Methods for positionally selective remote C−H functionalizations are in high demand. Herein, we disclose the first heterogeneous ruthenium catalyst for meta-selective C−H functionalizations, which enabled remote halogenations with excellent site selectivity and ample scope. The versatile heterogeneous Ru@SiO2catalyst was broadly applicable and could be easily recovered and reused, which set the stage for the direct fluorescent labeling of purines. In contrast to palladium, rhodium, iridium, or cobalt complexes, solely the ruthenium catalysis manifold provided access to meta-halogenated purine derivatives, illustrating the unique power of ruthenium C−H activation catalysis.
Bibliographical noteFunding Information:
Generous support by the European Research Council under the European Community's Seventh Framework Program (FP7 2007–2013/ERC Grant agreement No. 307535), the Chinese Scholarship Program (fellowship to C.Z.), the DFG (SFB 1073 C01), and the DAAD (fellowship to K.K.) is gratefully acknowledged. Furthermore, we thank Dr. Klaus Simon (University of Göttingen) for ICP-MS analyses.
© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
- C−H activation
- heterogeneous catalysis
- meta selectivity