Staudinger Ligation: A Peptide from a Thioester and Azide

Abstract
The technique of native chemical ligation enables the total chemical synthesis of proteins. This method is limited, however, by an absolute requirement for a cysteine residue at the ligation juncture. Here, this restriction is overcome with a new chemical ligation method in which a phosphinobenzenethiol is used to link a thioester and azide. The product is an amide with no residual atoms.