The present application relates to a compound having a formula 1: B—R1-R2-M wherein B is a binding element for recognizing and binding a target; R1 is a first group of atoms for reacting with a functionality of the target so as to form a covalent bond with the target; R2 is a second group of atoms; R1 and R2 being such that the formation of the covalent bond between R1 and the target generates cleavage of the bond between R1 and R2 so as to free R2-M; and M is selected from the group consisting of a hydrogen atom and a pharmaceutically acceptable moiety. Alternatively, R1 and R2 can be inverted to form the formula II: B—R2-R1-M and being such that the formation of the covalent bond between R1 and the target generates cleavage of the bond between R1 and R2 so as to free R2-B.