1. R. M. Williams, Synthesis of Optically Active α-Amino Acids, Pergamon Press, 1989; H. Heimgartner, Angew. Chem. Int. Ed. Engl., 1991, 30, 238; R. O. Duthaler, Tetrahedron, 1994, 50, 1539; D. Seebach, A. R. Sting, M. Hoffmann, Angew. Chem. Int. Ed. Engl., 1996, 35, 2708; T. Wirth, Angew. Chem. Int. Ed. Engl., 1997, 36, 225; R. Chinchilla, L. R. Falvello, N. Galindo, C. Nájera, Angew. Chem. Int. Ed. Engl., 1997, 36, 995.
2. C. Deng, U. Groth, U. Schöllkopf, Angew. Chem. Int. Ed. Engl., 1981, 21, 798; U. Schöllkopf, Pure Appl. Chem., 1983, 55, 1799; U. Schöllkopf, U. Busse, R. Lonsky, R. Hinrichs, Liebigs Ann. Chem., 1986, 2150.
3. Recent examples where 1 has been successfully employed for the asymmetric synthesis of complex non proteinogenic α-amino acids include V. Ojea, C. Fernández, M. Ruiz, J. M. Quintela, Tetrahedron Lett., 1996, 32, 5801; A. J. Pearson, H. Shin, J. Org. Chem., 1994, 59, 2314; R. Mueller, L. Revesz, Tetrahedron Lett., 1994, 35, 4091; M. Ohba, T. Mukaihira, T. Fujii, Chem. Pharm. Bull., 1994, 42, 1784; J. Paladino, C. Guyard, C. Thurieau, J. Fauchère, Helv. Chim. Acta., 1993, 76, 2465; J. E. Baldwin, R. M. Adlington, M. B. Mitchell, J. Chem. Soc., Chem. Commun., 1993, 1332.
4. 1 is commercially available in limited quantities at high cost (£219 for 5 ml) from Fluka/Merck–Schuchardt.
5. J. E. Rose, P. D. Leeson, D. Gani, J. Chem. Soc., Perkin Trans. 1, 1995, 157.