Enhancing Precatalyst Performance and Robustness through Aromaticity: Insights from Iridaheteroaromatics

Area of Science:

• Organometallic Chemistry
• Catalysis
• Heterocyclic Chemistry

Background:

• Metallaaromatic catalysts, despite stability benefits from dπ-pπ conjugation, are underutilized.
• Existing metallaaromatic catalysts show reactivity in stoichiometric reactions but limited catalytic applications.
• There is a need for stable and versatile metallaaromatic catalysts for broad organic transformations.

Purpose of the Study:

• To develop a synthetic strategy for a diverse range of stable iridaheteroaromatic catalysts.
• To investigate the electronic and structural properties contributing to catalyst stability and reactivity.
• To evaluate the catalytic performance of these novel catalysts in various organic transformations.

Main Methods:

• Synthesis of iridaheteroaromatics, including iridapyridylidene-indole, iridapyridene-indole, and iridaimidazole, via in situ deprotonation/metalation.
• Characterization using spectroscopic data, X-ray crystallography, and density functional theory (DFT) calculations.
• Catalytic testing in cross-alkylation, β-alkylation of alcohols, quinolone synthesis, and bioalcohol self-condensation.

Main Results:

• Successful synthesis of diverse iridaheteroaromatics with confirmed aromaticity and enhanced electronic properties.
• Demonstrated high catalytic activity, selectivity, and turnover frequencies (TOFs) in key organic reactions.
• Effective application in eco-friendly quinolone synthesis and self-condensation of bioalcohols in water.

Conclusions:

• The synthesized iridaheteroaromatics are stable, versatile metallaaromatic catalysts with significant potential.
• These catalysts offer a robust platform for industrially relevant transformations under mild and eco-friendly conditions.
• The findings highlight practical applications beyond theoretical importance, paving the way for large-scale catalytic processes.