p-Toluenesulfonylmethyl isocyanide is a synthetic reagent used in the synthesis of triplet drugs with the 1,3,5-trioxazatriquinane skeleton, pyrroles, oxazoles and in imidazoles. It serves as an isonitrile component in a diastereoselective Passerini reaction. Furthermore, it is used in the Van Leusen reaction to convert aldehydes to nitriles.