Question

Why would use of a chemoselective method be beneficial over a less selective reaction that modifies common amino acids (e.g., lysine)?

Answer 1

The structure of lysine is shown as above. It has two -NH₂ groups and one -COOH group as functional groups. Reactions with chemoselectivity is the preferential reaction of a chemical reagent with one of two or more different functional groups. As there are two amine functional groups present in the lysine: one at the terminal (position a) and the other connected with the alpha-carbon (position b), chemoselective reaction is more effective for selective modification of lysine's any of the -NH₂ group.