PREPARATION OF A DIVERSE PURINE-SCAFFOLD LIBRARY VIA ONE-STEP PALLADIUM CATALYZED CROSS-COUPLING

In our ongoing efforts to prepare Hsp90 inhibitors, various cross-coupling reactions (Suzuki, Stille, Heck, and Sonogashira) were used to construct a diverse library of substituted purines in a single step from PU-H71 (1). We show that these reactions, particularly Suzuki coupling, are highly efficient, do not require protection of the pendant amine, and due to the wide variety of commercially available substrates, allow for the rapid development of a diverse purine library. The products derived from these reactions will enable us to explore the chemical space occupied by the key 6'-iodine of PU-H71 through molecules with diverse physical and chemical properties with the potential to be useful for diseases in which Hsp90 is implicated.