INTRAMOLECULAR ANODIC OLEFIN COUPLING REACTIONS AND THE USE OF VINYLSILANES

Intramolecular anodic olefin coupling reactions involving vinylsilane groups have been studied. It was found that the previously successful predictive model for olefin coupling reactions based on an electrophilic attack of a radical cation onto an olefin did not successfully predict product formation for olefin coupling reactions involving vinylsilane terminating groups. Instead, these reactions were best described by viewing the initial addition of the radical cation to an olefin as if it occurred in a reversible ''radical-like'' fashion, in addition, reactions using a temporary silicon tether were shown to be compatible with the formation of quaternary carbons with control of relative stereochemistry. These reactions helped highlight the compatibility of the anodic olefin coupling reactions with extremely sensitive substrates. Finally, the results reported suggest that the mass balance of the intramolecular anodic olefin coupling reaction depends on the ease with which the initially formed cyclized product undergoes the second oxidation step.