One-pot synthesis of α-amino acids based on free radical-mediated carbon–carbon bond formation

(Note: The full text of this document is currently only available in the PDF Version )

Hideto Miyabe, Naoko Yoshioka, Masafumi Ueda and Takeaki Naito


Abstract

The one-pot reaction of 2-hydroxy-2-methoxyacetic acid methyl ester with benzyloxyamine and an alkyl radical provided a convenient method for preparing the protected α-amino acids via a carbon–carbon bond formation by intermolecular carbon radical addition to glyoxylic oxime ether.


References

  1. (a) R. M. Williams, Synthesis of Optically Active a-Amino Acids, Pergamon Press, Oxford, 1989 Search PubMed; (b) R. O. Duthaler, Tetrahedron, 1994, 50, 1539 CrossRef CAS.
  2. (a) P. A. Tempest, S. D. Brown and R. W. Armstrong, Angew. Chem., Int. Ed. Engl., 1996, 35, 640 Search PubMed; (b) G. H. Posner, Chem. Rev., 1986, 86, 831 CrossRef CAS.
  3. (a) N. A. Petasis and I. A. Zavialov, J. Am. Chem. Soc., 1997, 119, 445 CrossRef CAS; (b) N. A. Petasis, A. Goodman and I. A. Zavialov, Tetrahedron, 1997, 53, 16463 CrossRef CAS.
  4. (a) H. Miyabe, R. Shibata, C. Ushiro and T. Naito, Tetrahedron Lett., 1998, 39, 631 CrossRef CAS; (b) H. Miyabe, C. Ushiro and T. Naito, Chem. Commun., 1997, 1789 RSC; (c) H. Miyabe, R. Shibata, M. Sangawa, C. Ushiro and T. Naito, Tetrahedron, 1998, 54, 11431 CrossRef CAS.
  5. Oxime ethers are well known to be excellent radical acceptors because of the extra stabilisation of the intermediate aminyl radical provided by the adjacent oxygen atom. See H. Miyabe, M. Torieda, K. Inoue, K. Tajiri, T. Kiguchi and T. Naito, J. Org. Chem., 1998, 63, 4397 Search PubMed and references cited therein.
  6. For a related example, high 1,3-stereoinduction in radical additions to glyoxylate imines has recently been reported. See M. P. Bertrand, L. Feray, R. Nouguier and L. Stella, Synlett, 1998, 780 Search PubMed.
  7. K. Nozaki, K. Oshima and K. Utimoto, Bull. Chem. Soc. Jpn., 1991, 64, 403 CAS.
  8. (a) Y. Yamamoto and W. Ito, Tetrahedron, 1988, 44, 5415 CrossRef CAS; (b) T. Kolasa, S. K. Sharma and M. J. Miller, Tetrahedron, 1988, 44, 5431 CrossRef CAS; (c) J.-C. Fiaud and H. B. Kagan, Tetrahedron Lett., 1971, 1019 CrossRef CAS; (d) J.-C. Fiaud and H. B. Kagan, Tetrahedron Lett., 1970, 1813 CrossRef CAS.
  9. For recent examples, the nucleophilic addition of allylic zinc reagents to glyoxylic oxime ethers proceeds regioselectively to give the C-alkylated products. See (a) S. Hanessian and R.-Y. Yang, Tetrahedron Lett., 1996, 37, 8997 CrossRef CAS; (b) S. Hanessian and R.-Y. Yang, Tetrahedron Lett., 1996, 37, 5273 CrossRef CAS.
Click here to see how this site uses Cookies. View our privacy policy here.