Y. Sawama, M. Takubo, S. Mori, Y. Monguchi, H. Sajiki
(m, 4 H) ppm. 13C NMR (100 MHz, CDCl3): δ = 55.6, 114.3, (d, J = 8.0 Hz, 1 H), 9.33 (d, J = 8.6 Hz, 1 H) ppm. 13C NMR
FULL PAPER
126.1, 128.9, 129.9, 132.3, 133.2, 134.7, 165.0, 193.1, 194.7 ppm.
(125 MHz, CDCl3): δ = 124.4, 125.9, 127.1, 128.6, 128.8, 129.0,
129.4, 129.9, 130.9, 133.3, 134.1, 134.7, 135.1, 135.9, 194.6,
197.1 ppm. The NMR spectrum of 3p was identical to that report-
ed.[16t]
The NMR spectrum of 3g was identical to that reported.[16t]
1-(3-Methoxyphenyl)-2-phenylethane-1,2-dione (3h): 1H NMR
(400 MHz, CDCl3): δ = 3.86 (s, 3 H), 7.21 (dd, J = 1.6, 8.2 Hz, 1
H), 7.40 (t, J = 8.2 Hz, 1 H), 7.47–7.55 (m, 4 H), 7.66 (t, J =
7.2 Hz, 1 H), 7.97 (d, J = 7.7 Hz, 2 H) ppm. 13C NMR (100 MHz,
CDCl3): δ = 55.4, 112.8, 121.8, 123.1, 129.0, 129.8, 130.0, 132.9,
134.2, 134.8, 160.0, 194.4, 194.4 ppm. The NMR spectrum of 3h
was identical to that reported.[20]
1
1-Phenyl-2-(2-pyridinyl)ethane-1,2-dione (3q): H NMR (500 MHz,
CDCl3): δ = 7.48–7.53 (m, 3 H), 7.64 (t, J = 7.5 Hz, 1 H), 7.93–
7.95 (m, 3 H), 8.20 (d, J = 6.9 Hz, 1 H), 8.66 (d, J = 4.0 Hz, 1
H) ppm. 13C NMR (CDCl3): δ = 123.1, 128.1, 128.9, 129.5, 133.1,
134.6, 137.2, 149.8, 151.7, 195.1, 196.1 ppm. The NMR spectrum
of 3q was identical to that reported.[31]
1-(2-Methoxyphenyl)-2-phenylethane-1,2-dione (3i): 1H NMR
(400 MHz, CDCl3): δ = 3.56 (s, 3 H), 6.93 (d, J = 8.0 Hz, 1 H),
7.13 (t, J = 8.0 Hz, 1 H), 7.49 (dd, J = 1.2, 8.1 Hz, 2 H), 7.58–7.63
(m, 2 H), 7.92 (dd, J = 8.0, 8.1 Hz, 2 H), 8.03 (dd, J = 1.2, 8.1 Hz,
1 H) ppm. 13C NMR (100 MHz, CDCl3): δ = 55.7, 112.4, 121.6,
123.9, 128.7, 129.3, 130.6, 133.0, 133.7, 136.4, 160.4, 193.4,
194.6 ppm. The NMR spectrum of 3i was identical to that report-
ed.[16s]
1-Phenyl-2-(2-thienyl)ethane-1,2-dione (3r): 1H NMR (400 MHz,
CDCl3): δ = 7.18 (dd, J = 3.8, 4.8 Hz, 1 H), 7.51 (dd, J = 7.3,
7.7 Hz, 2 H), 7.66 (d, J = 7.7 Hz, 1 H); 7.80–7.85 (m, 2 H), 8.04
(d, J = 7.3 Hz, 2 H) ppm. 13C NMR (CDCl3): δ = 128.8, 128.9,
130.2, 132.5, 134.8, 136.7, 136.9, 139.8, 185.6, 192.0 ppm. The
NMR spectrum of 3o was identical to that reported.[32]
Supporting Information (see footnote on the first page of this arti-
1-(4-Hydroxyphenyl)-2-phenylethane-1,2-dione (3j): 1H NMR
(400 MHz, CDCl3): δ = 6.51 (br. s, 1 H), 6.90 (d, J = 8.4 Hz, 2 H),
7.50 (dd, J = 7.3, 7.7 Hz, 2 H), 7.65 (t, J = 7.3 Hz, 1 H), 7.87 (d,
J = 8.4 Hz, 2 H), 7.96 (d, J = 7.7 Hz, 2 H) ppm. 13C NMR
(100 MHz, CDCl3): δ = 116.1, 125.9, 129.0, 130.0, 132.8, 133.0,
135.0, 162.0, 193.4, 195.2 ppm. The NMR spectrum of 3j was iden-
tical to that reported.[16s]
1
cle): Copies of the H NMR spectra of the benzil products.
