Selective Pd0‐Mediated CC Bond Constructions on the Imidazole Ring of L ‐Histidine: A Practical Approach to the Synthesis of Diphthamide and Related Histidine Analogues

A simple access to histidines that contain a carbon branch at the C2 atom of the imidazole ring is provided by reaction (a). The protected monoiodo histidine 1 is therefore a versatile coupling partner.