Non-defluorinative electrochemical silylation of ethyl trifluoroacetate: a practical synthesis of trifluoroacetyltrimethylsilane via its ethyltrimethylsilyl ketal

Abstract An efficient method for the preparation of original trifluoroacetyltrimethylsilane, CF 3 COSiMe 3 ( 3 ), in two steps from readily available ethyl trifluoroacetate is described. Electrochemical reduction of this ester using a sacrificial anode and performed on a semimolar scale afforded the unprecedented corresponding ketal, CF 3 C(SiMe 3 )(OSiMe 3 )OEt ( 2 ) in 30–56% isolated yield. Treated with concentrated sulphuric acid at room temperature, the latter directly led to pure acylsilane 3 in 86% yield.