Acknowledgments
We thank the N. E. Chemcat Corporation for the kind gift of the
catalysts.
1-(4-Formylphenyl)-2-phenylethane-1,2-dione (3k): 1H NMR
(400 MHz, CDCl3): δ = 7.53 (dd, J = 7.7, 8.2 Hz, 2 H), 7.70 (t, J
= 7.7 Hz, 1 H), 7.97–8.03 (m, 4 H), 8.14 (d, J = 8.7 Hz, 2 H), 10.1
(s, 1 H) ppm. 13C NMR (100 MHz, CDCl3): δ = 129.0, 129.9,
129.9, 130.3, 132.4, 135.2, 136.8, 139.9, 191.3, 193.4, 193.5 ppm.
The NMR spectrum of 3k was identical to that reported.[16u]
[1] T. Higuchi, H. Ohtake, M. Hirobe, Tetrahedron Lett. 1991, 32,
7435–7438.
[2] a) T. Higuchi, H. Ohtake, M. Hirobe, Tetrahedron Lett. 1989,
30, 6545–6548; b) H. Ohtake, T. Higuchi, M. Hirobe, Tetrahe-
dron Lett. 1992, 33, 2521–2524.
[3] H. Ohtake, T. Higuchi, M. Hirobe, J. Am. Chem. Soc. 1992,
1,2-Bis(4-methoxyphenyl)ethane-1,2-dione
(3l):
1H
NMR
114, 10660–10663.
[4] T. Higuchi, C. Satake, M. Hirobe, J. Am. Chem. Soc. 1995, 117,
8879–8880.
(400 MHz, CDCl3): δ = 3.88 (s, 6 H), 6.97 (d, J = 9.0 Hz, 4 H),
7.96 (d, J = 9.0 Hz, 4 H) ppm. 13C NMR (100 MHz, CDCl3): δ =
55.6, 114.2, 126.2, 132.3, 164.8, 193.4 ppm. The NMR spectrum of
3l was identical to that reported.[20]
[5] R. Ito, N. Umezawa, T. Higuchi, J. Am. Chem. Soc. 2005, 127,
834–835.
[6] J. A. Fuentes, M. L. Clarke, Synlett 2008, 17, 2579–2582.
[7] D. X. Chen, C. M. Ho, Q. Y. R. Wu, P. R. Wu, F. M. Wong,
W. Wu , Tetrahedron Lett. 2008, 49, 4147–4148.
[8] L. Ye, L. Cui, G. Zhang, L. Zhang, J. Am. Chem. Soc. 2010,
132, 3258–3259.
1-(4-Methoxyphenyl)-2-(4-nitrophenyl)ethane-1,2-dione (3m): 1H
NMR (400 MHz, CDCl3): δ = 3.91 (s, 3 H), 7.00 (d, J = 8.9 Hz, 2
H), 7.97 (d, J = 8.9 Hz, 2 H), 8.16 (d, J = 9.0 Hz, 2 H), 8.34 (d, J
= 9.0 Hz, 2 H) ppm. 13C NMR (100 MHz, CDCl3): δ = 55.7, 114.6,
124.0, 125.4, 130.9, 132.6, 137.6, 151.1, 165.5, 191.3, 192.3 ppm.
[9] L. Ye, W. He, L. Zhang, J. Am. Chem. Soc. 2010, 132, 8550–
8551.
