Recent advances in organic synthesis applying elemental selenium

The synthesis of organoselenium compounds through C–Se bond-forming has attracted immense attention due to their biological values and extensive pharmaceutical applications. As a result, diverse selenating reagents have been developed over the past few decades for this purpose. In particular, elemental selenium (Se), with the advantages of being non-toxic, odorless and chemically stable, has gained numerous interests as it showed great potentials for the formation of variously valuable organoseleniums via direct incorporation of Se atom into target molecules in a simple way. Moreover, direct C–H bond selenation with elemental Se has been considered as a highly atom-economic method to C–Se bond formation because it avoided substrate pre-activation. In view of the importance of organoselenium compounds, this review highlights the recent advances in organic synthesis involving elemental Se since 2002, which would be useful for researchers in the learning of Se for organic reactions.