Ruthenium catalysed C–H bond borylation

Abstract

An easily prepared series of phenylindenyldihydridosilyl ruthenium complexes (2a–2d) was obtained by reaction of tertiary silanes with the commercially-available [RuCl(3-phenylindenyl)(PPh₃)₂] (1). The [RuH₂(3-phenylindenyl)(SiEt₃)] (2a) complex was shown to be highly efficient (1.5 mol%) in the ortho-selective borylation of pyridyl substrates, with yields of up to 90%. A novel ruthenium(IV)-catalysed C–H activation borylation/functionalization reaction using a remarkably low catalyst loadings is described.