An amino acid bioconjugate of an organoplatinum tris(pyrazolyl)borate complex: Synthesis and structure of [p-(tBuO–Phe–CO)C6H4Tp]PtMe3

The platinum trimethyl complex of a benzoic acid-functionalized hydrido-tris(pyrazolyl)borate (Tp) ligand [p-(HO2C)C6H4Tp]PtMe34 has been synthesized from the corresponding p-bromo complex [p-BrC6H4Tp]PtMe33. Compound 4 may be readily coupled to biomolecules such as amino acids as exemplified by coupling to l-phenylalanine-tert-butylester to provide [p-(tBuO–Phe–CO)C6H4Tp]PtMe35. Compound 5 has been structurally characterized in the solid state by X-ray diffraction. It constitutes the first example of a tris(pyrazolyl)borate bioconjugate.