Phosphorus pentoxide for amide and peptide bond formation with minimal by-products

Phosphorus pentoxide and DMAP are used for amide bond formation from carboxylic acids and amines. Dipeptides and amides have been synthesized using this reagent in 42–77% yields and >99% ees. The protocol is attractive as it occurs at ambient temperature, the formation of organic by-products is minimal and the reagent can be readily quenched using water. Furthermore, excellent enantioselectivities are observed without the use of harsh triazole based additives.