1 research outputs found
Synthesis and Reactivity of Triazaphenanthrenes
Pyridonaphthyridines
(triazaphenanthrenes) were prepared in 4 steps and in 13–52%
overall yield using Negishi cross-couplings between iodopicolines
and 2-chloro-pyridylzinc derivatives. After chlorination, Gabriel
amination and spontaneous ring-closure, the final aromatization leading
to the triazaphenanthrenes was achieved with chloranil. This heterocyclic
scaffold underwent a nucleophilic addition at position 6 leading to
further functionalized pyridonaphthyridines. The influence of these
chemical modifications on the optical properties was studied by steady-state
and time-resolved optical spectroscopy. While the thiophene-substituted
heterocycles exhibited the most extended absorption, the phenyl- and
furan-substituted compounds showed a stronger photoluminescence, reaching
above 20% quantum yield and lifetimes of several nanoseconds