Kevin R. Gerzevske

A novel approach to the synthesis of symmetrical and unsymmetrical porphyrin dimers

Abstract Methodology for synthesis of symmetrical or unsymmetrical porphyrin dimers linked at the meso positions with phenyl or stilbene functionalities is reported; 5-porphyrinyl-dipyrromethanes are key intermediates in this approach.

Kinetic vs Thermodynamic Product Distributions of Macrocyclic Tetrapyrrole Cyclization Products from 1,19-Disubstituted A,C-Biladiene Salts

Chromium(III) promoted oxidative cyclization reactions of a,c-biladiene hydrobromides bearing bulky 1- and 19-substituents to give macrocyclic products are partially reversible; depending upon the reaction temperature, kinetic or thermodynamic products are formed and identified

New syntheses of biliverdins, corroles and azaporphyrins from 1,19-dibromo-ac-biladiene salts

Treatment of the readily available, 1,19 dibromo-ac-biladiene dihydrobromide salts 3 with dimethyl sulfoxide (DMSO) in presence of a catalytic amount of toluene-p-sulfonic acid affords symmetrical and unsymmetrical biliverdins 4 in excellent yield; unsymmetrically substituted 1,19 dibromo-ac-biladiene dihydrobromide 3c was prepared in a stepwise fashion via a tripyrrin salt. Under appropriate reaction conditions, the ac-biladiene dihydrobromides were also converted in modest yields into the corroles 5 and the azaporphyrins 6.

Stepwise synthesis of 1,19-dibromo-a,c-biladienes and their conversion into biliverdins, corroles and azaporphyrins

The first stepwise syntheses of unsymmetrically substituted 1,19-dibromo-a,c-biladienes, e.g.3c, via the so-called ‘tripyrrene route’, and their facile conversion into biliverdins (bilin-1,19-diones), e.g.4c, are described; this methodology is also adapted for the preparation of symmetrical biliverdins 4a, as well as corroles 5 and azaporphyrins 6.