applicability of this methodology to significantly larger peptides.
The high level of trans selectivity, coupled with the ease of synthesis
of the precursors, suggest this reaction could have a number of
applications in chemical biology.
The authors would like to thank Novartis and CEM UK for
support of this work. We also gratefully acknowledge BBSRC,
EPSRC, CEM Microwave Technology, GSK, AstraZeneca for
support and the EPSRC Mass Spectroscopy Service at Swansea.
3 Examples of selective cross-metathesis as a means to functionalizing
side-chains include: (a) S. H. Liu and R. N. Ben, Org. Lett., 2005,
7, 2385–2388; (b) E. G. Nolen, C. J. Fedorka and B. Blicher, Synth.
Commun., 2006, 36, 1707–1713; (c) E. Enholm and T. J. Low, J. Org.
Chem., 2006, 71, 2272–2276; (d) F. W. Schmidtmann, T. E. Benedum
and G. J. McGarvey, Tetrahedron Lett., 2005, 46, 4677–4681; (e) A. J.
Vernall and A. D. Abell, Org. Biomol. Chem., 2004, 2, 2555–2557; (f) S. E.
Gibson, V. C. Gibson and S. P. Keen, Chem. Commun., 1997, 1107–1108.
4 R. H. Grubbs, C. W. Lee, S. Ding and M. Scholl, Org. Lett., 1999, 1,
953–956.
5 An explanation of selectivity in cross-metathesis can be found in: A. K.
Chatterjee, T. L. Choi, D. P. Sanders and R. H. Grubbs, J. Am. Chem.
Soc., 2003, 125, 11360–11370.
6 For microwave enhancement of self cross-metathesis, see: S. A. Poulsen
and L. F. Bornaghi, Tetrahedron Lett., 2005, 46, 7389–7392; for the
enhancement of cross-metathesis, see:; F. C. Bargiggia and W. V. Murray,
J. Org. Chem., 2005, 70, 9636–9639.
7 A. K. Chatterjee, in Handbook of Metathesis, 1st edn., vol. 2, ed.
R. H. Grubbs, Wiley-VCH: Weinheim, 2003, ch. 8, pp. 246–292.
8 Benzyl protected serine has been shown to be particularly sensitive to
racemization via oxazolone rearrangement during coupling reactions in
DCM: C. Griel, A. Kolbe and S. Merkel, J. Chem. Soc., Perkin Trans. 2,
1996, 11, 2525–2529.
9 (a) R. von Eggelkraut-Gottanka, A. Klose, A. G. Beck-Sickinger and
M. Beyermann, Tetrahedron Lett., 2003, 44, 3551–3554; (b) P. Henklein,
K. Bruns, M. Nimtz, V. Wray, U. Tessmer and U. Schubert, J. Pept. Sci.,
2005, 11, 481–490; (c) S. E. Paramonov, V. Gauba and J. D. Hartgerink,
Macromolecules, 2005, 38, 7555–7561; (d) A. Saporito, D. Marasco, A.
Chambery, P. Botti, S. M. Monti, C. Pedone and M. Ruvo, Biopolymers,
2006, 83, 508–518.
Notes and references
1 Y. W. Fu, J. Bieschke and J. W. Kelly, J. Am. Chem. Soc., 2005, 127,
15366–15367.
2 Ring-closing metathesis has found several applications which include:
(a) preparation of a hydrogen-bond surrogate derived artificial a-helix:
G. Dimartino, D. Y. Wang, R. N. Chapman and P. S. Arora, Org. Lett.,
2005, 7, 2389–2392; (b) bridging a cyclic hexapeptide: J. Giovannoni, C.
Didierjean, P. Durand, M. Marraud, A. Aubry, P. Renaut, J. Martinez
and M. Amblard, Org. Lett., 2004, 6, 3449–3452; (c) RCM of alkynes
has yielded sulfide bridge mimics: N. Ghalit, A. J. Poot, A. Furstner,
D. T. S. Rijkers and R. M. J. Liskamp, Org. Lett., 2005, 7, 2961–2964.
Examples of self cross-metathesis which have come to our attention are:;
(d) S. A. Poulsen and L. F. Bornaghi, Tetrahedron Lett., 2005, 46, 7389–
7392; (e) E. G. Nolen, C. J. Fedorka and B. Blicher, Synth. Commun.,
2006, 36, 1707–1713; (f) J. Streuff, M. Nieger and K. Muniz, Chem.–
Eur. J., 2006, 12, 4362–4371, which also includes an example of a purely
statistical cross-metathesis.
This journal is
The Royal Society of Chemistry 2007
Org. Biomol. Chem., 2007, 5, 1025–1027 | 1027
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