Imidazolyl-phenyl (IMP) anions: a modular structure for tuning solubility and coordinating ability

Area of Science:

• Organometallic Chemistry
• Supramolecular Chemistry
• Catalysis

Background:

• Anion-cation interactions significantly influence solution-phase reactivity, impacting synthesis and catalysis.
• Probing and controlling these interactions presents a persistent challenge in chemistry.

Purpose of the Study:

• To synthesize and characterize a novel family of tunable anions, termed IMP anions.
• To investigate the coordinating ability and reactivity of IMP anions in organometallic chemistry and catalysis.

Main Methods:

• Synthesis of IMP anions via deprotonation of substituted 2-phenylimidazoles followed by reaction with B(C6F5)3.
• Characterization using spectroscopic methods and X-ray crystallography.
• Evaluation of catalytic activity in gold-catalyzed reactions, including cyclization and hydroalkoxylation.

Main Results:

• A range of IMP anions with diverse functional groups (nitro, ester, amide, amine, alcohol) were synthesized.
• The coordinating ability of IMP anions was shown to be tunable, falling between BF4- and BArF4- based on substituent polarity.
• Novel gold complexes were isolated, including the first X-ray structure of a (η2-diphenylacetylene)Au complex.
• IMP anions facilitated efficient gold-catalyzed cyclization and hydroalkoxylation reactions, outperforming traditional anions in specific solvents like toluene.

Conclusions:

• IMP anions offer a versatile platform for tuning anion-cation interactions in solution.
• Their robustness, tunable coordinating ability, and solubility make them effective for stabilizing reactive species and promoting homogeneous catalysis.
• This work provides a new tool for advancing organometallic synthesis and catalytic applications.