Electrophile-Dependent Reactivity of Lithiated -Benzylpyrene-1-Carboxamide.

In this paper, we describe the lithiation of -benzylpyrene-1-carboxamide with RLi-TMEDA. We found that the reaction outcome strongly depends on the electrophile used in the quenching step. The electrophile can be introduced at either the benzylic position or at the C-2 position in the pyrene nucleus. Furthermore, when H was used as the quencher, the product of the intramolecular carbolithiation of the pyrene K-region was formed. Dehydrogenation of the obtained compound with DDQ allowed the synthesis of a novel nitrogen polycyclic compound with an aza-benzo[c,d]pyrene (azaolympicene) skeleton. Attempts to extend the reaction scope to the amides substituted in the phenyl ring and gave an unexpected result. The reaction of both compounds with BuLi gave 1-valerylpyrene () in good yield. Photophysical properties, including absorption spectra, emission spectra and quantum yields of the emission of selected products, were studied and discussed.