Elemental Selenium in the Synthesis of Selenaheterocycles

An overview of the known methods introducing selenium under action elemental into structures various saturated, unsaturated, and heteroaromatic selenacycles containing C–Se, N–Se, B–Se, Ge–Se P–Se bonds is presented. These include metal, iodine, bromine or chlorine exchange for direct cyclization 1-(2-bromoaryl)benzimidazoles, polyunsaturated hydrocarbons, acetylenes, propargylic amines, 3-halogenaryl amides, aryl diazo-compounds, 2-aminoacetophenone, annulation ethynyl arenes. Three- four-component reactions utilizing as one components leading to selenium-containing heterocycles are presented well.