Silver‐Catalyzed Direct C6–H Arylation of Purines and Purine Nucleosides with Arylboronic Acids

A practical and operationally simple protocol for the assembly of 6‐aryl‐substituted purines through the direct C6–H arylation of purines and 8‐azapurine and purine nucleosides from arylboronic acids was developed. This reaction was performed under ambient conditions with ammonium persulfate as the oxidant in the presence of silver(I). The reaction was found to be regioselective with the arylation occurring predominantly at the C6 position, and a large variety of functional groups, including halides, esters, hydroxy groups, and heterocycles, were tolerated. An efficient protocol for the direct C6–H arylation of purines and purine nucleosides is described under the catalysis of silver nitrate and under ambient conditions. A wide assortment of purines and arylboronic acids can be employed in this process to afford C6‐arylpurines and purine nucleosides with high regioselectivity. TFA = trifluoroacetic acid; DCE = 1,2‐dichloroethane.