Iodine(III)-Based Hypervalent Iodine Electrophiles in Organic Synthesis

The chemistry of hypervalent iodine reagents is now developed as an important tool of synthetic organic chemistry. These reagents play a key role in replacing the toxic heavy metal reagent because of their mild reaction condition and environmentally friendly nature. Mainly, these reagents were known for oxidative properties, but the scope of these reagents is not limited to oxidation reactions. In the past two decades, they have been used as versatile electrophiles in various key organic transformations. Recently, the demand for these reagents has increased drastically for green chemistry, mainly due to their application in catalysis. Hypervalent iodine reagents have been successfully used to develop various oxidative transformations such as the oxidation of different organic species, α-functionalization of carbonyl compounds, cyclization reactions, C-H activation reactions, lactonization and oxidative rearrangements. Moreover, the use of these reagents is not limited to general organic reactions but is successfully used to develop several stereoselective transformations by using chiral hypervalent iodine reagents. This review article highlights various acyclic and cyclic reactions where the hypervalent iodine reagents have been used as electrophiles.