Synthesis of trans-A2B2-porphyrins bearing phenylethynyl substituents.

Efficient and convenient conditions for the preparation of trans-A(2)B(2)-porphyrins bearing two phenylethynyl moieties directly from phenylpropargyl aldehydes and dipyrromethanes of diversified lipophilicity and reactivity have been developed. This new procedure allows the preparation of a library of porphyrins of this architecture with a wide range of substituents. Thanks to the identification of the reagent solubility as one of the key factors influencing the yield of the porphyrinogens, we were able to improve yields to ca.