Propargylidyne and Pentadiynylidyne Polyfunctionalised Polycyclic Aromatic Hydrocarbons

Area of Science:

• Organometallic Chemistry
• Synthetic Organic Chemistry
• Materials Science

Background:

• Tungsten carbynes are versatile building blocks in organometallic chemistry.
• Cross-coupling reactions are essential for constructing complex organic molecules.
• Polycyclic aromatic hydrocarbons (PAHs) have unique electronic and optical properties.

Purpose of the Study:

• To develop a novel synthetic route to polycyclic aromatic hydrocarbon propargylidynes.
• To explore the synthesis of multi-functionalized tungsten-alkyne complexes.
• To expand the scope of [C1+C2] cross-coupling reactions involving tungsten carbynes.

Main Methods:

• Palladium(0)/Gold(I) mediated [C1+C2] cross-coupling reactions.
• Utilizing tungsten carbynes [W(≡CBr)(CO)2(Tp*)] (Tp*=hydrotris(dimethylpyrazolyl)borate) as electrophilic partners.
• Employing trimethylsilylethynyl-substituted arenes as nucleophilic partners.

Main Results:

• Successful synthesis of new polycyclic aromatic hydrocarbon propargylidynes [W(≡CC≡CR)(CO)2(Tp*)] (R=9-anthracenyl, 1-pyrenyl).
• Demonstration of the strategy for creating bis(propargylidyne) and bis(pentadiynylidyne) complexes with phenyl or anthracenyl linkers.
• Synthesis of a tetrakis(propargylidyne) complex bridged by a pyrene core.

Conclusions:

• The developed Pd/Au-catalyzed method provides efficient access to novel tungsten-based polycyclic aromatic hydrocarbon propargylidynes.
• This approach enables the construction of complex, multi-alkyne functionalized organometallic compounds.
• The synthesized complexes hold potential for applications in catalysis, materials science, and molecular electronics.