Iridium-catalyzed intermolecular dehydrogenative silylation of polycyclic aromatic compounds without directing groups

Area of Science:

• Organic Chemistry
• Catalysis
• Materials Science

Background:

• Direct C-H functionalization is a key strategy in modern organic synthesis.
• Polycyclic aromatic compounds (PACs) are important in materials science but challenging to functionalize selectively.
• Existing methods often require directing groups or harsh conditions.

Purpose of the Study:

• To develop a novel iridium-catalyzed method for the direct dehydrogenative silylation of C(sp(2))-H bonds in PACs.
• To achieve functionalization without the need for directing groups.
• To explore the scope and selectivity of this new reaction.

Main Methods:

• Iridium-catalyzed intermolecular dehydrogenative silylation reaction.
• Utilized C(sp(2))-H bond activation and Si-H bond activation.
• Investigated the effect of electronic and steric factors on reactivity and selectivity.

Main Results:

• Successfully synthesized various arylsilanes from PACs.
• Hydrogen gas was the only byproduct, indicating a highly atom-economical process.
• Reactivity was influenced by the electronic properties of the aromatic compounds, with efficient silylation of electron-deficient PACs.
• Site-selectivity was primarily governed by steric hindrance.

Conclusions:

• Developed a novel, directing-group-free method for C-H silylation of PACs.
• The reaction exhibits unique chemo- and site-selectivity, distinct from electrophilic functionalization.
• This method provides a valuable tool for synthesizing functionalized PACs and arylsilanes.