Green Chemistry
ARTICLE
DOI: 10.1039/C5GC00684H
Journal Name
substitution seems less favourable than a Friesꢀtype rearrangeꢀ Electronic Supplementary Information (ESI) available: characterisation
5
6, 57, 58
ment that transforms ether
5
to arylalkane
6
instead.
As data and NMR spectra. See DOI: 10.1039/b000000x/
1
.
J. Blacker and M. T. Williams, Pharmaceutical Process
Development: Current Chemical and Engineering Challenges,
Royal Society of Chemistry, 2011.
A. W. Williamson, Q. J. Chem. Soc., 1852, 4, 229ꢀ239.
P. T. Anastas and J. C. Warner, Green Chemistry: Theory and
Practice, Oxford University Press, 2000.
P. A. Wender and B. L. Miller, Nature, 2009, 460, 197ꢀ201.
D. J. C. Constable, P. J. Dunn, J. D. Hayler, G. R. Humphrey, J.
Leazer, Johnnie L., R. J. Linderman, K. Lorenz, J. Manley, B. A.
Pearlman, A. Wells, A. Zaks and T. Y. Zhang, Green Chem.,
2007, 9, 411ꢀ420.
such, a pathway might be operative in which the ether is conꢀ
verted to the starting alcohols which then form the sideꢀ
products via a FriedelꢀCrafts reaction.
2.
3
.
Conclusions
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5
.
.
In summary, we have demonstrated that ethers can be prepared
from readily available benzylic alcohols and phenols under
mild and environmentally benign conditions. Besides giving
access to new products, it provides another example of remarkꢀ
able chemoselectivity that can be obtained by employing an
6
.
E. Emer, R. Sinisi, M. G. Capdevila, D. Petruzziello, F. De
Vincentiis and P. G. Cozzi, Eur. J. Org. Chem., 2011, 2011, 647ꢀ
6
66.
M. Bandini and M. Tragni, Org. Biomol. Chem., 2009, 7, 1501ꢀ
507.
Y. Miyake, S. Uemura and Y. Nishibayashi, ChemCatChem,
009, 1, 342ꢀ356.
R. Kumar and E. V. Van der Eycken, Chem. Soc. Rev., 2013, 42,
121ꢀ1146.
appropriate NHCꢀgold(I) complex as catalyst. Investigations to 7.
use secondary benzylic alcohols as protoꢀelectrophiles to react
1
8
.
with nucleophiles other than phenols are currently ongoing in
our laboratories.
2
9.
1
1
1
1
1
0.
O. Debleds, E. Gayon, E. Vrancken and J.ꢀM. Campagne,
Beilstein J. Org. Chem., 2011, 7, 866ꢀ877.
X.ꢀw. Yan, Q. Zhang, W. Wei and J.ꢀx. Ji, Tetrahedron Lett.,
Experimental
1.
2.
3.
General information
2
014, 55, 3750ꢀ3752.
V. Terrasson, S. Marque, M. Georgy, J.ꢀM. Campagne and D.
Prim, Adv. Synth. Catal., 2006, 348, 2063ꢀ2067.
X. Giner, P. Trillo and C. Nájera, J. Organomet. Chem., 2011,
696, 357ꢀ361.
All reagents were obtained through commercial suppliers and
were used as received. Unless otherwise stated, all alcohols
were used as their racemate. [Au(NHC)(CH CN)][BF ],
3
4
Cl
14.
15.
L. Li, A. Zhu, Y. Zhang, X. Fan and G. Zhang, RSC Advances,
[
[
{Au(NHC)} (ꢁꢀOH)][BF ] (NHC = IPr, SIPr and IPr ) and
2 4
2
013, 4, 4286ꢀ4291.
Au(L)(NTf )] (L = IPr, IPrCl,, PPh ) were synthesised accordꢀ
2
3
Z. Zhu and J. H. Espenson, J. Org. Chem., 1996, 61, 324ꢀ328.
P. Salehi, N. Iranpoor and F. Kargar Behbahani, Tetrahedron,
4
4, 46, 47, 59, 60
ing to previous reports.
All reactions were set up on 16.
1
998, 54, 943ꢀ948.
Y. Nishibayashi, I. Wakiji and M. Hidai, J. Am. Chem. Soc., 2000,
22, 11019ꢀ11020.
the benchtop in screw cap vials with Teflon seal inserts and
carried out under an atmosphere of air. Flash column chromaꢀ
tography was performed using silica gel.
