Organophosphorus-Catalysed Staudinger Reduction
[6] a) D. J. C. Constable, P. J. Dunn, J. D. Hayler, G. R.
Humphrey, J. L. Leazer Jr, R. J. Linderman, K. Lorenz,
J. Manley, B. A. Pearlman, A. Wells, A. Zaks, T. Y.
Zhang, Green Chem. 2007, 9, 411–420; b) B. M. Trost,
Science 1991, 254, 1471–1477.
[7] a) S. P. Marsden, Nature Chemistry 2009, 1, 685–687;
b) I. J. S. Fairlamb, ChemSusChem 2009, 2, 1021–1024.
[8] a) S. P. Marsden, A. E. McGonagle, B. McKeever-
Abbas, Org. Lett. 2008, 10, 2589–2591; b) R. M.
Denton, J. An, B. Adeniran, Chem. Commun. 2010,
3025–3027; c) R. M. Denton, X. Tang, A. Przeslak, Org.
Lett. 2010, 12, 4678–4681; d) R. M. Denton, J. An, B.
Adeniran, A. J. Blake, W. Lewis, A. M. Poulton, J. Org.
Chem. 2011, 76, 6749–6767.
In summary, we have developed the first Staudinger
reduction that is catalytic in phosphine, involving in
situ P=N bond reduction. Our procedure offers the
advantage of less waste, with catalyst loading down to
5%. In addition, the reaction is practically simple and
displays high functional group tolerance. Currently,
we are exploring yet other catalytic variants of phos-
phine-based transformations for application in organic
chemistry, an exciting and versatile research area that
has remained dormant for more than a long period
but is now finally providing sustainable tools for
a range of highly practical synthetic transformations.
[9] a) C. J. OꢀBrien, J. L. Tellez, Z. S. Nixon, L. J. Kang,
A. L. Carter, S. R. Kunkel, K. C. Przeworski, G. A.
Chass, Angew. Chem. 2009, 121, 6968–6971; Angew.
Chem. Int. Ed. 2009, 48, 6836–6839; b) H. Fritzsche, F.
Korte, U. Hasserodt, Chem. Ber. 1964, 97, 1988–1993;
c) K. L. Marsi, J. Org. Chem. 1974, 39, 265–267; d) L.
McKinstry, T. Livinghouse, Tetrahedron 1994, 50, 6145–
6154.
[10] J. R. Harris, M. T. Haynes, A. M. Thomas, K. A. Woer-
pel, J. Org. Chem. 2010, 75, 5083–5091.
[11] H. A. van Kalkeren, S. H. A. M. Leenders, C. R. A.
Hommersom, F. P. J. T. Rutjes, F. L. van Delft, Chem.
Eur. J. 2011, 17, 11290–11295.
Experimental Section
General Procedure
The azide was dissolved in dry dioxane (0.2M) and phenylsi-
lane (1.5 equiv.) and 1-phenyl-dibenzophosphole (5 mol%)
were added. The reaction mixture was refluxed for 16 h and
then water (2 equiv.) was added and the mixture was stirred
at room temperature until the evolution of gas had ceased.
The solvent was evaporated and the crude product was puri-
fied by flash column chromatography to yield the amine.
[12] a) E. D. Goddard-Borger, R. V. Stick, Org. Lett. 2007,
9, 3797–3800; b) T. M. V. D. Pinho e Melo, in: Organic
Azides: Syntheses and Applications, (Ed.: K. B. S.
Brꢂse), John Wiley & Sons, Chicester, 2010, pp 53–94.
[13] a) V. D. Bock, H. Hiemstra, J. H. van Maarseveen, Eur.
J. Org. Chem. 2006, 51–68; b) V. V. Rostovtsev, L. G.
Green, V. V. Fokin, K. B. Sharpless, Angew. Chem.
2002, 114, 2708–2711; Angew. Chem. Int. Ed. 2002, 41,
2596–2599; c) S. Brꢂse, C. Gil, K. Knepper, V. Zimmer-
mann, Angew. Chem. 2005, 117, 5320–5374; Angew.
Chem. Int. Ed. 2005, 44, 5188–5240.
Acknowledgements
C. A. Hommersom is kindly acknowledged for her analytical
contributions. This research has been performed within the
framework of the CatchBio program. The authors gratefully
acknowledge the support of the Smart Mix Program of the
Netherlands Ministry of Economic Affairs and the Nether-
lands Ministry of Education, Culture and Science.
References
[14] a) N. W. Mitzel, K. Angermaier, H. Schmidbaur, Chem.
Ber. 1994, 127, 841–844; b) N. W. Mitzel, A. Schier, H.
Beruda, H. Schmidbaur, Chem. Ber. 1992, 125, 1053–
1059.
[1] A. W. Johnson, Ylides and imines of phosphorus, Wiley,
New York, 1993.
[2] K. C. K. Swamy, N. N. B. Kumar, E. Balaraman,
K. V. P. P. Kumar, Chem. Rev. 2009, 109, 2551–2651.
[3] R. Appel, Angew. Chem. 1975, 87, 863–874; Angew.
Chem. Int. Ed. Engl. 1975, 14, 801–811.
[4] a) H. Staudinger, J. Meyer, Helv. Chim. Acta 1919, 2,
635–646; b) Y. G. Gololobov, I. N. Zhmurova, L. F. Ka-
sukhin, Tetrahedron 1981, 37, 437–472.
[5] a) J. I. G. Cadogan, Organophosphorus reagents in or-
ganic synthesis, Academic Press, London, New York,
1979; b) D. H. Valentine, J. H. Hillhouse, Synthesis
2003, 317–334.
[15] Reuse of the catalyst gave identical results as with the
fresh catalyst. See the Supporting Information for more
details on catalyst recovery.
[16] a) R. J. Gaughran, J. P. Picard, J. V. R. Kaufman, J. Am.
Chem. Soc. 1954, 76, 2233–2236; b) M. L. Gross, I. M.
Takakis, G. G. Tsantali, G. W. Haas, D. Giblin, J. Mass
Spectrom. 1999, 34, 1137–1153.
[17] Stacked 1H and 31P NMR spectra for all reaction are
present in the Supporting Information.
Adv. Synth. Catal. 0000, 000, 0 – 0
ꢁ 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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