Synthesis of a New Type of Bis(acylsilanes) Starting from 2-Alkyl- or 2-Phenyl-1,3-dithiane and Bis(chlorinated) Disilane or Disiloxane

New bis(acylsilanes) 17-19 bearing silicon atoms in an internal position were synthesized via silylation of 2-lithio-2-substituted-1,3-dithianes with bis(chlorinated) disilane 10 or siloxanes 11, 12. The dethioketalization of bis(dithianes) intermediates was performed using iodine and calcium carbonate. The method was efficient and general for linear and substituted alkyl chain derivatives but gave low yields for the aromatic compound 18d.