Preparation of 1,7- and 3,9-Dideazapurines from 2‑Amino-3-iodo- and 3‑Amino-4-iodopyridines and Activated Acetylenes by Conjugate Addition and Copper-Catalyzed Intramolecular Arylation
journal contributionposted on 21.11.2014, 00:00 authored by Ying Zhu, Thomas G. Back
The conjugate addition of N-formyl derivatives of 2-amino-3-iodo- and 3-amino-4-iodopyridines to acetylenes activated by sulfone, ester, or ketone groups, followed by intramolecular arylation, affords variously substituted 1,7- and 3,9-dideazapurines. The method employs DMF–water as the solvent and copper(II) acetate as the catalyst for the cyclization step. Neither added ligands nor the exclusion of oxygen is necessary. The process therefore provides a simple, convenient, and inexpensive route to this biologically interesting class of products.