STEPWISE SYNTHESES OF UNSYMMETRICAL TETRA-ARYLPORPHYRINS - ADAPTATION OF THE MACDONALD DIPYRROLE SELF-CONDENSATION METHODOLOGY

A new synthetic route to meso-tetraarylporphyrins [e.g. (12,13)] using a MacDonald-type 2+2 condensation is established. The method presented here shows wide applicability for the preparation of 5,10,15,20-tetra-arylsubstituted porphyrins with two-fold rotational symmetry. The 2+2 method is further extended to give a tetraarylporphyrin (14) bearing four different aryl groups in a predesignated array. © 1990.