Expanding the diversity of purine libraries

In recent years, there has been a resurgence of interest in the synthesis o f purine derivatives due to the discovery of purine-derived ligands for a v ariety of nucleotide dependent enzymes. The majority of chemistry has focus ed on substitution of the purine core structure by alkylation at N9 and nuc leophilic-aromatic substitution reactions at C2 and C6. Here we report the syntheses of aryl, N-aryl, O-aryl substituted purine libraries by the palla dium-mediated coupling of boronic acids, anilines or phenols at the C2 posi tion, and copper(II)-mediated N-arylation with boronic acids at the N9 posi tion. The chemistry described here greatly expands our ability to introduce different functionality and create new purine scaffolds. (C) 2001 Publishe d by Elsevier Science Ltd.