In recent years microwave (MW) assisted synthesis has been used in the synthesis of mesotetraarylporphyrins.
In fact during the last fifteen years new and important results on the
application of MW irradiation on the porphyrin synthesis and funcionalization have appeared.
It has been demonstrated that, by using this type of irradiation, not only porphyrins but also
their metal complexes can be synthesized.7
Also in this case, the acid catalysis is essential for
the success of such syntheses. For example, 5,10,15,20-meso-tetraphenylporphyrin (TTP) has
been efficiently prepared by condensation of pyrrol and benzaldehyde, in the presence of
propionic acid as catalyst and under MW irradiation (Scheme 6)