Reaction Mechanism of Silylation of C−O Bonds in Alkyl Ethers over Supported Gold Catalysts: Experimental and Theoretical Investigations

Abstract

The reaction mechanism of α-Fe₂O₃-supported Au-catalyzed silylation of ether C(sp³)–O bonds by disilane is investigated using both experimental and computational approaches. The experimental study reveals that the ether activation is the rate-determining step in the silylation of C(sp³)–O bonds and that this reaction proceeds via the S_H2-type mechanism involving radical species. DFT calculations demonstrate that the Si–Si bond cleavage in disilane occurs at the interface between Au cluster and α-Fe₂O₃ support with a low activation energy and that the subsequent attack by silyl radicals on the ether involves an energy barrier consistent with the experimental results. These investigations provide valuable insights into the unique reaction mechanism of ether C(sp³)–O bond activation, which could serve as a basis for the development of novel supported metal catalyst systems.