1
7.
1
18.
19.
G. V. M. Sharma, T. Rajendra Prasad and A. K. Mahalingam,
Tetrahedron Lett., 2001, 42, 759ꢀ761.
Kimberly J. Miller and Mahdi M. AbuꢀOmar, Eur. J. Org. Chem.,
General procedure for formation of ethers
2
003, 1294ꢀ1299.
K. Iwanami, K. Yano and T. Oriyama, Synthesis, 2005, 2669ꢀ
672.
Y. Liu, R. Hua, H.ꢀB. Sun and X. Qiu, Organometallics, 2005, 24,
819ꢀ2821.
Cl
To [Au(IPr )(MeCN)][BF ] (1c) (1.0 mol%) were added benꢀ 20.
4
2
zylic alcohol
and toluene (0ꢀ100 ꢁL). The reaction mixture was stirred at 50
C or 80 °C. After the reaction mixture was cooled down, the
crude product was purified by flash column chromatography on
2 (0.25 mmol), phenol 3 (1.25 mmol, 5 equiv.)
2
2
1.
2.
2
°
L. Herkert, S. L. J. Green, G. Barker, D. G. Johnson, P. C. Young,
S. A. Macgregor and A.ꢀL. Lee, Chem. Eur. J., 2014, 20, 11540ꢀ
11548.
R. Sanz, A. Martínez, J. M. ÁlvarezꢀGutiérrez and F. Rodríguez,
Eur. J. Org. Chem., 2006, 2006, 1383ꢀ1386.
6
1
silica gel (petroleum ether/diethyl ether = 9/1).
2
3.
Acknowledgements
24.
R. Sanz, A. Martínez, D. Miguel, J. M. ÁlvarezꢀGutiérrez and F.
Rodríguez, Adv. Synth. Catal., 2006, 348, 1841ꢀ1845.
K. Motokura, N. Nakagiri, K. Mori, T. Mizugaki, K. Ebitani, K.
Jitsukawa and K. Kaneda, Org. Lett., 2006, 8, 4617ꢀ4620.
J.ꢀL. Yu, H. Wang, K.ꢀF. Zou, J.ꢀR. Zhang, X. Gao, D.ꢀW. Zhang
and Z.ꢀT. Li, Tetrahedron, 2013, 69, 310ꢀ315.
The EPSRC and ERC are gratefully acknowledged for support. 25.
Umicore AG is acknowledged for their generous gift of materiꢀ
2
6.
als. The EPSRC National Mass Spectrometry Service Centre
NMSSC) is gratefully acknowledged for HRMS analyses. 27.
(
A. Corma and M. Renz, Angew. Chem. Int. Ed., 2007, 46, 302ꢀ
3
04.
S.P.N. is a Royal Society Wolfson Research Merit Award holdꢀ
er.
2
8.
M. Hellal, F. C. Falk, E. Wolf, M. Dryzhakov and J. Moran, Org.
Biomol. Chem., 2014, 12, 5990ꢀ5994.
2
3
9.
0.
H. S. Schier and A., Z. Naturforsch., 2011, 66b, 329ꢀ350.
H. G. Raubenheimer and H. Schmidbaur, J. Chem. Educ., 2014,
Notes and references
9
1, 2024ꢀ2036.
3
3
1.
2.
J. Muzart, Tetrahedron, 2008, 64, 5815ꢀ5849.
B. Biannic and A. Aponick, Eur. J. Org. Chem., 2011, 2011,
*
Eꢀmail: snolan@stꢀandrews.ac.uk.
‡
EaStCHEM School of Chemistry, University of St Andrews
St Andrews, KY16 9ST (UK).
6
605ꢀ6617.
3
3
3
3.
4.
5.
A. B. Cuenca, G. Mancha, G. Asensio and M. MedioꢀSimón,
Chem. Eur. J., 2008, 14, 1518ꢀ1523.
M. Georgy, V. Boucard and J.ꢀM. Campagne, J. Am. Chem. Soc.,
§
Chemistry Department, College of Science, King Saud Univerꢀ
sity, P.O. Box 2455, Riyadh 11451, (Saudi Arabia)
2
005, 127, 14180ꢀ14181.
N. Ibrahim, A. S. K. Hashmi and F. Rominger, Adv. Synth. Catal.,
011, 353, 461ꢀ468.
2
6
| J. Name., 2012, 00, 1-3
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