G
E. Yamaguchi et al.
Special Topic
Synthesis
19F NMR (470 MHz, CDCl3): δ = –67.43 (d, J = 8.1 Hz, 3 F).
MS (EI+): m/z = 214.06 [M]+.
References
(1) (a) Isanbor, C.; O’Hagan, D. J. Fluorine Chem. 2006, 127, 303.
(b) Kirk, K. L. J. Fluorine Chem. 2006, 127, 1013. (c) Muller, K.;
Faeh, C.; Diederich, F. Science 2007, 317, 1881. (d) Hagmann, W.
K. J. Med. Chem. 2008, 51, 4359.
(2) (a) Fluorine in Medicinal Chemistry and Chemical Biology;
Ojima, I., Ed.; Wiley: Chichester, 2009. (b) Bégué, J.-P.; Bonnet-
Delphon, D. Bioorganic and Medicinal Chemistry of Fluorine;
John Wiley & Sons: Hoboken, 2008.
4,4,4-Trifluoro-2-phenylbutan-2-ol (2q)18
Prepared according to the typical procedure. The product (54.8 mg,
0.27 mmol, 90%) was obtained as a colorless oil.
Rf = 0.3 (n-hexane/EtOAc, 10:1).
IR (neat): 2927, 1261 cm–1
.
1H NMR (500 MHz, CDCl3): δ = 7.46 (dd, J = 8.0, 1.2 Hz, 2 H), 7.37 (t, J =
8.0 Hz, 2 H), 7.29 (td, J = 8.0, 1.2 Hz, 1 H), 2.70–2.60 (m, 2 H), 2.21 (s, 1
H), 1.71 (s, 3 H).
13C NMR (125 MHz, CDCl3): δ = 146.1, 128.4, 127.4, 125.8 (q, J = 276.6
Hz), 124.3, 71.9, 46.5 (q, J = 25.0 Hz), 29.6.
19F NMR (470 MHz, CDCl3): δ = –59.96 (t, J = 10.8 Hz, 3 F).
MS (EI+): m/z = 204.06 [M]+.
(3) For selected recent reviews on C–CF3 bond-forming reaction,
see: (a) Ma, J.-A.; Cahard, D. Chem. Rev. 2004, 104, 6119.
(b) Shimizu, M.; Hiyama, T. Angew. Chem. Int. Ed. 2004, 44, 214.
(c) Ma, J.-A.; Cahard, D. J. Fluorine Chem. 2007, 128, 975.
(d) Prakash, G. K.; Hu, J. Acc. Chem. Res. 2007, 40, 921. (e) Ma, J.-A.;
Cahard, D. Chem. Rev. 2008, 108, PR1. (f) Uneyama, K.; Katagiri,
T.; Amii, H. Acc. Chem. Res. 2008, 41, 817. (g) Kumadaki, I.; Ando,
A.; Sato, K.; Tarui, A.; Omote, M. Synthesis 2010, 1865.
(h) Shibata, N.; Matsnev, A.; Cahard, D. Beilstein J. Org. Chem.
2010, 6, 65. (i) Dilman, A. D.; Levin, V. V. Eur. J. Org. Chem. 2011,
831. (j) Furuya, T.; Kamlet, A. S.; Ritter, T. Nature 2011, 473, 470.
(k) Qing, F.-L.; Zheng, F. Synlett 2011, 1052. (l) Roy, S.; Gregg, B.
T.; Gribble, G. W.; Le, V.-D.; Roy, S. Tetrahedron 2011, 67, 2161.
(m) Tomashenko, O. A.; Grushin, V. V. Chem. Rev. 2011, 111,
4475. (n) Macé, Y.; Magnier, E. Eur. J. Org. Chem. 2012, 2479.
(o) Soloshonok, V.; Aceña, J.; Sorochinsky, A. Synthesis 2012, 44,
1591. (p) Studer, A. Angew. Chem. Int. Ed. 2012, 51, 8950. (q) Liu,
H.; Gu, Z.; Jiang, X. Adv. Synth. Catal. 2013, 355, 617. (r) Zhang,
C.-P.; Chen, Q.-Y.; Guo, Y.; Xiao, J.-C.; Gu, Y.-C. Coord. Chem. Rev.
2014, 261, 28.
(4) (a) Alvernhe, G.; Langlois, B.; Laurent, A.; Le Drean, I.; Selmi, A.;
Weissenfels, M. Tetrahedron Lett. 1991, 32, 643. (b) Schenck, H.
A.; Lenkowski, P. W.; Choudhury-Mukherjee, I.; Ko, S. H.;
Stables, J. P.; Patel, M. K.; Brown, M. L. Bioorg. Med. Chem. 2004,
12, 979. (c) Muzalevskiy, V. M.; Nenajdenko, V. G.; Rulev, A. Y.;
Ushakov, I. A.; Romanenko, G. V.; Shastin, A. V.; Balenkova, E. S.;
Haufe, G. Tetrahedron 2009, 65, 6991. (d) Rudler, H.; Parlier, A.;
Denneval, C.; Herson, P. J. Fluorine Chem. 2010, 131, 738. (e) Ye,
Y.; Kunzi, S. A.; Sanford, M. S. Org. Lett. 2012, 14, 4979. (f) Li, Z.;
Cui, Z.; Liu, Q. Org. Lett. 2013, 15, 406.
