Mixtures of pyridinium ionic liquids and aromatic solvents were diluted with acetonitrile and aceton...

Key words nickel catalysis - deamination cross-coupling unnatural peptides amino acid pyridinium salts

The discovery, understanding and synthetic exploitation of the photochemical transformation of pyridinium salts are described. The investigations surrounding the remarkable transformation of pyridinium salts into a host of structurally complex motifs have helped extend the comprehension of aromatic and heteroaromatic photochemistry. The synthetic community has, in recent years, recognised the p...

In the title compound, (C(7)H(11)N(2))[Er(H(2)O)(8)]Cl(4)·H(2)O, the asymmetric unit consists of one 4-(dimethyl-amino)-pyridinium and one octa-aqua-erbium cation balanced by four Cl(-) anions, and one water mol-ecule. The 4-(dimethyl-amino)-pyridinium cation is protonated at the pyridine N atom. The dimethyl-amino group (C/N/C) lies close to the plane of the pyridinium ring, making a dihedral ...

Polysubstituted pyridinium salts are valuable pharmacophores found in many biologically active molecules. Their synthesis typically involves the use of multistep procedures or harsh reaction conditions. Here, we report water-based phosphate mediated reaction conditions that promote the condensation of arylacetaldehydes with amines to give 1,3,5-pyridinium salts. The reaction, carried out at pH ...