Direct Synthesis of Methyl Chlorosilanes from Pd‐Mg‐SiO 2 Substrates Using Mechanochemistry

The direct reaction of methyl chloride with magnesium and palladium infused silica substrates to synthesize methyl chlorosilanes is reported. First, high energy ball milling on solid Mg‐SiO 2 mixtures produces elemental silicon and MgO. When PdCl 2 is infused into the mixture, after additional ball milling and high‐temperature reduction under H 2 , dipalladium silicide (Pd 2 Si) is produced. The silicon of the Pd 2 Si readily reacts with MeCl under Müller–Rochow reaction conditions, to produce methyl chlorosilanes at yield ratios analogous to those of the traditional process. The dominant product is Me 2 SiCl 2 (selectivity > 30%), followed by MeSiCl 3 and Me 3 SiCl, with minor amounts of the remaining chlorosilanes. Silicon conversion exceeds 20% for most of the substrates. The elemental palladium, which remains within the Pd‐Mg‐SiO 2 contact mass is re‐converted to Pd 2 Si at the next H 2 /high‐temperature treatment and reacts again with MeCl to repeat the methyl chlorosilane production. In principle, the resulting cycle of the mechanochemically induced formation of Pd 2 Si followed by the reaction with MeCl can be repeated until the starting SiO 2 converts completely to methyl chlorosilanes.