Olga P. Pereshivko et al.
UPDATES
ray crystallographic data for 4d and 5d are available in the
Supporting Information.
[5] V. A. Peshkov, O. P. Pereshivko, S. Sharma, T. Megana-
than, V. S. Parmar, D. S. Ermolat’ev, E. V. Van der
Eycken, J. Org. Chem. 2011, 76, 5867–5872.
[6] M. J. Campbell, F. D. Toste, Chem. Sci. 2011, 2, 1369–
1378.
[7] N. R. Easton, D. R. Cassady, R. D. Dillard, J. Org.
Chem. 1964, 29, 1851–1855.
Acknowledgements
Support was provided by the Fund for Scientific Research
(FWO), Flanders and by the Research Fund of the University
of Leuven (KU Leuven). V.A.P. is grateful to the EMECW
(Triple I) for obtaining a doctoral scholarship. The authors
thank Ir. B. Demarsin for valuable help with HR-MS. J.J. and
L.V.M. thank the Hercules Foundation for supporting the
purchase of the single crystal diffractometer through project
AKUL/09/0035.
[8] For a focused review on ligand effects in homogeneous
Au catalysis, see: D. J. Gorin, B. D. Sherry, F. D. Toste,
Chem. Rev. 2008, 108, 3351–3378.
[9] A possible role of the Ag catalyst in accelerating the
double bond migration (4a!6) has already been inves-
tigated by us (see ref.[5]). For the study covering similar
migration aspects in the AuACTHNURGTNE(UNG III)-catalyzed synthesis of
2,5-disubstituted oxazoles, see: A. S. K. Hashmi, J. P.
Weyrauch, W. Frey, J. W. Bats, Org. Lett. 2004, 6, 4391–
4394.
[10] This 5-exo-dig versus 6-endo-dig competition was previ-
ously documented by Campbell and Toste in their pro-
cess involving cationic Au(I)-catalyzed cycloisomeriza-
tion of propargylic ureas (see ref.[6]). Similar competi-
tion was described in cationic Au(I)-catalyzed cycloiso-
merization of non-terminal propargylic amides, see:
a) A. S. K. Hashmi, A. M. Schuster, M. Schmuck, F.
Rominger, Eur. J. Org. Chem. 2011, 4595–4602;
b) A. S. K. Hashmi, A. M. Schuster, S. Gaillard, L. Cav-
allo, A. Poater, S. P. Nolan Organometallics 2011, 30,
6328–6337. Another relevant example of such competi-
tion was observed in a Ag(I)-catalyzed cycloisomeriza-
tion of propargylic guanidines (see refs.[1b,1c]). In most
cases as well as in the presented study 5-exo-dig cy-
clized products are prevailing.
References
[1] With this reference we would like to highlight several
processes relevant to the performed research: a) D. S.
Ermolat’ev, J. B. Bariwal, H. P. L. Steenackers, S. C. J.
De Keersmaecker, E. V. Van der Eycken, Angew.
Chem. 2010, 122, 9655–9658; Angew. Chem. Int. Ed.
2010, 49, 9465–9468; b) O. P. Pereshivko, V. A. Peshkov,
D. S. Ermolat’ev, S. Van Hove, K. Van Hecke, L. Van
Meervelt, E. V. Van der Eycken, Synthesis 2011, 1587–
1594; c) M. J. Gainer, N. R. Bennett, Y. Takahashi,
R. E. Looper, Angew. Chem. 2011, 123, 710–713;
Angew. Chem. Int. Ed. 2011, 50, 684–687; d) Y. Wang,
H. Shen, Z. Xie, Synlett 2011, 969–973; e) W.-J. Yoo,
C.-J. Li, Adv. Synth. Catal. 2008, 350, 1503–1506; f) H.
Feng, D. S. Ermolat’ev, G. Song, E. V. Van der Eycken,
Adv. Synth. Catal. 2012, 354, 505–509; g) J. Zhao, H.
Huang, C. Qi, H. Jiang, Eur. J. Org. Chem. 2012, DOI:
10.1002/ejoc.201200990; h) C. Madaan, S. Saraf, G.
