Iridium-catalyzed orthoÀ CÀ H silylation of 2-arylpyridine derivative with hydrosilane by using phosphine-borane ligand has been developed. A variety of 2-arylpyridines could be used for this reaction to give mono-and disilylated products in 81-99% yields. In this reaction, the length of linkage between phosphorus and boron plays an important role for the reaction to proceed. We consider that the nitrogen in 2-arylpyridine coordinates to Lewis acidic boron in the ligand and thus the iridium is led to an orthoÀ CÀ H bond to cleave it.

No abstract