Regioselectivity of the C‑Metalation of 6‑Furylpurine: Importance of Directing Effects

We report the C-metalation of 6-furylpurine with Pt²⁺, Pd²⁺, and Hg²⁺. The ligand binds the metal ions in a bidentate fashion, involving the N7 purine atom and one of the furyl carbon atoms. The regioselectivity is determined by the metal ion. Pt²⁺ and Pd²⁺ coordinate the furyl moiety in its β position and Hg²⁺ in its electronically preferred α position.