The present disclosure relates to electrophilic reactive linkers, which find utility labeling target substrates according to the formula L1-El, El-L1, or L1-El-L2, wherein El is an electrophilic reactive group and wherein L1 and L2 are linking molecules. Molecules according to the present invention find use, for example, in multifunctional chimeric molecules (e.g., bifunctional molecules), which make substrate modifications such as post-translational modifications to targets that are not the natural substrate; accordingly, diseases or disorders may be treated or prevented with molecules of the present disclosure.