Vinylazides: versatile synthons and magical precursors for the construction of N-heterocycles.

Nowadays, application of vinylazides as precursors is a key method for the construction of N-heterocycles in organic synthesis. These versatile three-atom synthons can be converted into intermediates such as 2H-azirines, iminyl radicals, iminyl metal complexes, iminyl inions and nitrilium ions that subsequently afford a wide range of polyfunctional cyclic nitrogen-containing compounds. In this review, the reactions of vinylazides leading to these products (in the last decade) are categorized based on the types of the resulting N-heterocyclic rings and a brief and concise description of the reaction mechanisms is presented.

Synthesis and pharmacological properties of polysubstituted 2-amino-4H-pyran-3-carbonitrile derivatives.

2-Amino-3-cyano-4H-chromenes are structural core motifs that received increasing attention in the last years due to their interesting potential pharmacological properties. In this review, the synthetic methods for these compounds are classified based on the type of catalyst in the pertinent reactions. In addition, the wide range of pharmacological properties of these compounds is covered in a separate section.

Intramolecular Click Cycloaddition Reactions: Synthesis of 1,2,3-Triazoles.

Click Chemistry, as a powerful tool, has been used for the synthesis of a variety of 1,2,3-triazoles. Among click cycloaddition reactions, intramolecular click reactions carried out in azido-alkyne precursors has not been thoroughly reviewed. Hence, in this review, we have summarized and categorised the recent literature (from 2012 on) based on the azidoalkynyl precursor's type and a brief and concise description of the involved mechanisms is presented. Accordingly, we have classified the relevant literature into three categories: (1) substitution precursors (2) addition and (3) multi-component reaction (MCR) products.