Work

Synthesis of silylated polycyclic aromatic hydrocarbons by lithium-mediated mechanochemical Birch reductive silylation

Year: 2026

Type: article

Abstract: Silicon-substituted polycyclic aromatic hydrocarbons (Si-PAHs) are important functional π-conjugated molecules, but their synthesis is still largely dependent on the multistep preparation of precursors, such as halogenated PAHs. Herein, we report a lithium-mediated mechanochemical Birch reductive silylation of unfunctionalized PAHs in air at room temperature. Various silylated PAHs (Si-PAHs) and hydrogenated analogues were obtained directly from unfunctionalized PAHs by ball-milling PAHs with bulk Li(0) in a small amount of THF additive, followed by treatment with chlorosilanes, fluorosilanes, or hydrosilanes. This method accommodates a range of PAHs, including chrysene, fluoranthene, and perylene derivatives, and enables access to various substitution patterns that are difficult to achieve using conventional synthetic methods. The resulting Si-PAHs exhibit enhanced solubility and fluorescent quantum yields, along with a characteristic red shift in absorption and emission. Furthermore, the combination of the previously developed Li(0)-mediated mechanochemical cyclodehydrogenation and Birch reductive arylation with the present silylation enabled one-pot access to more complicated functional Si-PAHs.

Source: Chemical Science

DOI: 10.1039/d6sc05649k

Authors: Shota Mikawa, Yoshifumi Toyama, Hideto Ito

Institution: Nagoya University

Language: English

Topic: Organoboron and organosilicon chemistry

Subfield: Organic Chemistry

Field: Chemistry

Domain: Physical Sciences

Open Access status: diamond

Funders: Support for Pioneering Research Initiated by the Next Generation, Mazda Foundation, Sumitomo Foundation, Japan Society for the Promotion of Science

Awards: G6538902846, G7559972709, G9000846284