First Example of a Chlorophin from an Unexpected Oxidative Ring‐Opening of an (Octadehydrocorrinato)nickel(<scp>II</scp>) Salt

Abstract

A tetraazamacrocycle from three pyrrole units and a condensed furan ring—“furochloro-phin”—surrounds the NiII ion in 1. This 18π electron system with a basic chlorin structure is formed surprisingly easily from the thermolysis of (octadehydrocorrinato)nickel(II) chloride. This synthesis will probably not only provide new impetus for corrinoid chemistry; but the absorption characteristics of the metal complex and the free base make these interesting compounds for applications in photodynamic cancer therapy.