Mild mannered: Unprotected amides and sulfonamides containing aryl bromides and iodides undergo, in the presence of S‐PHOS, smooth Negishi cross‐couplings with various zinc organometallic reagents, allowing the preparation of pharmaceutically relevant molecules (see scheme; S‐PHOS=2‐dicyclohexylphosphino‐2′,6′‐dimethoxybiphenyl).
A remarkably simple method for the synthesis of di- and trisubstituted functionalised oxazoles under metal- and catalyst-free conditions is described. An iterative bromination and debromination of N-acylated amino acid derivatives with NBS as the sole reagent cleanly led to various substituted oxazoles.