One-pot synthesis of nickel porphyrins with 2-pyridine-acetyl substituents: the unexpected Sonogashira cross-coupling products

Nickel porphyrins with 2-pyridine-acetyl substituents were synthesized in one step by the Sonogashira cross-coupling method. The structures of the products were determined by elemental analysis, 1H NMR, UV–Vis, and X-ray spectroscopic techniques. It is suggested that cross-coupling bromonated nickel porphyrins with 2-pyridine-ethyne first yielded nickel porphyrins with 2-pyridine-ethynyl substituents, followed by in situ hydrolysis to the final products, nickel porphyrins with 2-pyridine-acetyl substituents.