Abstract The reaction of methylchlorodisilanes with gem-polyhalides in the presence of organic bases has been investigated. The compounds CXCl 2 SiMeCl 2 (X= Cl, H, F and SiMeCl 2) were obtained in moderate to high yields from Cl 2 MeSiSiMeCl 2 and polyhalomethanes (eg, CCl 4, CHCl 3, CFCl 3 and CCl 3 SiMeCl 2) with PPh 3 or Bu 4 NCl as catalyst. The reaction of 1, 1, 2-trichlorotrimethyldisilane with CCl 4 afforded a 1: 1 ...