1
The H NMR spectrum of 3m was identical to that reported.[30]
[10] J. C. Lee, H.-J. Park, J. Y. Park, Tetrahedron Lett. 2002, 43,
5661–5663.
[11] A. Krebs, H. Colberg, U. Höpfner, H. Kimling, J. Odenthal,
Heterocycles 1979, 12, 1153–1156.
1-(4-Methoxyphenyl)-2-(3-nitrophenyl)ethane-1,2-dione (3n): 1H
NMR (400 MHz, CDCl3): δ = 3.87 (s, 3 H), 6.97 (d, J = 9.0 Hz, 2
H), 7.70 (dd, J = 7.8, 8.2 Hz, 1 H), 7.93 (d, J = 9.0 Hz, 2 H), 8.27
(d, J = 7.8 Hz, 1 H), 8.45 (d, J = 8.2 Hz, 1 H), 8.76 (s, 1 H) ppm.
13C NMR (100 MHz, CDCl3): δ = 55.6, 114.5, 124.4, 125.2, 128.5,
130.2, 132.5, 134.4, 135.2, 148.4, 165.4, 191.0, 191.6 ppm. MS (EI):
m/z = 285 (5) [M]+, 44 (15), 50 (10), 64 (5), 77 (15), 92 (10), 107
(5), 135 (100), 285 (5). HRMS (EI): calcd. for C15H11NO5 [M]+
285.0637; found 285.0631.
[12] Benzils are the substructure of natural products, see: a) L. Re,
B. Maurer, G. Ohloff, Helv. Chim. Acta 1973, 56, 1882–1894;
b) M. D. Rozwadowska, M. Chrzanowska, Tetrahedron 1985,
41, 2885–2890; W. Mahabusarakam, S. Deachathai, S. Phong-
paichit, C. Jansakul, W. C. Taylor, Phytochemistry 2004, 65,
1185–1191.
[13] Benzils show potent activity as a carboxylesterase inhibitor,
see: a) T. Harada, Y. Nakagawa, R. M. Wadkins, P. M. Potter,
C. E. Wheelock, Bioorg. Med. Chem. 2009, 17, 149–164; b)
C. C. Edwards, J. L. Hyatt, L. Tsurkan, F. Bai, C. Fraga, C. L.
Morton, E. L. Howard-Williams, P. M. Potter, M. R. Redinbo,
J. Mol. Biol. 2005, 352, 165–177; c) R. M. Wadkins, J. L. Hyatt,
X. Wei, K. J. P. Yoon, M. Wierdl, C. C. Edwards, C. L. Mor-
ton, J. C. Obenauer, K. Damodaran, P. Beroza, M. K. Danks,
P. M. Potter, J. Med. Chem. 2005, 48, 2906–2915; d) C.
Mousset, A. Giraud, O. Provot, A. Hamze, J. Bignon, J.-M.
Liu, S. Thoret, J. Dubois, J.-D. Brion, M. Alami, Bioorg. Med.
Chem. Lett. 2008, 18, 3266–3271.
1-(4-Acetylphenyl)-2-(4-methoxyphenyl)ethane-1,2-dione (3o): 1H
NMR (400 MHz, CDCl3): δ = 2.65 (s, 3 H), 3.90 (s, 3 H), 6.99 (d,
J = 9.0 Hz, 2 H), 7.95 (d, J = 9.0 Hz, 2 H), 8.06 (m, 4 H) ppm. 13
C
NMR (CDCl3): δ = 26.9, 55.7, 114.5, 125.8, 128.6, 130.1, 132.4,
136.2, 141.2, 165.2, 192.2, 193.8, 197.2 ppm. The NMR spectrum
of 3o was identical to that reported.[20]
1
1-(1-Naphthyl)-2-phenylethane-1,2-dione (3p): H NMR (500 MHz,
CDCl3): δ = 7.46–7.53 (m, 3 H), 7.61–7.67 (m, 2 H), 7.73–7.77 (m,
1 H), 7.92 (t, J = 8.6 Hz, 2 H), 8.04 (dd, J = 1.5, 8.6 Hz, 2 H), 8.11
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