Of interest in chemical biology is the Staudinger ligation, which has been called one of the most important bioconjugation methods.  Two versions of the Staudinger ligation have been developed.  Both begin with the classic iminophosphorane reaction.  
In classical Staudinger ligation, the organophosphorus compound becomes incorporated into the peptide.   Typically, appended to the organophosphorus component are reporter groups such as fluorophores. In traceless Staudinger ligation, the organophosphorus group dissociates giving a phosphorus-free bioconjugate.