of the optimal catalyst to achieve the desired chemo- or
enantioselectivity in new transformations. Complex 1 can
also be used for the straightforward preparation of supported
catalysts, as demonstrated in the case of PS2–PAu, which
shows an excellent recyclability.
J. Schaebs, G. Hwang, F. Mistry, R. Jones, J. Trotter and
F. Aubke, J. Am. Chem. Soc., 1992, 114, 8972–8980;
(c) [Au(NCMe)2](SbCl6) was prepared from AuCl with SbCl5 in
acetonitrile: A. P. Zuur and W. L. Groeneveld, Recl. Trav. Chim.
Pays-Bas, 1967, 86, 1089–1102; (d) Acetonitrile solutions of Au+
with weakly coordinating anions have been obtained by electro-
chemical methods: R. Kissner, P. Latal and G. Geier, Chem.
Commun., 1993, 136–137, and references therein.
We thank the MICINN (CTQ2010-16088/BQU, CTQ2008-
00947/BQU, and Consolider Ingenio 2010, Grant CSD2006-
0003), the AGAUR (2009SGR47 and 2009SGR623), and the
ICIQ Foundation for financial support.
10 Salts containing the [Au(NCMe)2]+ cation were used for the
synthesis of other bis-nitrile gold(I) complexes: (a) F. Farha and
R. T. Iwamoto, Inorg. Chem., 1965, 4, 844–848; (b) K. D. Shimizu
and J. Rebek, Proc. Natl. Acad. Sci. U. S. A., 1996, 93, 4257–4260.
11 The oxidation of Au metal with nitrosonium salts gave
[Au(NCPh)2]+AÀ (A = BF4 and SbF6) in low yield. Contrary
to that stated, yields based on gold for the preparation of
[Au(NCPh)2]+AÀ with NOBF4 or NO2SbF6 were 40% (A = BF4)
and 15% (A = SbF6) since excess gold metal (1.9–4.3 equiv.) was
used: Y. J. Yau and D. M. P. Mingos, J. Chem. Soc., Dalton
Notes and references
1 (a) E. Jimenez-Nu´ nez and A. M. Echavarren, Chem. Rev., 2008,
´
108, 3326–3350; (b) D. J. Gorin, B. D. Sherry and F. D. Toste,
Chem. Rev., 2008, 108, 3351–3378; (c) V. Michelet, P. Y. Toullec
and J. P. Genet, Angew. Chem., Int. Ed., 2008, 47, 4268–4315;
(d) A. S. K. Hashmi, Chem. Rev., 2007, 107, 3180–3211;
Trans., 1997, 1103–1111. Similarly, [Au(NCtBu)2]+BF4 was
À
prepared in 25% yield based on gold.
(e) A. Furstner, Chem. Soc. Rev., 2009, 38, 3208–3221.
pez-Carrillo, M. Raducan, P. Perez-
´ ´
Galan, C. Ferrer and A. M. Echavarren, J. Org. Chem., 2008, 73,
7721–7730; (b) D. Benitez, N. D. Shapiro, E. Tkatchouk, Y. Wang,
W. A. Goddard III and F. D. Toste, Nat. Chem., 2009, 1, 482–486;
(c) G. C. Fortman and S. P. Nolan, Organometallics, 2010, 29,
4579–4583.
¨
2 (a) C. H. M. Amijs, V. Lo
12 Heterogenized Au(I) catalysts: (a) A. Corma, E. Gutierrez-Puebla,
M. Iglesias, A. Monge, S. Perez-Ferreras and F. Sanchez, Adv.
Synth. Catal., 2006, 348, 1899–1907; (b) A. Corma, C. Gonzalez-
Arellano, M. Iglesias, S. Perez-Ferreras and F. Sanchez, Synlett,
´
2007, 1771–1774; (c) Y. Yang, B. Beele and J. Blumel, J. Am.
Chem. Soc., 2008, 130, 3771–3773.
