UG forms a highly stable quadruply hydrogen-bonded heterocomplex with DAN, but the fidelity of the complex is lowered somewhat by the Hoogsteen-side oligomerization of UG (Kassoc ∼ 230 M-1, CDCl 3). DeUG was prepared as a more robust analogue of UG lacking the Hoogsteen nitrogen atom. Remarkably, the deaza analogue, DeUG, forms a much more stable complex with DAN (>10-fold higher Kassoc for DeUG-DAN vs UG-DAN) but also dimerizes more strongly (Kdim = 880 ± 40 M-1, CDCl3) by adopting a conformation preorganized for both binding and dimerization.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Organic Chemistry