Fig. 3. Substrate-based mechanistic probes point to the role of the N7 of guanine in directing the chemoselectivity. Only the dGMP starting material leads to efficient reaction. HPLC traces were recorded after 30 min reaction time. Reaction conditions: 5 mM substrate (dGMP or deaza-dGTP or TMP or α-valerolactone), 1 mM CuSO4, 5 mM ascorbate, 50 mM EDA, 100 mM MES pH 6, dioxane 20% (v/v), H2O, 25 °C.
