Double axial chirality promoted asymmetric [2,3] Stevens rearrangement of N-cinnamyl l-alanine amide-derived ammonium ylides†
Abstract
The base-induced asymmetric [2,3] Stevens rearrangement of N-cinnamyl tetraalkylammonium ylides derived from L-alanine amides proceeds via a double axially chiral intermediate to afford the corresponding α-substituted alanine derivatives with high enantio- and diastereoselectivities.