Carbon-to-Carbon Anion Relay Chemistry: Facile Generation of Substituted Allyllithium Species

Treatment of [2‐(2‐bromophenyl)allyl]trimethylsilane with tBuLi in THF at –78 °C resulted in the rapid migration of the trimethylsilyl group to afford an allylic organolithium that can be easily trapped by a wide range of electrophiles. This is a rare example of a synthetically useful and efficientcarbon‐to‐carbon migration of a silicon group and represents a new approach to allylic organolithium species using anion relay chemistry. A relatively rare example of an anioniccarbon‐to‐carbon silicon shift results in the facile generation of a 2‐arylallylic organolithium species that can be trapped by avariety of electrophiles. Calculations suggestthat the shift of the silicon group from an allylic to an aryl position is enthalpically favored. A hypervalent silicon species does not appear to be an intermediate in the process.