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J. Chen et al.
Cluster
Synlett
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1448.
reaction was quenched with sat. aq NaHCO3 (4 mL), and the
mixture was extracted with EtOAc (3 × 4 mL). The organic layer
was washed with H2O (3 × 4 mL), dried (Na2SO4), filtered, and
concentrated under reduced pressure. The crude product was
purified by flash column chromatography (silica gel).
N-(4-Chloro-2-methylphenyl)acetamide (2b)
The general procedure gave a 93:7 mixture of products 2b and
2b′ in 98% yield. 2b was isolated as a white solid; yield: 33.4 mg
(91%); mp 140–141 °C. 1H NMR (400 MHz, CDCl3): δ = 7.69 (d,
J = 9.2 Hz, 1 H), 7.16 (d, J = 6.3 Hz, 2 H), 6.99 (br s, 1 H), 2.22 (s, 3
H), 2.19 (s, 3 H). 13C NMR (100 MHz, CDCl3): δ = 168.4, 134.2,
131.1, 130.3, 130.3, 126.7, 124.5, 24.3, 17.7. HRMS (ESI): m/z [M
+ H]+ calcd for C9H1135ClNO: 184.0524; found: 184.0520.
N-(3-Bromo-4-chlorophenyl)acetamide (2d) and N-(3-
Bromo-2-chlorophenyl)acetamide (2d′)
(4) (a) Zhong, H.; Yang, D.; Wang, S.; Huang, J. Chem. Commun.
2012, 48, 3236. (b) Yu, Q.; Zhang, N.; Huang, J.; Lu, S.; Zhu, Y.;
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Hu, L.; Chen, Z.; Huang, J. Chem. Sci. 2015, 6, 5768.
(5) Friedel, C.; Crafts, J. M. C. R. Hebd. Seances Acad. Sci. 1877, 84,
1392.
The general procedure gave an 85:15 mixture of the products
2d and 2d′ in 98% yield.
(6) Bao, W.; Wang, Z.; Li, Y. J. Org. Chem. 2003, 68, 591.
(7) (a) Carreno, M. C.; Garcia Ruano, J. L.; Sanz, G.; Toledo, M. A.;
Urbano, A. J. Org. Chem. 1995, 60, 5328. (b) Zhao, J.; Jia, X.; Zhai,
H. Tetrahedron Lett. 2003, 44, 9371. (c) Vyas, P. V.; Bhatt, A. K.;
Ramachandraiah, G.; Bedekar, A. V. Tetrahedron Lett. 2003, 44,
4085. (d) Barhate, N. B.; Gajare, A. S.; Wakharkar, R. D.; Bedekar,
A. V. Tetrahedron Lett. 1998, 39, 6349.
2d: White solid; yield: 41.4 mg (83%); mp 118–119 °C. 1H NMR
(400 MHz, CDCl3): δ = 7.87 (d, J = 2.1 Hz, 1 H), 7.51 (br s, 1 H),
7.38 (dt, J = 15.8, 5.4 Hz, 2 H), 2.18 (s, 3 H). 13C NMR (100 MHz,
CDCl3): δ = 168.4, 137.2, 130.3, 129.5, 124.6, 122.5, 119.7, 24.5.
HRMS (ESI): m/z [M + H]+ calcd for C8H8Br79Cl35NO: 247.9472;
found: 247.9468.
1
2d′: White solid; yield: 7.3 mg (15%); mp 118–119 °C. H NMR
(8) Makosza, M. Pure Appl. Chem. 2009, 72, 1399.
(9) Chloroarenes 2a–j; General Procedure
(400 MHz, CDCl3): δ = 8.62 (s, 1 H), 7.65–7.45 (m, 1 H), 7.22 (d,
J = 8.5 Hz, 1 H), 7.17 (dd, J = 8.5, 2.1 Hz, 1 H), 2.25 (s, 3 H).
13C NMR (100 MHz, CDCl3): δ = 168.4, 137.3, 130.3, 129.5, 124.6,
122.5, 119.7, 24.5. HRMS (ESI): m/z [M + H]+ calcd for C8H7Br79Cl35NO:
247.9472; found: 247.9467.
A mixture of anilide or ether 1 (0.2 mmol), NCS (0.26 mmol),
D-CSA (0.1 mmol), and imidazolium salt 8 (0.01 mmol) in 1,4-
dioxane (1 mL) was stirred at r.t. (25 °C) under air for 24 h.
When the substrate was completely consumed (GC–MS), the
© Georg Thieme Verlag Stuttgart · New York — Synlett 2015, 26, 2831–2834