¨
13 Lead references on heterogenized Au(III) catalysts: (a) J. Guzman
and B. C. Gates, Angew. Chem., Int. Ed., 2003, 42, 690–693;
(b) J. C. Fierro-Gonzalez, V. A. Bhirud and B. C. Gates, Chem.
Commun., 2005, 5275–5277; (c) V. Aguilar-Guerrero and
B. C. Gates, Chem. Commun., 2007, 3210–3212; (d) C. del Pozo,
A. Corma, M. Iglesias and F. Sanchez, Organometallics, 2010, 29,
4491–4498; (e) A. K. Ganai, R. Bhardwaj, S. Hotha, S. S. Gupta
and B. L. V. Prasad, New J. Chem., 2010, 34, 2662–2670.
14 A new complex [Ag(MeCN)2](SbF6) (2b) was also prepared as a
non-hygroscopic and relatively light stable silver(I) complex. See
ESIw for details.
3 (a) S. P. Nolan, Acc. Chem. Res., 2010, 44, 91–100; (b) S. Gaillard,
P. Nun, A. M. Z. Slawin and S. P. Nolan, Organometallics, 2010,
29, 5402–5408.
4 (a) N. Mezailles, L. Ricard and F. Gagosz, Org. Lett., 2005, 7,
´
4133–4136; (b) A. S. K. Hashmi, M. C. Blanco, E. Kurpejovic,
W. Frey and J. W. Bats, Adv. Synth. Catal., 2006, 348, 709–713;
(c) A. S. K. Hashmi, A. Loos, A. Littmann, I. Braun, J. Knight,
S. Doherty and F. Rominger, Adv. Synth. Catal., 2009, 351,
576–582; (d) H. Ito, H. Ohmiya and M. Sawamura, Org. Lett.,
2010, 12, 4380–4383; (e) M. Alcarazo, T. Stork, A. Anoop,
W. Thiel and A. Furstner, Angew. Chem., Int. Ed., 2010, 49,
¨
2542–2546; (f) M. Pazicky, A. Loos, M. J. Ferreira, D. Serra,
N. Vinokurov, F. Rominger, C. Jakel, A. S. K. Hashmi and
¨
M. Limbach, Organometallics, 2010, 29, 4448–4458.
15 (a) R. Martin and S. L. Buchwald, Acc. Chem. Res., 2008, 41,
1461–1473; (b) D. S. Surry and S. L. Buchwald, Angew. Chem., Int.
Ed., 2008, 47, 6338–6361.
16 (a) C. Nieto-Oberhuber, S. Lo
Chem. Soc., 2005, 127, 6178–6179; (b) C. Nieto-Oberhuber,
P. Perez-Galan, E. Herrero-Gomez, T. Lauterbach,
C. Rodrıguez, S. Lopez, C. Bour, A. Rosellon, D. J. Cardenas
and A. M. Echavarren, J. Am. Chem. Soc., 2008, 130, 269–279.
17 (a) E. Herrero-Gomez, C. Nieto-Oberhuber, S. Lopez, J. Benet-
Buchholz and A. M. Echavarren, Angew. Chem., Int. Ed., 2006, 45,
5455–5459; (b) P. Perez-Galan, N. Delpont, E. Herrero-Gomez,
´
pez and A. M. Echavarren, J. Am.
5 (a) C. Bartolome
J. M. Martın-Alvarez and P. Espinet, Inorg. Chem., 2008, 47,
1616–1624; (b) C. Bartolome Z. Ramiro, P. Perez-Galan,
C. Bour, M. Raducan, A. M. Echavarren and P. Espinet, Inorg.
Chem., 2008, 47, 11391–11397; (c) C. Bartolome, Z. Ramiro,
D. Garcıa-Cuadrado, P. Perez-Galan, M. Raducan, C. Bour,
A. M. Echavarren and P. Espinet, Organometallics, 2010, 29,
951–956; (d) C. Bartolome, D. Garcıa-Cuadrado, Z. Ramiro and
P. Espinet, Inorg. Chem., 2010, 49, 9758–9764; (e) A. S. K. Hashmi,
´
, M. Carrasco-Rando, S. Coco, C. Cordovilla,
´
´
´
´
´
,
´
´
´
´
´
´
´
´
´
´
´
´
´
´
´
´
´
F. Maseras and A. M. Echavarren, Chem.–Eur. J., 2010, 16,
5324–5332.
