Titanocene-Mediated Dinitrile Coupling: A Divergent Route to Nitrogen-Containing Polycyclic Aromatic Hydrocarbons.
Gavin R KielAdrian E SamkianAmélie NicolayRyan J WitzkeT Don TilleyPublished in: Journal of the American Chemical Society (2018)
A general synthetic strategy for the construction of large, nitrogen-containing polycyclic aromatic hydrocarbons (PAHs) is reported. The strategy involves two key steps: (1) a titanocene-mediated reductive cyclization of an oligo(dinitrile) precursor to form a PAH appended with di(aza)titanacyclopentadiene functionality; (2) a divergent titanocene transfer reaction, which allows final-step installation of one or more o-quinone, diazole, or pyrazine units into the PAH framework. The new methodology enables rational, late-stage control of HOMO and LUMO energy levels and thus photophysical and electrochemical properties, as revealed by UV/vis and fluorescence spectroscopy, cyclic voltammetry, and DFT calculations. More generally, this contribution presents the first productive use of di(aza)metallacyclopentadiene intermediates in organic synthesis, including the first formal [2 + 2 + 2] reaction to form a pyrazine ring.
Keyphrases
- polycyclic aromatic hydrocarbons
- electron transfer
- density functional theory
- single molecule
- biofilm formation
- gold nanoparticles
- molecular dynamics
- ionic liquid
- room temperature
- cystic fibrosis
- risk assessment
- pseudomonas aeruginosa
- solid state
- energy transfer
- mass spectrometry
- staphylococcus aureus
- molecularly imprinted