An isothiourea-catalyzed asymmetric [2,3]-rearrangement of allylic ammonium ylides

Benzotetramisole promotes the catalytic asymmetric [2,,3]-rearrangement of allylic quaternary ammonium salts (either isolated or prepared in situ from p-nitrophenyl bromoacetate and the corresponding allylic amine), generating syn-alpha-amino acid derivatives with excellent diastereo- and enantioselectivity (up to >95:5 dr; up to >99% ee).