Multicomponent Domino Synthesis of Bis(imidazo[1,5-a]pyridine) Triarylmethane Iron(II) Complexes: Reaction Process...

Area of Science:

• Coordination Chemistry
• Organic Synthesis
• Photochemistry

Background:

• Iron complexes are investigated for their diverse chemical properties and potential applications.
• Multicomponent reactions offer efficient pathways for synthesizing complex molecules.
• Photoactivated chemotherapy is an emerging strategy for targeted cancer treatment.

Purpose of the Study:

• To synthesize novel iron(II) complexes with bis(imidazo[1,5-a]pyridine)-based triarylmethane ligands.
• To investigate the mechanism of the multicomponent domino reaction.
• To evaluate the photoactivated cytotoxicity of the synthesized iron(II) complexes against melanoma cells.

Main Methods:

• Facile synthesis of nine iron(II) complexes (Fe-1 ~ Fe-9) via a multicomponent domino reaction.
• Structure elucidation using single-crystal X-ray diffraction analysis.
• Reaction mechanism tracking using time-dependent electrospray ionization mass spectrometry.

Main Results:

• Successfully synthesized and characterized nine novel iron(II) complexes.
• Elucidated a highly organized domino reaction sequence involving aldimine condensation, cyclization, and nucleophilic addition.
• All complexes exhibited photoactivated cytotoxicity against B16F10 and A375 melanoma cells.
• Complex Fe-8 displayed potent photocytotoxicity (IC50 = 0.36 ± 0.06 µM for B16F10; 1.06 ± 0.42 µM for A375).

Conclusions:

• The developed multicomponent domino reaction provides an efficient route to novel iron(II) complexes.
• The synthesized iron(II) complexes hold promise as photodynamic agents for melanoma treatment.
• Fe-8's potent photocytotoxicity is attributed to light-triggered dual reactive oxygen species generation (hydroxyl radicals and singlet oxygen).