Synthesis of the Anthraquinone-Based Photocatalyst: N-Benzyl-
9,10-dioxo-9,10-dihydroanthracene-2-carboxamide (3e)19
To a solution of AQN-2-CO2H (1.0 g, 4.0 mmol) in toluene (20 mL) was
added SOCl2 (0.43 mL, 6.0 mmol, 1.5 equiv) and one drop of DMF at
room temperature. The resulting solution was heated at reflux for 2 h.
After cooling to room temperature, the solvent was removed under
reduced pressure. The residue was diluted with CH2Cl2 (10 mL) and
added to a solution of benzylamine (0.66 mL, 6.0 mmol, 1.5 equiv)
and Et3N (0.83 mL, 6.0 mmol, 1.5 equiv) in CH2Cl2 (10 mL) at room
temperature. After being stirred for 17 hours, the reaction mixture
was diluted with CH2Cl2 (20 mL) and H2O (20 mL). The aqueous layer
was extracted with CH2Cl2 (3 × 30 mL). The combined organic layers
were washed with brine, dried over MgSO4 and concentrated in vac-
uo. Purification of the residue by flash chromatography on silica gel
(CHCl3/MeOH, 95:5) provided N-benzyl-9,10-dioxo-9,10-dihydroan-
thracene-2-carboxamide (1.11 g, 3.3 mmol, 82%) as an off-white sol-
id.
Mp >200 °C; Rf = 0.2 (CHCl3/MeOH, 95:5).
IR (neat): 2925, 1674, 1329, 1284, 1134, 1003, 706 cm–1
.
1H NMR (500 MHz, DMSO-d6): δ = 9.55 (t, J = 5.7 Hz, 1 H), 8.69 (s, 1 H),
8.37 (d, J = 8.0 Hz, 1 H), 8.29 (d, J = 8.6 Hz, 1 H), 8.25–8.21 (m, 2 H),
7.96–7.94 (m, 2 H), 7.37–7.25 (m, 4 H), 4.54 (d, J = 5.7 Hz, 2 H).
13C NMR (125 MHz, DMSO-d6): δ = 182.2, 164.7, 139.3, 139.1, 134.69,
134.67, 133.15, 133.12, 133.08, 132.9, 128.4, 127.4, 127.2, 126.90,
126.87, 126.84, 125.6, 42.9; (two carbon atoms were overlapped).
(5) For examples of electrophilic trifluoromethylation of carbonyl
compounds, see: (a) Umemoto, T.; Ishihara, S. J. Am. Chem. Soc.
1993, 115, 2156. (b) Umemoto, T.; Adachi, K. J. Org. Chem. 1994,
59, 5692. (c) Ma, J. A.; Cahard, D. J. Org. Chem. 2003, 68, 8726.
(d) Noritake, S.; Shibata, N.; Nomura, Y.; Huang, Y.; Matsnev, A.;
Nakamura, S.; Toru, T.; Cahard, D. Org. Biomol. Chem. 2009, 7,
3599. (e) Allen, A. E.; Macmillan, D. W. C. J. Am. Chem. Soc. 2010,
132, 4986.
MS (DART): m/z = 342.1 [M + H]+.
(6) For examples of radical trifluoromethylation of carbonyl com-
pounds, see: (a) Miura, K.; Taniguchi, M.; Nozaki, K.; Oshima, K.;
Utimoto, K. Tetrahedron Lett. 1990, 31, 6391. (b) Langlois, B. R.;
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Y.; Mikami, K. Org. Lett. 2005, 7, 4883. (d) Itoh, Y.; Mikami, K.
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2006, 127, 539. (g) Itoh, Y.; Mikami, K. Tetrahedron 2006, 62,
7199. (h) Mikami, K.; Tomita, Y.; Ichikawa, Y.; Amikura, K.; Itoh,
Y. Org. Lett. 2006, 8, 4671. (i) Nagib, D. A.; Scott, M. E.;
MacMillan, D. W. C. J. Am. Chem. Soc. 2009, 131, 10875. (j) Pham,
P. V.; Nagib, D. A.; MacMillan, D. W. C. Angew. Chem. Int. Ed.
2011, 50, 6119. (k) Jiang, H.; Cheng, Y.; Zhang, Y.; Yu, S. Eur. J.
Org. Chem. 2013, 5485. (l) Li, L.; Chen, Q. Y.; Guo, Y. J. Org. Chem.
2014, 79, 5145. (m) Wang, Y. F.; Lonca, G. H.; Chiba, S. Angew.
Funding Information
This work was supported by Takeda Science Foundation.
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Supporting Information
Supporting information for this article is available online at
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© Georg Thieme Verlag Stuttgart · New York — Synthesis 2018, 50, A–H