Efficient formation of water- and air-stable aza-ylides has been achieved using the Staudinger reaction between electron-deficient aromatic azides such as 2,6-dichlorophenyl azide and triarylphosphines. The reaction proceeds rapidly and has been successfully applied to chemical modification of proteins in living cells.

An efficient preparation method of functionalized phosphines by copper-catalyzed azide–alkyne cycloaddition (CuAAC) through the transient protection of phosphine from the Staudinger reaction is disclosed. Diverse phosphines were prepared from phosphinyl...