New Developments with Chiral Electrophilic Selenium Reagents

This review describes the development of enantiomerically pure selenium reagents as electrophiles in stereoselective synthesis. It outlines the addition of selenium electrophiles to alkenes, which can be used as part of key reactions in various transformations. Different nucleophiles can be employed in the addition reactions including oxygen, nitrogen and carbon nucleophiles. Furthermore, it has been shown that selenocyclisations can been performed using similar nucleophiles for the formation of different heterocycles. It has been established that the structure of the selenium electrophile, its counterion and the solvent all influence the course of these reactions. Most transformations use stoichiometric amounts of selenium containing reagents. Recently, selenenylation - deselenenylation reactions were discovered where only catalytic amounts of reagents are necessary.