Pyrrolylmethylene Appended Corrorin: Peripheral Coordination and Transformation to Pyridyl Incorporated Hemiporphycene Analogue.

A pyrrolylmethylene appended corrorin 1 was synthesized and coordinated with [Rh(CO)2Cl]2 to afford 1-Rh with unique RhI-η2-CC bonding in addition to the coordination of the dipyrrin-like unit and a carbonyl ligand. Further oxidation of 1 afforded 2, exhibiting a hydrocorrorinone core, and it can be further transformed into pyrrolo[3,2-c]pyridine incorporated hemiporphycene analogue 3 upon treatment with HOAc. The side chain modifies the reactivity of corrorin and effectively tunes the NIR absorption of the resulting porphyrinoids.