Enantioselective α-allylation of a phenylalanine derivative under the control of aggregation of a chiral nonracemic enolate

α-Allylation of 3 took place upon treatment with KHMDS followed by allylic halides in 82–87% ee in the absence of external chiral sources. A chiral nonracemic enolate with intramolecular aggregation (D) is expected to be an intermediate.