T. H. C. Lothschutz and F. Rominger, Adv. Synth. Catal., 2010,
352, 1315–1337.
¨
18 The Au–Au distance in
9 is 3.75 A, outside the range
(2.5–3.5 A) considered significant for aurophilic interactions. See:
(a) H. Schmidbaur and A. Schier, Chem. Soc. Rev., 2008, 37,
1931–1951. The Au–Au in the related complex (S)-BIPHEP(AuCl)2
is 3.099 A: (b) K. Aikawa, M. Kojima and K. Mikami, Angew.
Chem., Int. Ed., 2009, 48, 6073–6077.
6 (a) V. Lavallo, G. D. Frey, S. Kousar, B. Donnadieu and
G. Bertrand, Proc. Natl. Acad. Sci. U. S. A., 2007, 104,
13569–13573; (b) G. D. Frey, R. D. Dewhurst, S. Kousar,
B. Donnadieu and G. Bertrand, J. Organomet. Chem., 2008, 693,
1674–1682; (c) X. Zeng, M. Soleilhavoup and G. Bertrand, Org.
Lett., 2009, 11, 3166–3199; (d) X. Zeng, G. D. Frey, S. Kousar and
G. Bertrand, Chem.–Eur. J., 2009, 15, 3056–3060.
19 Recent review on asymmetric gold catalysis: S. Sengupta and
X. Shi, ChemCatChem, 2010, 2, 609–619.
20 M. J. Johansson, D. J. Gorin, S. T. Staben and F. D. Toste, J. Am.
Chem. Soc., 2005, 127, 18002–18003.
21 Details on the enantioselective gold(I)-catalyzed cycloadditions will
be reported separately.
7 (a) K. J. Kilpin, U. S. D. Paul, A.-L. Lee and J. D. Crowley, Chem.
Commun., 2010, 47, 328–330; (b) H. Teller, S. Flugge, R. Goddard
¨
and A. Furstner, Angew. Chem., Int. Ed., 2010, 49, 1949–1953.
¨
8 For the use of benzotriazole as weak ligand in Au(I)-catalyzed
reactions: (a) H. Duan, S. Sengupta, J. L. Petersen, N. G.
Akhmedov and X. Shi, J. Am. Chem. Soc., 2009, 131,
12100–12102; (b) Y. Chen, W. Yan, N. G. Akhmedov and
X. Shi, Org. Lett., 2010, 12, 344–347.
9 (a) [Au(NCMe)2](ClO4) was obtained in low yield by treating gold
powder with NOClO4 in MeCN: G. Bergerhoff, Z. Anorg. Allg.
Chem., 1964, 327, 139; (b) [Au(NCMe)2](SbF6) was isolated and
characterized by the solvolysis of [Au(CO)2](Sb2F11): H. Willner,
22 (a) C. Nieto-Oberhuber, M. P. Munoz, S. Lo
C. Nevado, E. Herrero-Gomez, M. Raducan and A. M. Echavarren,
Chem.–Eur. J., 2006, 12, 1677–1693; (b) C. Nieto-Oberhuber,
M. P. Munoz, S. Lopez, E. Jimenez-Nunez, C. Nevado,
E. Herrero-Gomez, M. Raducan and A. M. Echavarren, Eur. J.
pez, E. Jimenez-Nu´ nez,
´ ´
´
´
´
´
´
Org. Chem., 2006, 1677–1693; (c) C. Ferrer, M. Raducan, C. Nevado,
C. K. Claverie and A. M. Echavarren, Tetrahedron, 2007, 63,
6306–6316.
c
This journal is The Royal Society of Chemistry 2011
Chem. Commun., 2011, 47, 4893–4895 4895