Synlett 2012; 23(12): 1849-1850
DOI: 10.1055/s-0031-1290443
© Georg Thieme Verlag Stuttgart · New York

1-{[1-(Cyano-2-ethoxy-2-oxo-ethylidenaminooxy)dimethylaminomorpholinomethylene]}methane-aminium hexafluorophosphate

Julián Bergueiro Álvarez
Departamento de Química Orgánica, Universidad de Santiago de Compostela, Avenida de las Ciencias S/N, Campus Sur, 15782 ­Santiago de Compostela, Spain, Email:
› Author Affiliations
Further Information

Publication History

Publication Date:
05 July 2012 (online)


Peptide coupling reagents are rapidly evolving in the last years from the classical carbodiimide methods to a second generation onium salts based reactives,[ 1 ] and nowadays the novel uronium-type reagents derived from Oxyma like 1-{[1-(Cyano-2-ethoxy-2-oxoethylidenaminooxy)dimethyl­aminomorpholinomethylene]}methaneaminium hexafluo­rophosphate (COMU) introduced by Albericio’s group.[ 2 ] This third generation peptide coupling reagent is soluble and stable due to the presence of morpholin.[ 2b ] By-products are water-soluble and easy to remove, making COMU an excellent choice as coupling reagent in solid- and liquid-phase peptide synthesis.[ 3 ] In addition, COMU shows a less hazardous safety profile than benzotriazole-based reagents like HATU and HBTU, which exhibit unpredictable autocatalytic decomposition and therefore a higher risk of explosion, and cause allergic reactions. COMU gives better results than aza derivatives in the presence of only one equivalent of base, and no activation time is required reducing the common racemization problem. Further, the couplings can be monitored by advantageous visual or colorimetric reaction. Although commercially available, COMU can be prepared easily (Scheme [1]).[2a] [4]

Zoom Image
Scheme 1 Synthesis of COMU
  • References

  • 1 Albericio F, Bofill JM, El-Faham A, Kates SA. J. Org. Chem. 1998; 63: 9678
    • 2a El-Faham A, Subirós R, Prohens R, Albericio F. Chem.–Eur. J. 2009; 15: 9404
    • 2b El-Faham A, Albericio F. J. Pept. Sci. 2010; 16: 6
    • 2c El-Faham A, Albericio F. Chem. Rev. 2011; 111: 6557
    • 3a Mali L, Tofteng AP, Pedersen SL, Sorensen KK, Jensen KJ. J. Pept. Sci. 2010; 16: 506
    • 3b Chantell CA, Onaiyekan MA, Menakuru M. J. Pept. Sci. 2012; 18: 88
    • 3c Hjorringgaard CU, Brust A, Alewood PF. J. Pept. Sci. 2012; 18: 199
  • 4 Al-Warhi TI, Al-Hazimi HM. A, El-Faham A, Albericio F. Molecules 2010; 15: 9403
  • 5 Subiros-Funosas R, Acosta GA, El-Faham A, Albericio F. Tetrahedron Lett. 2009; 50: 6200
  • 6 Yamada K, Nagashima I, Hachisu M, Matsuo I, Shimizu H. Tetrahedron Lett. 2012; 53: 1066
    • 7a Hjelmgaard T, Faure S, Staerk D, Taillefumier C, Nielsen J. Org. Biomol. Chem. 2011; 9: 6832
    • 7b Hjelmgaard T, Faure S, Staerk D, Taillefumier C, Nielsen J. Eur. J. Org. Chem. 2011; 4121
  • 8 Marcucci E, Tulla-Puche J, Albericio F. Org. Lett. 2012; 14: 612
  • 9 Zhang M, Zhang Y, Lu W, Nan F-J. Org. Biomol. Chem. 2011; 9: 4436
  • 10 Tyrrell E, Brawn P, Carew M, Greenwood I. Tetrahedron Lett. 2011; 52: 369
  • 11 Maier M, Kotman N, Friedrichs C, Andrieu J, Wagner M, Graf R, Strauss WS. L, Mailander V, Weiss CK, Landfester K. Macromolecules 2011; 44: 6258
  • 12 Brandt GE. L, Blagg BS. J. ACS Med. Chem. Lett. 2011; 2: 735