![66. Modular, Step-Efficient Palladium-Catalyzed Cross-Coupling Strategy To Access C6-Heteroaryl 2-Aminopurine Ribonucleosides](https://cdn.prod.website-files.com/6380be6ed1140b78394d35e6/647f64aa109fe2abef7aa03d_images_medium_ol-2017-01602z_0006.gif)
Two Pd-catalyzed methods to access 6-heteroaryl 2-aminopurine ribonucleosides from 6-chloroguanosine are described. First, Pd-132-catalyzed Suzuki–Miyaura cross-coupling using a series of boron substrates and 6-chloroguanosine forms 6-heteroaryl-2-aminopurines in a single step. The versatility of 6-chloroguanosine is further demonstrated using a modified Sonogashira coupling employing potassium iodide as an additive. Finally, the utility of the 6-alkynyl-2-aminopurine ribonucleoside as a dipolarophile in [3 + 2] cycloadditions is presented, affording triazoles and isoxazoles when reacted with azide and isonitrile 1,3-dipoles, respectively.