Porphyrin Complexes with Highly Electronegative Metals - A New Chapter in Nucleophilic Substitution of Hydrogen?

Author(s): Stanisław Ostrowski, Sylwia Ostrysz, Agnieszka Mikus

The attempts of direct substitution of hydrogen in porphyrin macrocyclic systems, with carbanions of weak nucleophilicity, are described. Porphyrins, when converted into the corresponding metal chelates, were reacted with the above mentioned carbanions, and the coordinated central metal atom (e.g., AuIII, SnIV), which reveals considerable electronegativity, played a role of activating group. It could be easily removed from the system after reaction. A number of attempts to substitute hydrogen by carbon nucleophiles led to various products (addition of nucleophile to porphyrin ring, ligands substitution at metal center, etc.). These investigations were successfully finalized for meso-tetraphenylporphyrin–dichlorotin(IV) complex. Further development of this idea may open a new chapter in the functionalization of porphyrins.

Porphyrins, Gold and tin complexes, Nucleophilic substitution of hydrogen, Carbanions

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