Priyadarshani, P. P. Reddy, S. K. Guchhait, A. C.
Kunwar, B. Sridhar, Synlett 2012, 1955–1959.
[2] For selected reviews, see: a) C. Wei, L. Zhang and C.-J.
Li, Synlett 2004, 1472–1483; b) W.-J. Yoo, L. Zhao, C.-J.
Li, Aldrichimica Acta 2011, 44, 43–51; c) V. A. Peshkov,
O. P. Pereshivko, E. V. Van der Eycken, Chem. Soc.
Rev. 2012, 41, 3790–3807; d) L. Zani, C. Bolm, Chem.
Commun. 2006, 4263–4275.
[3] For selected examples, see: a) B. Yan, Y. Liu, Org. Lett.
2007, 9, 4323–4326; b) N. Sakai, N. Uchida, T. Konaka-
hara, Tetrahedron Lett. 2008, 49, 3437–3440; c) H. Li, J.
Liu, B. Yan, Y. Li, Tetrahedron Lett. 2009, 50, 2353–
2357; d) Y. Ohta, H. Chiba, S. Oishi, N. Fujii, H. Ohno,
J. Org. Chem. 2009, 74, 7052–7058; e) N. Chernyak, V.
Gevorgyan, Angew. Chem. 2010, 122, 2803–2806;
Angew. Chem. Int. Ed. 2010, 49, 2743–2746; f) D. Cher-
nyak, N. Chernyak, V. Gevorgyan, Adv. Synth. Catal.
2010, 352, 961–966; g) Q. Zhang, M. Chang, X. Y. Hu,
B. G. Li, J. X. Ji, J. Am. Chem. Soc. 2010, 132, 7256–
7257; h) E. R. Bonfield, C.-J. Li, Adv. Synth. Catal.
2008, 350, 370–374.
[11] This correlates with the drop of the double bond migra-
tion rate for the AgOTf/PPh3-catalyzed reaction in the
first model case (Table 1, entry 19).
[12] In this study only tosyl isocyanate 2 has been used. The
cationic Au(I)-catalyzed reaction with aromatic isocya-
nates proceeds in a different manner and requires
some more optimization which is currently ongoing in
our laboratory. These results will be reported in due
course. Ag(I) triflate-catalyzed reactions with aromatic
isocyanates has already been reported by us (see
ref.[5]).
[13] CCDC 904954 and CCDC 904955 contain the supple-
mentary crystallographic data for this paper. These
data can be obtained free of charge from The Cam-
m.ac.uk/data_request/cif.
[14] See the Supporting Information for details.
[15] For selected reviews, see: a) J.-M. Weibel, A. Blanc, P.
Pale, Chem. Rev. 2008, 108, 3149–3173; b) M. ꢂlvarez-
Corral, M. MuÇoz-Dorado, I. Rodrꢃguez-Garcꢃa, Chem.
Rev. 2008, 108, 3174–3198; c) P. Belmont, in: Silver in
Organic Chemistry, (Ed.: M. Harmata), John Wiley,
Hoboken, 2010, pp 143–165.
[16] For selected reviews, see: a) P. Belmont, E. Parker,
Eur. J. Org. Chem. 2009, 6075–6089; b) R. A. Widen-
hoefer, F. Song, in: Catalyzed Carbon-Heteroatom
Bond Formation, (Ed.: A. K. Yudin), Wiley-VCH,
Weinheim, 2010, pp 437–461; c) R. A. Widenhoefer, F.
Song, in: Catalyzed Carbon-Heteroatom Bond Forma-
tion, (Ed.: A. K. Yudin), Wiley-VCH, Weinheim, 2010,
[4] For the preparation of secondary N-alkylpropargyla-
mines, see: a) J. B. Bariwal, D. S. Ermolat’ev, E. V. Van
der Eycken, Chem. Eur. J. 2010, 16, 3281–3284; b) O. P.
Pereshivko, V. A. Peshkov, E. V. Van der Eycken, Org.
Lett. 2010, 12, 2638–2641.
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