Acyclic ene-carbamate. A useful tool for an original synthesis of phosphine-containing α-amino acids bearing a quaternary carbon

A novel and efficient approach for the synthesis of phosphine-containing α-amino acids bearing quaternary carbon is described. The key step involves the original nucleophilic addition of lithiated phosphines onto acyclic ene-carbamates concomitant with a spontaneous internal (N→C) alkyloxycarbonyl migration.