Direct Access of Heteroaryl Difunctional Monomers for Arene-Enriched Polysiloxane Synthesis

Step- and atom-economical catalytic C-H silylations were developed to prepare heteroaryl alkoxysilane monomers for silicone materials. The silylations are operable in the presence of 1-3 mol % of a well-defined Rh complex to afford the desired aryl monomers in up to 95% yield. The preformed complexes are able to suppress silane redistribution side reactions so as to improve overall efficiency of less reactive HSiMe(OEt)₂. The resulting monomers will broaden the scope of aryl substituents that is currently limited to only phenyl groups, so that various polysiloxanes bearing nonphenyl aryl substituents can be readily prepared with modulating physical and chemical properties.