Anodic oxidation of α-silylacetic acid Ph2(Me)SiCH2COOH: Decarboxylation versus desilylation

Constant current electrolysis of Ph2(Me)SiCH2COOH in methanol under non-Kolbe conditions (carbon anode, low current density) undergoes two competing reactions: decarboxylation and desilylation. The oxidative-decarboxylation process involves both 1e− and 2e− and affords a Kolbe ‘dimer’ [Ph2(Me)SiCH2CH2Si(Me)Ph2] and non-Kolbe products of type Ph2(Me)SiCH2OCH3 and Ph2(Me)SiCH2OH, respectively, whereas the 1e− desilylation process gives silylated products of type Ph2(Me)SiOH, Ph2(Me)SiOCH3, Ph(Me)Si(OCH3)2 and the siloxane Ph2(Me)SiOSi(Me)Ph2. The effects of the polarity of the media and temperature on these two pathways have been investigated.

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